Environmental Science For Architects DOMESTIC DWELLING INVESTIGATION Cameron Worboys // Jonathan Ballard // Jonathon Hughes // Lidan Xiaopp
Preface Environmental science in architecture provides us with the means to understand the full life cycle of a building. Our architecture is not merely a finished construction but entails a complex system between occupants and the spaces they inhabit. The built environment is responsible for 40% of the UK’s carbon emissions. With the ever-increasing awareness and social pressures on reducing our carbon footprint, it is our responsibility as architects to address this complex subject first hand. This investigation explores four separate dwellings, in an attempt to analyse, evaluate and improve environmental performance within a functional domestic setting.
Contents 4
Methodology
5
Jonathan Ballard
Location & Initial Building Analysis Energy Bill Analysis Building Fabric analysis Ventilation Solar heat gains Internal heat gains Balance point Comparative HLC & Balance Points Degree-days & Carbon Emissions Conclusion
37
Lidan Xiao
General information Experience of each space Heat loss calculation Ventilation analysis Solar gain Internal heating and light gain Balance points & degree-days Conclusion
62
Cameron Worboys
Initial Building Analysis Building Fabric Analysis Ventilation Analysis Solar Gains Internal Heat Gains Balance Point Degree-Days Conclusion
90
Jonathon Hughes
Site Analysis Fabric Analysis Ventilation Analysis Solar Gains Internal Heat Gains Balance points Degree-days Conclusion
120
Individual Analysis Conclusion
122
Re-design
144
Conclusion
146
Equations
Layout & User Comfort PassivHaus Plans Cavity Wall Design Cavity Wall Design – Continued Roof/Ceiling Design Floor Design Openings Design Geometric Bridging Building Fabric Analysis Air Tightness Ventilation Solar Gains Internal Gains Balance Point Comparative HLC & Balance Points Degree-days & Carbon Emissions
4
Methodology The main aim of this investigation is to carry out a rigorous analysis of the building envelope to establish how the main components and factors of the building affect its performance and occupant comfort and how it operates within its immediate environment. The initial step will be to identify the location of the building and draw plans including areas, volumes and opening sizes. We will look at strengths and weaknesses in the current envelope. User observation of current issues and comfort levels will be recorded as a basis to begin the in depth investigation. This information can be used to quantify ways in which occupants can gain more control for greater comfort and efficiency. An energy/carbon audit will begin with the calculation of u-values and an examination of heat flow through the envelope. We will examine in detail the building fabric construction including walls, floor, roof, windows and doors, identifying any incidence of structural (homogenous and non-homogenous) and geometric bridging. This will enable us to calculate a Heat Loss Coefficient for each element of the building and identify weaknesses, which can be improved upon later.
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Ventilation is essential to maintain good air quality by removal of pollutants and excess moisture, thereby providing occupants with a healthy environment. In summer it plays an important role in cooling. Our next step will be to examine the ventilation strategies operating in the building - stack, single-sided and cross-ventilation - to calculate a suitable air exchange rate. Using meteorological data we will be able to make adjustments for wind velocity and direction, terrain and height, and time of year to find a Heat Loss Coefficient for ventilation. This information will enable us to identify ways in which ventilation can be manipulated to provide optimum user comfort by mechanical, natural and/or hybrid systems. As part of heat flow analysis we will need to take into account heat gains. We will calculate solar gain taking into consideration location, orientation, solar inclination and solar flux. It will also be necessary to factor in internal heat gains - heat from lighting, appliances and metabolic gains. To calculate energy use we need to identify our balance point - the external temperature above which a building needs no further heating to achieve a constant internal comfort temperature. We will do this using total heat loss derived from HLC fabric and HLC ventilation factored against temperature changes. Calculating degree-days we can then estimate the amount of time needed to heat our houses over a period of time. We can use this information to understand actual heating costs and assess ways in which they can be reduced. The final part of this investigation is to calculate energy use and carbon emissions. This will enable us to assess the building’s performance and benchmark it against current best and future practice.
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A comprehensive environmental study into a modern detached converted barn, located in Beaconsfield, Buckinghamshire.
Initial Building Analysis
The studied building was completed in 2010. Previously “the barn” was a large two-storey workshop for use within the family business until permission was granted to convert it into a family home. The detached house is orientated north with large front façade windows to optimize sunlight into the main spaces. There is a large front garden, which houses covered car parking spaces. The house is set back 26m from the busy Beaconsfield high street and A40 (leading into the M40). Prevailing winds come the SE largely blocked by trees and buildings creating a sheltered site. Studied site and building outlined below
• • • • •
The building is a traditional oak frame construction using QPA grade beam timber. The frame is connected through traditional joinery methods aided with steel joining hangers. The façade is clad in treated English oak. Thick butt mineral wool insulation was added during construction sealed with a layer of radiant barrier foil insulation. Minimal privacy issues exist due to large fences and the properties distance from the main high street. Privacy issues are further reduced through glazing specification of distorted glass on main façade windows. There are a large variety of window sizes ranging for small skylights to large façade dominating windows. All windows are double glazed high performance mullion style windows manufactured by Velux and Borecco. Shutters are all artificial fully controlled by the occupant. Average comfort temperature is 20’c controlled by CRC thermostats. Overheating is not common even in summer months, mainly due to orientation of the building. The least pleasurable space is the downstairs bedroom receiving minimal light at the rear of the building and having poor views.
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Ground Floor Average ceiling height: 3000mm Total floor area: 70.2 m2 3363
900,03
2082
2690
Entrance Lobby
Utility Room
1095
2082
Bathroom
1185
5720
1095
Kitchen
2789,38
3045
Bedroom 1
880
3880,81
Dining Room
3520
3750
920
1050
Comments: 1.1- Entrance Hall: The main entrance acts as a transitional space, minimising heat loss as the space externally exposed is limited. Used for storage of bikes and jackets. This creates a damp environment; this area is poorly ventilated, as there is no cross ventilation possibility. Thermostat for heating set at 20c . 1.2- Utility Room: Holds washing machine, tumble drier and the boiler (mega flow 750 electric boiler). Lack of windows creates a very dark space. REA electric panel provides heating for the house. 1.3- Bathroom: Downstairs bathroom no natural light, mechanically ventilated. If this breaks ventilation become very difficult. One radiator. 1.4- Kitchen and dining room: Very well lit and comfortable space two main radiators. Kitchen has a competent fan extractor above the cooker. Some heat escapes up stairwell, but the space never seems draughty. Oak wooden floors make the space feel colder. 1.5- Bedroom: Downstairs bedroom, two large windows lighting the space but neighbouring property construction blocks light. Bedroom is used intermittently due to corresponding to university breaks in winter and summer heating corresponds to this dates.
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First Floor Average ceiling height: 2100mm Total floor area: 50.69 m2 4080
3092,17
Bedroom 2
2341,44
Bathroom
WorkBench/ Office
4859,38
842
1766,95
2347,72
Living Room
1050
6090
Comments: 2.1-Living Area: Skylights create a nice cosy space emphasised been the eves. Contains a thermostat for house heating control. 2.2- Study/ Workshop: Desk overlooks the outside space. Toxic smells from paints and varnishes when working on antiques are ventilated naturally through opening the window. 2.3- Bathroom: Directly above downstairs bathroom ventilates mechanically with the same system as the below bathroom. Natural light comes through south facing skylight. 2.4- Bedroom: Main master bedroom, single or double occupant room that is well light and well heated throughout the year due to full time occupancy.
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Glazing Styles There are two different specifications of windows in the property for main composite wall windows and insulated roof skylights. • 5 Velux manufactured double glazed high performance centre pivot windows. • 9 Berecco argon filled double glazing units manufactured in a traditional mullion style. Tile batten Felt/breather membrane VELUX Transverse drainage gutter Support batten VELUX Underfelt collar BFX
A B
Installation batten VELUX Flashing EDW Top gutter
B
Vapour barrier
Internal finish
60
-1 5 25 0m m m m
A
Insulation
ELEVATION
SECTION A-A
Felt/breather membrane
80
20
m
m
m
m
VELUX Transverse drainage gutter VELUX Underfelt collar BFX
Gasket in window rebate Installation batten Chamfer VELUX Flashing EDW Pleated apron VELUX Underfelt collar BFX
VELUX Insulation frame BDX VELUX Vapour barrier BBX VELUX Lining LSB
Counter batten Felt/breather membrane
Purlin
VELUX Vapour barrier BBX
Sealed overlapping joint Vapour barrier
Energy Bill Observations The supply of energy comes (for planning reasons) come directly from the family shop located 20m away from the house. This energy is supplied ecotricity charged at 11.82p per KW/h. Energy bills are read off a separate energy meter in the house with an annual consumption is 6244 K/Wh per annum Hot Water system diagram The hot water/ heating system is supplied in a parallel circuit to radiators located under windows in key rooms.
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 Building Fabric Analysis
Wall construction The main wall structure is made of a thick traditional timber stud wall measuring 310mm including internal plasterboard. The remaining thickness of the wall is external battens and a profiled oak clad. Working out the thermal resistance of the wall component will allow me to calculate the U-Value and find out how the wall performs thermally. Wall Construction Detail Drawing (not to scale) 1 2
3
4a
Path 1
5
6a
Path 2
6b 4b
Path 3 Path 4
7
Path 5
8
9a 9b
10 11
Path 6 Path 7
Path 8
1. Rsi- Internal Air Surface 2. Fermnal Plaster Board 3. Fermnal Plaster Board 4a. Air Gap (service void) 4b. Softwood Timber Batterns 5. Vapour control area 6a. High Performance Mineral Wool 6b. Timber Stud 7. Softwood Weather Boarding 8. Corovin Breather Membrane 9a. Battern Air Space 9b. Timber Batterns 10. Oak Timber Cladding (sealed) 11. Rso- External Air Surface
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Composite Wall Structure
Thermal Resistance (m 2 K/W)
25
Thermal Conductivity (w/mK) 0.4
100 %
25
0.4
0.0625
Air Gap (service void)
92%
25
-
0.180
4b
Softwood Timber Batterns
8%
25
0.13
0.1923
5
Vapour Control Layer
100%
12
0.12
0.1
6a 6b 7
Mineral Wool Timber Studs Softwood Weather Boarding
95% 5% 100%
200 200 20
0.038 0.13 0.14
5.2631 1.5384 0.1428
8
Corovin Breather Membrane
100%
5
0.2
0.025
9a.
Timber Battern Airspace
67.5%
38
-
0.180
9b. 10. 11.
Timber Batterns Oak Cladding Rso
32.5% 100% 100%
38 15 -
0.13 0.18 -
0.2923 0.0833 0.040
Layer
Material
Proportion of Surface Area
Thickness (mm)
1 2
Rsi Plaster Board
100 %
3
Plaster Board
4a
0.12 0.0625
To work out a weighted U-Value for the wall we firstly identify possible thermal paths through the structure. The highlighted red numbers identify the calculation of possible thermal bridges. Calculation of upper resistance limit (Values taken from CIBSE Guid A, Calculated using equation 1) Path Fractional area of material surface layer, F 1 100 100 100 100 100 100 100 100
1 2 3 4 5 6 7 8
F/R Total 1/Total= Ruppe r
2 3 100 92 100 92 100 8 100 8 100 92 100 8 100 8 100 92 0.1749 5.7175m2K/W
4 100 100 100 100 100 100 100 100
5 95 5 95 95 95 5 5 5
6 100 100 100 100 100 100 100 100
7 100 100 100 100 100 100 100 100
8 67.5 67.5 67.5 32.5 32.5 67.5 32.5 32.5
9 100 100 100 100 100 100 100 100
F total
Total resistance R
F/R
0.5899 0.0310 0.0513 0.0247 0.2840 0.0027 0.0013 0.0149
6.2592 2.5345 6.2715 6.3435 6.3715 2.5468 2.4913 2.6465
0.0942 0.0122 0.0082 0.0039 0.0445 0.0011 0.0052 0.0056
Lower Resistance Limit After the upper resistance limit is calculated the lower resistance limit is calculated using the “equation 2” Layer
Fractional Area, F
Thermal resistance per path, R (m2K/W)
F/R
Total F/R
1/Total F/R (m 2 K/W)
4a 4b
92 8
0.180 0.1923
5.111 0.4161
5.5271
0.1809
6a 6b
95 5
5.2631 1.5384
0.1805 0.325
0.5055
1.9782
9a 9b
67.5
3.75 1.1119
4.8619
0.2056
0.180 32.5
0.2923
Rlower is equal to the total of all the resistances in the cut section. Layer Material Thermal Resistance (m2K/W) Rsi 0.12 1 Plaster Board 0.0625 2 Plaster Board 0.0625 3 Timber Batterns and Air Void 0.1809 4 Vapour Control Layer 0.1 5 Mineral Wool Insulation & Timber studs 1.9782 6 Softwood Weather Boarding 0.1428 7 Corovin Breather Membrane 0.025 8 Timber batterns & airspace 0.2056 9 Oak Cladding 0.0833 10 Rso 0.040 11 Rtotal
3.0008
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Calculating The Total U-Value for Composite Wall Rupper= 5.7175 Rlower= 3.0008 Rtotal equation = 5.7175+3.0008/2 Rtotal= 4.3591 U Value = 1/ 4.3591 U-Value = 0.2294 The U-Value of 0.2294 shows good thermal performance of the wall structure. However within the nature traditional timber structure builds large amounts of thermal bridging occur pushing up the wall U-Value compared to that if there were only one homogenous thermal path through the structure assuming no thermal bridging When working out the homogenous value = Rtotal of path 1 = 6.2592 U Value= 1/Rtotal =1/6.2592 =0.1598 considerably lower than the bridged construction value, which would fall into passiv haus guidelines however in reality the value is unrealistic. Ceiling and Roof Analysis The barn construction typology means all first floor space is under an insulated pitched roof. As all elements of the wall construction are all incorporated the structure, the U-Value is calculated as a non-homogenous layer. Not to scale
Rsi Plaster Board Rafter Mineral Wool Insulation
Bitumen Sarking Felt Vertical Batten Horizontal Batten Clay Tiles Ventilated Void Rso
Integrated Pitched Insulated Roof becomes fully ventilated above the bitumen sarking felt. Illustrated by this line. A Rso for still air is used to calculate the U-Value for this section
Roof Structure Plan Cutaway
Path 1
Path 2
1
2
3a
4
5
3b
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Insulated Pitched Roof Specification Layer
Material
Proportion of surface area
Thickness (mm)
1 2 3a 3b 4 5
Rsi Plasterboard Mineral Wool Insulation Oak Rafter Bitumen Sarking Felt Rso (still air)
100% 100% 76% 24% 100% 100%
50 250 250 35 -
Thermal Conductivity (W/mK) 0.4 0.038 0.18 0.19 -
Thermal Resistance, R (m 2 K/W) 0.1 0.125 6.5789 1.3888 0.1842 0.4
Calculating Upper Resistance Limit (Values taken from OBSE Guide A, calculated using equation 1) Path Fractional area of material surface layer, F
1 2
1 100 100
2 100 100 0.212 4.7169
F/R Total 1/Total= Ruppe r
3 76 24
4 100 100
5 100 100
F total
Total resistance R
F/R
0.76 0.24
7.3881 2.198
0.1029 0.1091
Calculating Lower Resistance Limit (Calculated using equation 2) Layer Fractional Area, F Thermal resistance per path, R (m2K/W) 3a 76 6.5789 3b 24 1.3888
F/R 0.0116 0.0173
Total F/R 0.0289
1/Total =Rlowe r (m 2 K/W) 3.4602
Rlower is equal to the total of all the resistances in the cut section. Layer 1 2 3 4 5 Rtotal
Thermal Resistance (m 2 K/W) 0.1 0.125 3.4602 0.1842 0.4
Material Rsi Plaster Board Mineral Wool and Rafters Bitumen Sarking Felt Rso (still air 4.2694
Calculating U-Value Rtotal = Rupper + Rlower / 2 = 4.7169 + 4.2694 / 2 = 4.4932 Rtotal U-Value = 1/ Rtotal = 1/ 4.4932 U-Value= 0.223 The roof structure has a very a low U-value. The large amount of insulation is responsible for this coupled with less thermal bridging within the structure. Compared to the wall structure the roof has slightly lower U-Value. However both U-Values are relatively low and considered OK under SAP guidelines and will do a good job in reducing carbon emissions from the building. Windows (external wall and skylight) Window Type Velux Roof Skylight Berecco Mullion Window
No. in Property 5 9
Thermal Resistance (m 2 K/W) 0.9
U-Value =1/Rtotal (W/m2K) 1.4 1.111
All Bereco products are designed with 24mm double- glazed soft-coated glazing units. Low E argon filled float glass comes standard. Ground Floor (All floor calculations using equation 4) Perimeter (m) Area (m 2 ) 34.756 70.2
First Floor
Perimeter (m) 22.936
P/A (m/m 2 ) 0.495
Area (m2) 47.84
U-Value(W/m 2 K)-
Thermal Resistance (m 2 K/W) 1.5 0.32
U-Value(W/m2K)-
Thermal Resistance (m 2 K/W) 2 0.27
P/A (m/m2) 0.479
Openings & Doors Quoted from timber frame design specification, English heritage homes LTD. U-Value Openings Oak Framed Doors
1.96 1.32
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Geometric Bridging To complete the calculation of the total HLC for the dwelling the sum of all geometrical bridges needs to be calculated. Ground Floor Front North 1 Floor Ceiling Corners Front East 2 Floor Ceiling Corners Front North 3 Floor Ceiling Corners Side East 4 Floor Ceiling Corners Back South 5 Floor Ceiling Corners Side West 6 Floor Ceiling Corners
Linear Transmittance ϕ
Length of bridge L (mm)
(Lx ϕ linear thermal transmittance)
0.16 0.07 0.09
7270 7270 3000
1.163 0.508 0.27
0.08 0.07 0.09
1200 1200 3000
0.096 0.084 0.27
0.16 0.07 0.09
2890 2890 3000
0.462 0.202 0.27
0.16 0.07 0.09
4030 4030 3000
0.645 0.301 0.27
0.16 0.07 0.09
9851 9851 3000
1.577 0.689 0.27
0.16 0.07 0.09
7305 7305 3000
1.168 0.511 0.27 Total Ground Floor Htb
First Floor Front North 1 Intermediate Floor Eaves Rafter Insulated Corners Front East 2 Intermediate Floor Eaves Rafter Insulated Corners Front North 3 Intermediate Floor Eaves Rafter Insulated Corners Side East 4 Intermediate Floor Eaves Rafter Insulated Corners Back South 5 Intermediate Floor Eaves Rafter Insulated Corners Side West 6 Intermediate Floor Eaves Rafter Insulated Corners
9.026
Linear Transmittance ϕ
Length of bridge L (mm)
(Lx ϕ linear thermal transmittance)
0.07 0.04 0.09
7270 7270 2100
0.508 0.291 0.189
0.07 0.04 0.09
1200 1200 2100
0.084 0.048 0.189
0.07 0.04 0.09
2890 2890 2100
0.202 0.116 0.189
0.07 0.04 0.09
4030 4030 2100
0.282 0.161 0.189
0.07 0.04 0.09
9851 9851 2100
0.689 0.394 0.189
0.07 0.04 0.09
7305 7305 2100
0.511 0.292 0.189 Total First Floor Htb
4.712 Total Htb = 13.738
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Heat Loss Coefficient- Fabric (Calculated using equation 5) U-Value (Wm 2 /K) Ground Floor 0.32 First Floor 0.27 Wall 0.2294 First Floor Walls 0.2294 Roof 0.223 Berecco Windows 1.111 Velux Skylights 1.4 Doors 1.32
Area (m 2 ) 70.2 47.84 104 25.76 87.72 12.04 1.65 2.25
HLC (UxA) (W/K) 22.47 12.92 23.86 5.91 19.56 13.24 2.31 2.97
Heat lose geometric bridging 5.11 2.276 1.62 1.134 1.302 -
HLC total (W/K) 27.58 15.196 25.48 7.044 20.862 13.24 2.31 2.97 HLC fabric total=114.682
Building Fabric Analysis
160 140 120 100 80
HLc (W/K)
60
Area m2
40 20 0 Floor
Wall
Roof
Brecco Velux Windows Skyights
Doors
The graph compares the area of each component relative to the HLC. The graph shows that the building fabric is performing very well relative to the areas of the spaces. Perhaps the most successful element of the construction is the roof. The roof structure in timber frame is usually very susceptible to large heat loss through bridging but in the case the successful design of a modern timber frame structure has prevented this from occurred and a super insulation strategy within the fabric has worked well. The calculated U-Values for the fabric are low compared to the majority of buildings but fall short of passiv house guidelines. With the implication of interior insulation plasterboard the value may fall into passiv haus guidelines. The attempted reduction in U-Value through two layers of plasterboard was relatively unsuccessful compared alternative options available. However when the cost of such design implication is calculated, it may not be worth the about of energy consumption saved. These low HLC values so the relatively easy successful implication of eco friendly timber frame structures.
Ventilation Analysis
Ventilation plays key part in any buildings occupant success. Successful ventilation maintains healthy air quality for all occupants through the recycling of oxygen, its removes pollutants, condensation and importantly during hotter periods ventilation is the main component in cooling the building to a desired comfort temperature. Building regulations state there must be a minimum ventilation rate of 0.3l/s per m2 for domestic dwellings. Table 5.1b(part F of building regulations) states that the suggested SASR (l/s pers) for a two-bedroom dwelling is 17 l/s pers. Using a minimum ventilation rate of 0.3l/s factoring in the size of the dwelling a SASR of 27.4215 l/s is calculated. Volume flow rate is based on the number of occupants in the dwelling. In this case 3 occupants are used in the calculation using q= N x SASR/1000. Volume flow rate= 0.0823m3/s This air exchange rate can then be calculated from the volume flow rate using the calculation; n=q x 3600/ v Air exchange rate (arch-1) =1.344 arch-1 Knowing the minimum air exchange rate within the dwelling it is possible to calculate the HLCventilation for the dwelling using the equation; HLCventilation= 1/3 x n x v HLC ventilation = 1/3 x 1.344 x 220.49 HLCventilation = 98.779 w/k
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HLC for heating months (September-May) For heating months it is assumed that the majority of windows leading to wind driven ventilation will be closed. As a result a low air exchange rate is used in HLCventilation calculations. Each room’s volume is taken into consideration and a total HLC for ventilation during this period is calculated. For mechanically ventilated spaces such as bathrooms and the utility room an air exchange rate is calculated using data tables from (Szokolay introduction to architectural science.) (Calculated using equation 10) Ach- 1 1.344 1.344 2.6 1.344 2.6 1.344 1.344 2.6 2
Kitchen/Dining Room Entrance Hall Utility Room Bedroom Downstairs Downstairs Bathroom Living Room Bedroom 2 Upstairs Bathroom Hallway/Stairs
Vm 3 61.776 27.643 17.114 40.973 25.437 68.344 27.754 9.095 17.16
HLC (W/K) 27.676 12.384 14.832 18.356 22.045 30.618 12.434 7.8823 11.44 HLC Total = 157.6673
HLCventilation = 1/3 x n x v Meteorological Data Correction Cooling Months (June-August) To analyse a building’s ventilation within the cooling months meteorological data must be corrected for the calculations. Calculating a corrected wind speed value taking into consideration building height, air viscosity, surface roughness and average wind speeds allows us to achieve more accurate air exchange rate and subsequent HLC values. This is calculated through V z or r = V m x K x Z a All ventilation calculations taken for the cooling period show maximum ventilation rates using values for all windows, and at maximum opening.
Summer
Winter
(Calculated using equation 13) Month Wind Angle Deg June 270 July 270 August 270
Wind Speed (km/h) 16.668 18.504 16.668
Wind Speed (knots) 9 10 9
Wind Speed ms-1 4.63 5.14 4.63
Velocity corrected for the terrain and height of building; June July August
Vm 4.63 5.14 4.63
K(cp) 0.35 0.35 0.35
Za 5.5 5.5 5.5
0.25 0.25 0.25
Vr 2.482 2.755 2.482
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Single Sided Ventilation- June & August (Using Equations 9,10,11) Room
Window
Kitchen Dining Room Lobby Bedroom
A B C A A B A
Hall/ Stairs
Effective Width (m) 1.03 1.03 1.1 0.903 0.82 1.05 0.88
Height (m) 0.3 0.3 0.6 0.92 0.7 0.8 0.3
True Area (m 2 ) 0.309 0.309 0.66 0.856 0.574 0.84 0.264
Compound Coefficient
0.025
Vr
Q wind
2.482
0.019 0.019 0.041 0.053 0.036 0.052 0.016
Arch- 1
Q wind per room 0.079
Volume (m 3 ) 61.776
4.604
HLC (W/K) 94.80
0.053 0.088
27.643 40.973
6.902 7.732
63.59 105.6
0.016
17.16
3.356
19.19
Total HLC = 283.18 W/K
Single Sided Ventilation-July (Using Equations 9,10,11) Room
Window
Kitchen Dining Room Lobby Bedroom
A B C A A B A
Hall/ Stairs
Effective Width (m) 1.03 1.03 1.1 0.903 0.82 1.05 0.88
Height (m) 0.3 0.3 0.6 0.92 0.7 0.8 0.3
True Area (m 2 ) 0.309 0.309 0.66 0.856 0.574 0.84 0.264
Compound Coefficient
0.025
Vr
Q wind
2.755
0.021 0.021 0.045 0.059 0.039 0.057 0.018
Arch- 1
Q wind per room 0.087
Volume (m 3 ) 61.776
5.069
HLC (W/K) 104.4
0.059 0.096
27.643 40.973
7.684 8.435
70.81 115.2
0.018
17.16
3.776
21.59
Total HLC = 312 W/K
HLC –June & August = 283.18 W/K HLC- July = 312 W/K Cross Ventilation First Floor June-August For cross ventilation purposes the V r between June-August has been averaged and then calculated assuming the illustrated cross ventilation paths with a predominant south facing wind direction.
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Living Space (Calculated using equations 10, 18 & 19)
Cd
0.6
Aw Vr Cp Cp 0.5 Volume m3
0.1967 2.6185 0.3 0.54772 68.344
Qwind Ach -1 HLC W/K
0.1693 8.9178 203.159
Total Opening Area Area 2 1/Area Total 1/Total Sq root
A1 0.228 x 3= 0.684
A2 0.144 X 2 =0.288
0.467 2.141 25.824 0.0387 0.1967
0.0829 12.062
A1
A2 0.228
Bedroom Upstairs (Calculated using equations 10, 18 & 19)
Cd
0.6
Aw Vr Cp Cp 0.5 Volume m3
0.2176 2.6185 0.3 0.54772 27.754
Qwind Ach -1 HLC W/K
0.18724 24.287 224.687
Total Opening Area Area 2 1/Area Total 1/Total Sq root
0.735
0.5402 1.8512 21.1182 0.04735 0.2176
0.0519 19.267
Heat Loss Co-efficient Total Heating Period( September- May) 157.6673
Cooling Period (June & August) 711.026
Cooling Period (June & August) Corrected 355.513
Cooling Period (June & August) Corrected 739.846
Cooling Period (July) Corrected 369.923
All of the calculations for the cooling period assume that all of the windows are open, for the whole period of each analysed month. As a result this produces an extreme situation HLC (maximum value). In reality the window opening will depend on where the occupant is located. i.e. when you occupy a space you control the ventilation through the opening of windows this tends to be restricted to only the space you currently occupy. As a result of this the cooling HLC is overstated an estimation value of 346.468 is given taking a 50% reduction in the HLC total (this is still a very high value for the occupant behaviour in my home.) This dramatically affects the average HLC ventilation and will have the resultant effect of overstating the energy consumption in the building.
Solar Gains
For solar gain analysis all 4 facades were taken as illustrated below;
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Values for Svertical were calculated on the 4 illustrated facades using the spreadsheet. (converting horizontal to vertical flux) Representative Latitude (.N) 51.5
Buildings Latitude (.N) 51.6
Solar Radiation on the Horizontal (W/m2) June July
August
214
177
204
(Calculations using equation 16) Façade North 0. Façade East -90. Month Svertical Month Svertical (m) W/m 2 (m) W/m 2 Jan 10.72641674 Jan 19.87256466 Feb 20.35879704 Feb 38.51867736 March 33.30872704 March 61.56524736 April 54.639576 April 91.409784 May 75.2159916 May 111.2196844 June 91.97853536 June 122.9558742 July 85.34413644 July 117.784192 Aug 67.65654372 Aug 104.9219255 Sep 41.085141 Sep 73.603769 Oct 24.81434852 Oct 46.90850868 Nov 13.21801668 Nov 24.70675812 Dec 8.94448464 Dec 16.39290576
Façade South -180. Month Svertical (m) W/m 2 Jan 47.3233189 Feb 77.1832044 March 94.2460544 April 105.11436 May 108.549926 June 114.5726896 July 110.5232934 Aug 107.4132542 Sep 99.990985 Oct 85.2918322 Nov 56.0693298 Dec 40.8904104
Calculations using values from CIBSE Guide A, table 6b & 6d Solar Solar access Façade Transmittance Winter
Façade West 90. Month Svertical (m) W/m 2 Jan 19.87256466 Feb 38.51867736 March 61.56524736 April 91.409784 May 111.2196844 June 122.9558742 July 117.784192 Aug 104.9219255 Sep 73.603769 Oct 46.90850868 Nov 24.70675812 Dec 16.39290576
Solar Access Summer
Opening Area(m)
Frame Factor
Kitchen.1
N
0.63
1
1
0.876
0.7
Kitchen.2 Dining Room.1
N
0.63
1
1
0.876
0.7
N
0.63
1
1
2.9625
0.7
Hallway.1
N
0.63
0.77
0.9
1.936
0.7
Hallway.2
S
0.63
0.54
0.7
0.228
0.7
Lobby.1 Living Room.1 Living Room.2 Living Room.3 Living Room.4
N
0.63
0.3
0.5
1.08
0.7
N
0.63
1
1
0.9262
0.7
N
0.63
1
1
0.3976
0.7
N
0.63
1
1
0.3976
0.7
S
0.63
1
1
0.228
0.7
Bathroom.1
S
0.63
1
1
0.228
0.7
Bedroom.1
W
0.63
0.54
0.7
1.104
0.7
Bedroom.2
W
0.63
0.3
0.5
1.26
0.7
Bedroom.3.
S
0.63
1
1
0.228
0.7
Bedroom.4
E
0.63
0.3
0.5
1.2
0.7
Ground Floor Solar Calculations (Heating Period) (Calculated using the spreadsheet “Calculating solar gains”.) Jan Feb March April May Sep Oct Nov Dec
Kitchen.1
Kitchen.2
Dining Room.1
Hallway.1
Hallway.2
Lobby.1
Bedroom.1
Bedroom.2
3.729407768
3.729407768
12.61229511
6.346464325
2.312516823
1.379369997
4.702164852
2.981445105
7.078436134
7.078436134
23.93820439
12.04562365
3.771659782
2.618051721
9.114131664
5.778887831
11.58092478
11.58092478
39.16494252
19.70766687
4.605458607
4.283355739
14.56731666
9.236523244
18.9973282
18.9973282
64.24610135
32.32842134
5.136552793
7.026409059
21.62900868
13.71404536
26.15142691
26.15142691
88.44018518
44.50280265
5.304436288
9.672445569
26.31634617
16.68608906
14.2846626
14.2846626
48.30857642
24.30871259
4.88619227
5.283368358
17.41582234
11.04264098
8.627561877
8.627561877
29.17711422
14.68182539
4.167898648
3.191016037
11.09929919
7.037599122
4.595698199
4.595698199
15.54195881
7.820661208
2.739902261
1.699778786
5.846011907
3.706710449
3.109857775
3.109857775
10.51707039
5.292154318
1.998164207
1.150221369
3.878822216
2.459398144
77
First Floor Solar Calculation (Heating Period) (Calculated using the spreadsheet “Calculating solar gains”.) Living Room.1 Jan Feb March April May Sep Oct Nov Dec
Jan Feb March April May Sep Oct Nov Dec
Living Room.2
Living Room.3
Living Room.4
Bathroom.1
Bedroom.3
Bedroom.4
3.943124972
1.692708366
1.692708366
7.467971808
7.467971808
4.282438562
6.761745098
7.484072542
3.212769642
3.212769642
12.1800839
12.1800839
6.984555152
11.02824498
12.24458051
5.256364944
5.256364944
14.87272857
14.87272857
8.52862705
13.46625324
20.08598787
8.622531611
8.622531611
16.58782806
16.58782806
9.512134802
15.01916021
27.65005891
11.86964308
11.86964308
17.12998593
17.12998593
9.823030164
15.51004763
15.10325856
6.483540923
6.483540923
15.77932137
15.77932137
9.048504204
14.2871119
9.121972386
3.915888815
3.915888815
13.45968569
13.45968569
7.71833083
12.18683815
4.859058986
2.085901374
2.085901374
8.848157398
8.848157398
5.073893075
8.011410119
3.288071086
1.411506223
1.411506223
6.452810986
6.452810986
3.700304086
5.8425854
Total Downstairs
Total Upstairs
Total Qsolar (Heating Period)
37.79307175
33.30866898
71.10174073
71.4234313
56.28257975
127.7060111
114.7271132
74.49764784
189.224761
182.075195
95.03800223
277.1131972
243.2251587
110.9823947
354.2075535
139.8146381
82.96459924
222.7792374
86.60987636
63.77829038
150.3881667
46.54641981
39.81247973
86.35889954
31.51554619
28.55959499
60.07514118 Q solar (w) 1538.954708
Ground Floor Calculations (Cooling period) (Calculated using the spreadsheet “Calculating solar gains”.) Dining Kitchen.1 Kitchen.2 Room.1 Hallway.1 June 31.97950188 31.97950188 108.1498565 63.60854346 July 29.67282487 29.67282487 100.3490225 59.0204681 Aug 23.52312481 23.52312481 79.55166352 46.78846195
Hallway.2
Lobby.1
Bedroom.1
Bedroom.2
7.25763452
19.71339157
37.71355692
30.74474749
7.001124546
18.29146739
36.12727619
29.45158385
6.804118366
14.50055639
32.18210625
26.2354127
First Floor Calculations (Cooling Period) (Calculated using the spreadsheet “Calculating solar gains”.) Living Living Living Room.1 Room.2 Room.3 June 33.81211717 14.5148972 14.5148972 July 31.37325388 13.46793969 13.46793969 Aug 24.8711395 10.67670596 10.67670596
Living Room.4
Bathroom.1
Bedroom.3
Bedroom.4
18.08042284
18.08042284
10.36804931
29.28071188
17.44139799
17.44139799
10.00160649
28.04912748
16.95061067
16.95061067
9.720169095
24.98610734
Total Qsolar totals (cooling periods) June July Aug
Total Downstairs
Total Upstairs
Total Q solar (cooling period)
331.1467342
138.6515184
469.7982527
309.5865923
131.2426632
440.8292555
253.1085688
114.8320492
367.940618 Total Qsolar (w)- 1278.568126
Â
78
Monthly Solar Gain Per Room 120
100 Jan Feb 80
March April May
60
June July Aug
40
Sep Oct Nov
20
Dec
0 Kitchen
Dining Room
Hallway
Lobby
Bedroom Living Room Bathroom
Bedroom
Solar gains in general are quite low this is due to predominately north facing aspect of windows. Where windows are exposed to south facing aspect the area of exposed window is small such as with skylights thus producing the low solar gain figure.
Internal Heat Gains
Lighting Gains A yearly for the lighting time has been taken to accommodate for the more intense use in winter than in summer. (Calculations using equations 14) Light Type
No.fittings
Power (w)
Total power (w)
Time (s)
Energy (J)
1
20
20
1800
36000
Utility Room
Spiral 100w eq. GU10 compact flourescent
3
7
21
360
7560
Kitchen
GU10 Halogen
5
50
250
7200
1800000
Dining Room
Spiral 60w eq.
2
11
22
21600
475200
Bathroom 1
GU10 Halogen GU10 compact flourescent GU10 compact flourescent
1
50
50
100
5000
3
7
21
200
4200
4
7
28
3600
100800
Spiral 60w eq. GU10 compact flourescent
2
11
22
28800
633600
4
7
28
14400
403200
2
50
100
14400
1440000
Bathroom 2
GU10 Halogen GU10 compact flourescent
2
7
14
2880
40320
Bedroom 2
Spiral 100w eq.
1
20
20
7200
144000
Lobby
Bedroom 1 Hallway Living Room Study
Total Energy (J) Q lighting (w)
5089880 58.910648
Appliance Gains (Calculations using equations 14, based on data provided by manufacturers where available) Kitchen
Appliance
Power (w)
Time (s)
Oven
1200
7200
Energy (J) 8640000
Fridge/freezer
500
86400
43200000
Dishwasher
1200
3600
4320000
Microwave
1000
300
300000
Kettle
3000
500
1500000
Â
Â
79 Bathroom 1 Bedroom 1 Lving Room
Study Bathroom 2 Bedroom 2
Utility Room
Hairdryer
1200
100
120000
Power Shower
240
420
100800
LED TV
80
900
72000
Laptop
30
10800
324000
LED TV
240
7200
1728000
Sky Box
50
86400
4320000
Ipod Speakers
60
900
54000
Desktop Computer
130
18000
2340000
Magnifying glass
50
3600
180000
Hairdrier
1200
100
120000
Power Shower
240
2800
672000
LED TV
240
3600
864000
Laptop
60
14400
864000
Speakers
100
200
20000
Washing Machine
500
1800
900000
Tumble Drier
4000
500
2000000
Total Energy
72638800
Q appliance (w)
840.7266
Metabolic Gains
(Calculations using equations 14) Occupant
Gain (W)
Time (S)
Metabolic Energy (J)
Male
115
21600
2484000
140
3600
504000
115
7200
828000
140
1800
252000
97.75
16200
1583550
Total Energy
5651550
Male Female
Q me tabolic (W) 65.411458
Internal Gain Analysis Total Q lighting (W)
58.910648
Q appliance (w)
840.7266
Q me tabolic (w)
65.411458
Q inte rnal (W)
965.048706
The large number of energy saving light bulbs has created a low Qlighting. This figure has been bought up dramatically by GU10 haolgen light bulbs in areas such as the kitchen accounting for just over 20% of the total Qlighting value, this suggested their immediate replacement with low energy equivalents. Despite our best efforts to maintain and eco friendly home the main energy consumption is coming from appliance use within the house, this figure being almost 15x large than Qlighting. Although low energy appliances are difficult to source and very expensive to replace, comparative to bulbs, our energy consumption could be greatly reduced by simple spending less time on these appliances. Due to the busy nature of the house the Qmetabolic is relatively low, the relatively small spaces within the dwelling are larger affected by metabolic gains especially in the living room. In reality this metabolic gain will be considerably lower as the student occupant lives there for under half a year when not at university.
Â
80
Balance Points
Heating Period (September-May) (Calculations using equation 12) To
Ti
Delta T
HLC (W/K)
Q total heat loss
-1
21
22
272.3493
5991.6846
Month Jan
-0.5
21
21.5
272.3493
5855.50995
Feb
0
21
21
272.3493
5719.3353
0.5
21
20.5
272.3493
5583.16065
1
21
20
272.3493
5446.986
March April
1.5
21
19.5
272.3493
5310.81135
May
2
21
19
272.3493
5174.6367
June
2.5
21
18.5
272.3493
5038.46205
3
21
18
272.3493
4902.2874
July
3.5
21
17.5
272.3493
4766.11275
Aug
4
21
17
272.3493
4629.9381
Sep
4.5
21
16.5
272.3493
4493.76345
Oct
5
21
16
272.3493
4357.5888
Nov
5.5
21
15.5
272.3493
4221.41415
6
21
15
272.3493
4085.2395
6.5
21
14.5
272.3493
3949.06485
7
21
14
272.3493
3812.8902
7.5
21
13.5
272.3493
3676.71555
8
21
13
272.3493
3540.5409
8.5
21
12.5
272.3493
3404.36625
9
21
12
272.3493
3268.1916
9.5
21
11.5
272.3493
3132.01695
10
21
11
272.3493
2995.8423
10.5
21
10.5
272.3493
2859.66765
11
21
10
272.3493
2723.493
11.5
21
9.5
272.3493
2587.31835
12
21
9
272.3493
2451.1437
12.5
21
8.5
272.3493
2314.96905
13
21
8
272.3493
2178.7944
13.5
21
7.5
272.3493
2042.61975
14
21
7
272.3493
1906.4451
14.5
21
6.5
272.3493
1770.27045
15
21
6
272.3493
1634.0958
15.5
21
5.5
272.3493
1497.92115
16
21
5
272.3493
1361.7465
16.5
21
4.5
272.3493
1225.57185
17
21
4
272.3493
1089.3972
17.5
21
3.5
272.3493
953.22255
18
21
3
272.3493
817.0479
18.5
21
2.5
272.3493
680.87325
19
21
2
272.3493
544.6986
19.5
21
1.5
272.3493
408.52395
20
21
1
272.3493
272.3493
20.5
21
0.5
272.3493
136.17465
21
21
0
272.3493
0
Dec
Qsolar
Qinternal
Qtotal Heat gain
71.10174073
965.048706
1036.150447
127.7060111
965.048706
1092.754717
189.224761
965.048706
1154.273467
277.1131972
965.048706
1242.161903
354.2075535
965.048706
1319.25626
469.7982527
965.048706
1382.286565
440.8292555
965.048706
1356.140525
367.940618
965.048706
1291.386994
222.7792374
965.048706
1187.827943
150.3881667
965.048706
1115.436873
86.35889954
965.048706
1051.407606
60.07514118
965.048706
1025.123847
81
Heating Period Monthly Balance Points (September – May) -1.00
Q total
Jan
Feb
March
April
May
Sep
Oct
Nov
Dec
5991.68
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
-0.50
5855.51
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
0.00
5719.34
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
0.50
5583.16
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
1.00
5446.99
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
1.50
5310.81
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
2.00
5174.64
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
2.50
5038.46
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
3.00
4902.29
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
3.50
4766.11
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
4.00
4629.94
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
4.50
4493.76
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
5.00
4357.59
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
5.50
4221.41
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
6.00
4085.24
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
6.50
3949.06
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
7.00
3812.89
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
7.50
3676.72
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
8.00
3540.54
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
8.50
3404.37
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
9.00
3268.19
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
9.50
3132.02
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
10.00
2995.84
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
10.50
2859.67
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
11.00
2723.49
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
11.50
2587.32
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
12.00
2451.14
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
12.50
2314.97
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
13.00
2178.79
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
13.50
2042.62
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
14.00
1906.45
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
14.50
1770.27
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
15.00
1634.10
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
15.50
1497.92
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
16.00
1361.75
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
16.50
1225.57
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
17.00
1089.40
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
17.50
953.22
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
18.00
817.05
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
18.50
680.87
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
19.00
544.70
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
19.50
408.52
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
20.00
272.35
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
20.50
136.17
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
21.00
0.00
1036.15
1092.75
1092.75
1242.16
1319.26
1187.83
1115.44
1051.41
1025.12
16.21
16.11
16.34
16.48
17.16
17.29
Balance Point c 17.22 16.89 16.51 Balance points read off graph below through excel
82
Balance Point Heating Period 7000.000
6000.000
5000.000
Qtotal Heat Loss Jan Feb
4000.000
March April May June July Aug
3000.000
Sep Oct Nov Dec
2000.000
1000.000
0.000 -10
0
10
20
30
40
50
83
Â
Cooling Period (June & August)
Due to the dramatic changes in HLC between heating and cooling months, HLC incorporates a maximum HLC ve ntilation value as the taken ventilation flow rates were calculated assuming all windows fully open 50% of the time (although reduced from 100% this figure is overstated) (Calculations using equation 12) To
Ti
Delta T
HLC (W/K)
Q total heat loss
-1
21
22
470.195
10344.29
Month June
-0.5
21
21.5
470.195
10109.1925
July
0
21
21
470.195
9874.095
0.5
21
20.5
470.195
9638.9975
Aug
1
21
20
470.195
9403.9
1.5
21
19.5
470.195
9168.8025
2
21
19
470.195
8933.705
2.5
21
18.5
470.195
8698.6075
3
21
18
470.195
8463.51
3.5
21
17.5
470.195
8228.4125
4
21
17
470.195
7993.315
4.5
21
16.5
470.195
7758.2175
5
21
16
470.195
7523.12
5.5
21
15.5
470.195
7288.0225
6
21
15
470.195
7052.925
6.5
21
14.5
470.195
6817.8275
7
21
14
470.195
6582.73
7.5
21
13.5
470.195
6347.6325
8
21
13
470.195
6112.535
8.5
21
12.5
470.195
5877.4375
9
21
12
470.195
5642.34
9.5
21
11.5
470.195
5407.2425
10
21
11
470.195
5172.145
10.5
21
10.5
470.195
4937.0475
11
21
10
470.195
4701.95
11.5
21
9.5
470.195
4466.8525
12
21
9
470.195
4231.755
12.5
21
8.5
470.195
3996.6575
13
21
8
470.195
3761.56
13.5
21
7.5
470.195
3526.4625
14
21
7
470.195
3291.365
14.5
21
6.5
470.195
3056.2675
15
21
6
470.195
2821.17
15.5
21
5.5
470.195
2586.0725
16
21
5
470.195
2350.975
16.5
21
4.5
470.195
2115.8775
17
21
4
470.195
1880.78
17.5
21
3.5
470.195
1645.6825
18
21
3
470.195
1410.585
18.5
21
2.5
470.195
1175.4875
19
21
2
470.195
940.39
19.5
21
1.5
470.195
705.2925
20
21
1
470.195
470.195
20.5
21
0.5
470.195
235.0975
21
21
0
470.195
0
Qsolar
Qinternal
Qtotal Heat gain
469.7982527
965.048706
1382.286565
440.8292555
965.048706
1356.140525
367.940618
965.048706
1291.386994
Â
84
Monthly Balance Points Cooling Period (June & August) Q total
June
August
-1.000
10344.29
1382.286565
1291.386994
-0.500
10109.1925
1382.286565
1291.386994
0.000
9874.095
1382.286565
1291.386994
0.500
9638.9975
1382.286565
1291.386994
1.000
9403.9
1382.286565
1291.386994
1.500
9168.8025
1382.286565
1291.386994
2.000
8933.705
1382.286565
1291.386994
2.500
8698.6075
1382.286565
1291.386994
3.000
8463.51
1382.286565
1291.386994
3.500
8228.4125
1382.286565
1291.386994
4.000
7993.315
1382.286565
1291.386994
4.500
7758.2175
1382.286565
1291.386994
5.000
7523.12
1382.286565
1291.386994
5.500
7288.0225
1382.286565
1291.386994
6.000
7052.925
1382.286565
1291.386994
6.500
6817.8275
1382.286565
1291.386994
7.000
6582.73
1382.286565
1291.386994
7.500
6347.6325
1382.286565
1291.386994
8.000
6112.535
1382.286565
1291.386994
8.500
5877.4375
1382.286565
1291.386994
9.000
5642.34
1382.286565
1291.386994
9.500
5407.2425
1382.286565
1291.386994
10.000
5172.145
1382.286565
1291.386994
10.500
4937.0475
1382.286565
1291.386994
11.000
4701.95
1382.286565
1291.386994
11.500
4466.8525
1382.286565
1291.386994
12.000
4231.755
1382.286565
1291.386994
12.500
3996.6575
1382.286565
1291.386994
13.000
3761.56
1382.286565
1291.386994
13.500
3526.4625
1382.286565
1291.386994
14.000
3291.365
1382.286565
1291.386994
14.500
3056.2675
1382.286565
1291.386994
15.000
2821.17
1382.286565
1291.386994
15.500
2586.0725
1382.286565
1291.386994
16.000
2350.975
1382.286565
1291.386994
16.500
2115.8775
1382.286565
1291.386994
17.000
1880.78
1382.286565
1291.386994
17.500
1645.6825
1382.286565
1291.386994
18.000
1410.585
1382.286565
1291.386994
18.500
1175.4875
1382.286565
1291.386994
19.000
940.39
1382.286565
1291.386994
19.500
705.2925
1382.286565
1291.386994
20.000
470.195
1382.286565
1291.386994
20.500
235.0975
1382.286565
1291.386994
21.000
0
1382.286565
1291.386994
Balance Point c 18.11 Balance points read off graph below through excel
18.24
85
Balance Point Cooling Period (June & August) 12000
10000
8000
Qtotal
6000
June August
4000
2000
0 -5
0
5
10
15
20
25
86
Cooling Period (July)
(Calculations using equation 12) To
Ti
Delta T
HLC (W/K)
Q total heat loss
-1
21
22
369.923
8138.306
-0.5
21
21.5
369.923
7953.3445
0
21
21
369.923
7768.383
0.5
21
20.5
369.923
7583.4215
1
21
20
369.923
7398.46
1.5
21
19.5
369.923
7213.4985
2
21
19
369.923
7028.537
2.5
21
18.5
369.923
6843.5755
3
21
18
369.923
6658.614
3.5
21
17.5
369.923
6473.6525
4
21
17
369.923
6288.691
4.5
21
16.5
369.923
6103.7295
5
21
16
369.923
5918.768
5.5
21
15.5
369.923
5733.8065
6
21
15
369.923
5548.845
6.5
21
14.5
369.923
5363.8835
7
21
14
369.923
5178.922
7.5
21
13.5
369.923
4993.9605
8
21
13
369.923
4808.999
8.5
21
12.5
369.923
4624.0375
9
21
12
369.923
4439.076
9.5
21
11.5
369.923
4254.1145
10
21
11
369.923
4069.153
10.5
21
10.5
369.923
3884.1915
11
21
10
369.923
3699.23
11.5
21
9.5
369.923
3514.2685
12
21
9
369.923
3329.307
12.5
21
8.5
369.923
3144.3455
13
21
8
369.923
2959.384
13.5
21
7.5
369.923
2774.4225
14
21
7
369.923
2589.461
14.5
21
6.5
369.923
2404.4995
15
21
6
369.923
2219.538
15.5
21
5.5
369.923
2034.5765
16
21
5
369.923
1849.615
16.5
21
4.5
369.923
1664.6535
17
21
4
369.923
1479.692
17.5
21
3.5
369.923
1294.7305
18
21
3
369.923
1109.769
18.5
21
2.5
369.923
924.8075
19
21
2
369.923
739.846
19.5
21
1.5
369.923
554.8845
20
21
1
369.923
369.923
20.5
21
0.5
369.923
184.9615
21
21
0
369.923
0
Month July
Qsolar
Qinternal
Qtotal Heat gain
440.8292555
965.048706
1356.140525
87
Monthly Balance Points Cooling Period (July) Qtotal
June
-1.000
8138.306
1356.140525
-0.500
7953.3445
1356.140525
0.000
7768.383
1356.140525
0.500
7583.4215
1356.140525
1.000
7398.46
1356.140525
1.500
7213.4985
1356.140525
2.000
7028.537
1356.140525
2.500
6843.5755
1356.140525
3.000
6658.614
1356.140525
3.500
6473.6525
1356.140525
4.000
6288.691
1356.140525
4.500
6103.7295
1356.140525
5.000
5918.768
1356.140525
5.500
5733.8065
1356.140525
6.000
5548.845
1356.140525
6.500
5363.8835
1356.140525
7.000
5178.922
1356.140525
7.500
4993.9605
1356.140525
8.000
4808.999
1356.140525
8.500
4624.0375
1356.140525
9.000
4439.076
1356.140525
9.500
4254.1145
1356.140525
10.000
4069.153
1356.140525
10.500
3884.1915
1356.140525
11.000
3699.23
1356.140525
11.500
3514.2685
1356.140525
12.000
3329.307
1356.140525
12.500
3144.3455
1356.140525
13.000
2959.384
1356.140525
13.500
2774.4225
1356.140525
14.000
2589.461
1356.140525
14.500
2404.4995
1356.140525
15.000
2219.538
1356.140525
15.500
2034.5765
1356.140525
16.000
1849.615
1356.140525
16.500
1664.6535
1356.140525
17.000
1479.692
1356.140525
17.500
1294.7305
1356.140525
18.000
1109.769
1356.140525
18.500
924.8075
1356.140525
19.000
739.846
1356.140525
19.500
554.8845
1356.140525
20.000
369.923
1356.140525
20.500
184.9615
1356.140525
21.000
0
1356.140525
Balance Point c 17.41 Balance point read off graph below through excel
88
Â
Average annual balance point- 17.0016 Heating average balance point- 16.695 Cooling average balance point-17.92 This balance point is incredibly high compared to my expected balance point taking into account previous data from the investigation, this suggests despite ventilation flow rate being corrected in the our methodology by 50% this figure is still overstating considering my occupant habits.
Degree Days Month starting
14
14.5
15
15.5
16
16.5
17
17.5
18
18.5
19
19.5
20
01/01/2009
320
336
351
367
382
398
413
429
444
460
475
491
506
01/02/2009
250
264
278
292
306
320
334
348
362
376
390
404
418
01/03/2009
184
199
214
229
245
260
276
291
307
322
338
353
369
01/04/2009
92
104
116
129
142
156
170
184
198
213
228
242
257
01/05/2009
47
56
65
75
86
97
109
122
134
148
161
175
189
01/06/2009
17
22
27
34
40
47
55
64
72
82
92
102
113
01/07/2009
3
5
7
12
17
23
30
38
46
56
65
77
88
01/08/2009
4
6
8
10
13
17
22
28
36
44
52
62
72
01/09/2009
15
20
25
32
39
48
56
66
76
88
100
113
127
01/10/2009
62
74
86
99
112
126
140
155
170
186
201
216
232
01/11/2009
124
139
153
168
183
198
213
228
243
258
273
288
303
01/12/2009
298
313
329
344
360
375
391
406
422
437
453
468
484
01/01/2010
366
382
398
413
428
444
459
475
490
506
521
537
552
01/02/2010
280
294
308
322
336
350
364
378
392
406
420
434
448
01/03/2010
216
231
247
262
277
293
308
324
339
355
370
386
401
01/04/2010
123
135
147
160
173
187
200
215
229
243
258
273
288
01/05/2010
93
104
115
126
138
151
164
177
190
204
218
232
246
01/06/2010
16
20
25
31
37
44
51
59
67
76
85
95
105
01/07/2010
1
2
3
6
8
11
15
20
25
32
38
46
54
01/08/2010
10
14
18
23
29
36
43
51
60
71
81
93
105
01/09/2010
32
39
46
55
64
74
85
96
108
121
133
147
160
01/10/2010
95
107
119
133
146
160
175
190
205
220
235
251
266
01/11/2010
231
245
259
273
288
302
317
332
347
362
377
392
407
01/12/2010
390
405
421
436
452
467
483
498
514
529
545
560
576
01/01/2011
277
292
308
323
339
354
370
385
401
416
432
447
463
01/02/2011
187
201
215
229
243
257
271
285
299
313
327
341
355
01/03/2011
202
216
231
246
261
276
292
307
322
338
353
369
384
01/04/2011
64
74
83
94
104
115
127
139
151
163
176
189
202
01/05/2011
50
58
67
77
88
99
111
124
137
151
164
179
194
01/06/2011
28
35
42
50
58
68
77
88
99
110
123
135
148
01/07/2011
8
12
16
22
29
36
44
54
63
74
85
97
109
01/08/2011
8
12
16
22
28
36
44
54
64
75
86
98
110
01/09/2011
16
21
26
33
39
48
56
66
77
88
100
113
125
01/10/2011
57
66
74
85
95
108
120
134
147
162
176
191
206
01/11/2011
116
130
144
159
174
188
203
218
233
248
263
278
293
01/12/2011
216
231
247
262
278
293
309
324
340
355
371
386
402
2009
2010
2011
AVG
Balance Point
HLC
kWh
Jan
413
459
370
414
17.22
272.3493
2706.062645
Feb
334
364
271
323
16.89
272.3493
2111.251774
Mar
260
293
276
276.3333333
16.51
272.3493
1806.220558
Apr
142
173
104
139.6666667
16.21
272.3493
912.9148536
138
88
75.33333333
16.12
272.3493
492.4075344
May Jun
-
-
-
-
-
-
-
Jul
-
-
-
-
-
-
-
Â
89 Aug
-
-
-
-
-
-
-
Sep
48
74
48
56.66666667
16.34
272.3493
370.395048
Oct
126
160
108
131.3333333
16.48
272.3493
858.4449936
Nov
213
317
203
244.3333333
17.16
272.3493
1597.056295
Dec
406
498
324
409.3333333
17.33
272.3493
2675.559523
Total kWh- 13530.31322 Total Energy
Emission factor
Boiler efficiency
Carbon emissions
13530.31322
0.19
0.93
2764.25754
Predicted Cost
426.2048666
Property Area
120.89
kWh/m2
111.9225182
Comparison with housing standards
Actual
New build
PassivHaus
0
20
40
60
80
100
120
Conclusion
The above graph shows the house’s total energy consumption per m2 of the dwelling. This shows that the building is highly outperformed by stated standards. This suggests that the building will need to be heated through the cooling period the majority of time. This figure could be high due to the aspect of the building. The predominately north facing building receives very little in the way of solar gains. Passiv Haus recommends optimising south facing aspects to increase solar gains within the building utilising the concept of natural heating to a designer’s advantage. In the case of my home the large fence the property is backed onto prevented this design implication. However due to the build date of 2010 this total energy consumption must have been lower to fall into new build guidelines. The fabric heat losses within the dwelling are very low falling well within the new built guidelines. This suggests that the main imperfect variable in the calculation method is HLC ventilation. As mentioned earlier this value was most likely overstated methodologically with a reduction in the ventilation flow rate of 50%. Taking into account occupant habits this value is more likely to be around 20-25% (as a maximum) during the cooling period (assuming all window opening are fully open) Through a change in the kWh/m2, to calculate a given reduction in the HLCventilation by around 50% (bringing ventilation flow rate to 25%), it can be estimated that the energy consumption would be around 55.961125 kWh/m2. This value falls within the new build guidelines. Existing energy bill information further backs up this estimation, as the total kWh would be reduced to an estimate of around 6765.15661 kWh and the energy bills for the house states a calculated consumption of 73804 kWh. The scope for renovation and improvement within this build depends on the calculations taken. Original energy calculations could easily be improved through an increase in the size of openings to increase solar gains. However a more pragmatic approach may lead towards the installation of a mechanical heat recovery ventilation system. This would build on the existing tight building fabric tackling ventilation through controlling hot and cold air exchanges within the building, in theory dramatically reducing HLC ventilation and the subsequent result of an extremely low energy consumption value. When the concept is placed in a realistic sense, the cost of the MVHR system may not be worth the reduction in energy bill as currently a low bill exists of around £738.05 P.A possibly making it financially unviable.
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120
Individual Analysis Conclusion
Through individual analysis of our dwellings, three distinct housing construction typologies emerged. One of which would be redesigned to improve its environmental performance; aiming to reach a PassivHaus standard and an optimum occupant comfort level. The studied typologies are: • Cavity Wall Detached Houses- located in Newport, Wales (Jonathon H) & Watford, England (Jonathan B) • Cavity Wall Semi-Detached House- located in Nottingham, England • Timber Frame Detached House- Located in Beaconsfield, England Fabric Comparison
Wall U-Value
Roof U-Value 1.2
0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0
1 0.8 0.6 0.4 0.2 0 Jonathan B
Lidan
Cameron
Jonathon H PassivHaus
Jonathan B
Lidan
Cameron
Jonathon H PassivHaus
The highest wall U- values are in the two detached cavity wall structures. Jonathon H’s composite wall structure has the original insulation installed in 1999. Jonathan B’s insulation was installed into a previously empty cavity in 1976. The age of Jonathan B’s insulation suggests a large scope to reduce the Wall U-Value towards PassivHaus standard by replacing this with a better performing material.
From the graph it is visible that Jonathan B’s roof structure has considerably higher U-Values in some of the roof elements than the other dwellings analysed. The original flat roof structure takes up 10% of the total roof area and currently has no insulation. This weak spot in the envelope could be easily improved, creating a better performing roof system. When analysing bridging at structural joints and through building fabric, numerous easily avoidable geometric bridges occur. Cameron’s dwelling comes relatively close to PassivHaus values. Timber frame constructions are common in PassivHaus builds, with cavity wall systems being less common. This wall design gives Cameron’s house potential to easily reach PassivHaus standard without too much renovation. Issues and Strategies | Detached Cavity Wall (Jonathan B) Moisture in the bathrooms often escapes into the rest of the house after shower use, displaying an inadequate extraction system that could be solved by a more efficient MV system. Likewise a more efficient extraction system in the kitchen would be beneficial as odours escape into the rest of the house lingering in the downstairs reception rooms. These two issues have knock on effects on occupant comfort and could be easily resolved. By using a heat exchanger it is likely that warmth will be equally spread around the house also. The current heating system struggles to supply to some of the furthest radiators, with those in the far west extension of the house much more inefficient than those in the main spaces. Locating the exchanger centrally, rather than the current boiler location (in the garage on the far east side), a more efficient supply will be sustained. |Detached Timber Frame (Cameron) Ventilation problems exist on the south façade rooms on the ground floor level. Air from the bathroom seeps into the bedroom leading to condensation builds up on windows and a high constantly varying humidity within the space. These windows open to an extremely sheltered area not sufficient to solve the problem. The location of these windows was fixed due to planning regulations; therefore the only plausible ventilation strategy that exists is Mechanical. The well-ventilated first floor spaces are nicer living areas than the ground floor as a result of this issue. |Detached Cavity Wall (Jonathon H) There is no obvious (if any) cross or stack ventilation options that occur within the building. To help incorporate greater ventilation throughout some of the rooms in the house, there are some basic renovation details that could be addressed. For example, if the study was switched with the dining room on the ground floor and the wall was knocked through to the kitchen,
cross ventilation would then occur in these rooms. Creating a kitchen-diner, would also be a much better use of the space and 121 allow more room in the study (which is what is needed!) |Semi-Detached Cavity Wall (Lidan) Neighbours’ houses and bushes both from the front and the rear surround the house, as a consequence, the ventilation is quite inefficient through these objects. Within the house, the air change rate is limited because no short cross or stack ventilation happens. Therefore, as the wind mostly blows from southwest, the bedrooms facing north are not good ventilated which occurs bad air quality. Gains
Solar Gains (W)
Internal Gains (W)
12000
2000 1800 1600 1400 1200 1000 800 600 400 200 0
10000 8000 6000 4000 2000 0 Jonathan B
Lidan
Cameron
Jonathon H
Jonathan B
Lidan
Cameron
Jonathon H
PassivHaus suggests optimising south facing aspects as a form of natural heating. Jonathan B’s front façade is orientated south. As we will not be re-orientating the building or changing any form, this presents the ideal starting point for a PassivHaus redesign. The proportion of the total roof area facing south is around 40%, giving this house the opportunity to attached photovoltaic cells and produce its own energy. Internal gains give somewhat of a skewed value for reaching PassivHaus carbon emission guidelines. There is a fine balance to achieve between providing new eco technology to reduce electricity usage and utilising waste heat from existing appliances to your design advantage. For example the replacement of high-energy bulbs with energy saving ones provides a simple cost effective solution for reducing carbon emissions, compared to the relative cost of replacing a tumble drier. Due to the similar amount of occupants within each dwelling, their impact on gains is negligible.
Chosen Re-design From this evaluation we have chosen to redesign Jonathan B’s detached house. As well as being one of the worse thermal performing houses within the report, there are a number of opportunities linked with the design and location as outlined above. Our methodological approach remains the same, relating to PassivHaus as a benchmark for unsurpassed environmental performance. A full redesign will be implemented pushing towards PassivHaus standards without altering the aesthetic character or layout of the dwelling. Being located in a small close of 15 Georgian style dwellings, this approach would be necessary to ensure approval of the project on a public and legal level.
Layout & User Comfort
122
Based on the analysis from the previous individual project we found there was a design opportunity to increase the occupant comfort in the study room by rearranging it with the TV room. The south facing aspect of the study is inappropriate for its use, with issues arising from glare throughout the day. By swapping this with the second lounge, a more suited environment is achievable. Although the glare will also affect the use of the TV, it is used less often and the removal of glare within the study workspaces is of greater importance. The new study location would receive little direct light, and rarely overheat.
PassivHaus When considering PassivHaus as a solution, it is essential that we keep to the guidelines regarding construction and post build usage. It requires us to construct an airtight envelope with extremely low U-values and an integrated mechanical ventilation system. PassivHaus design specifies that u-values for the wall construction should be no more than 0.15W/m²K. In order to reach this value, we will have to make a significant alteration to the original thickness of the insulation within the wall. All the existing windows of the house will also need to be replaced in order to comply with the maximum u-value of 0.80W/m2 K. Due to the airtight envelope, a means of mechanical ventilation with a heat recovery system will need to be incorporated into the design to allow a steady rate of air flow, taking stale air out of the building and bringing fresh air in. We will therefore also have to consider the desired air change rate to prevent excessive heat loss. Construction detailing at junctions and corners must be thought about carefully to try and minimise any geometric bridging, as this will now have a greater effect on the outcome of our total fabric heat loss. PassivHaus guidelines also specify that the overall energy use within the building, for both heating and cooling can be no greater than15kWh/m²a and that the total primary energy can be no more than 120 kWh/m² per year.
House Plan
123
Cavity Wall Design
In order to obtain lower cavity wall U-values, more resistive and thicker cavity wall insulation must be used. Cavity walls are not common in PassivHaus buildings, with other methods being recommended to create the best thermal results. Research into insulation manufacturers showed a cavity thickness of 300mm was best suited to obtain PassivHaus results with the cavity construction.
Cavity wall - Upper value
(Values from CIBSE Guide A & Conductivity values for earth wool from http://www.knaufinsulation.co.uk. Calculations using equation 1) Layer Material Proportion of surface area (%) Thickness (mm) Conductivity λ (W/mK) Resistance (m 2 K/W) 1 External surface 0.04 2A Brickwork outer leaf 0.9 100 0.77 0.12987013 2B Mortar 0.1 100 0.88 0.113636364 3A Earthwool DriTherm Cavity Slab 32 0.999 300 0.032 9.375 3B Stainless steel tie 0.001 5 17 0.000294118 4A AAC Block work 0.93 100 0.11 0.909090909 4B Mortar 0.07 100 0.88 0.113636364 5 Plaster 1 10 0.22 0.045454545 6 Internal Surface 0.12 (Calculations using equation 2) Path/Layer fractional area 1 2 3 4 5 6 7 8
2 0.9 0.9 0.9 0.9 0.1 0.1 0.1 0.1
3 0.999 0.001 0.999 0.001 0.999 0.001 0.999 0.001
4 0.93 0.93 0.07 0.07 0.93 0.93 0.07 0.07
5 1 1 1 1 1 1 1 1
F total 0.836163 0.000837 0.062937 0.000063 0.092907 0.000093 0.006993 0.000007
Resistance (m 2 K/W) 10.61941558 1.244709702 9.823961039 0.449255157 10.60318182 1.228475936 9.807727273 0.43302139
F/R 0.078739079 0.000672446 0.006406479 0.000140232 0.008762181 7.57036E-05 0.000713009 1.61655E-05
Total R Upper (1/Total)
0.095525295 10.4684314
Cavity wall - Lower value (Calculations using equation 3) Layer Fractional area, F 2A 0.9 2B 0.1 3A 0.999 3B 0.001 4A 0.93 4B 0.07
Thermal resistance per path (m 2 K/W) 0.12987013 0.113636364 9.375 0.000294118 0.909090909 0.113636364
F/R 6.93 0.88 0.10656 3.4 1.023 0.616
Path total 7.81
1/Total 0.128040973
3.50656
0.285179777
1.639
0.610128127
Layer 1 2 3 4 6 7
Material External surface Brickwork outer leaf & mortar Insulation & ties AAC Block work & mortar Plaster Internal Surface R lower
Thermal Resistance (m 2 K/W) 0.04 0.128040973 0.285179777 0.610128127 0.045454545 0.12 1.228803423
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Cavity wall - Total (Calculations using equation 4) R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W) Wall U-Value W/m2 K
10.4684314 1.228803423 5.848617411 0.17098058
The value of 0.17 is a massive improvement on the previous cavity wall value of 0.44, but falls just short of the 0.15 values for PassivHaus standard. This shows potentially the reasons for not utilising cavity construction in new build methods potentially due to the conductivity of mortar and brickwork.
Cavity Wall Design – Continued It was found that a 39.5mm layer of internal plasterboard insulation could lower the u value to a value to within PassivHaus standards.
Cavity wall - Upper value (Values from CIBSE Guide A & Conductivity values for earth wool from http://www.knaufinsulation.co.uk. Calculations using equation 1) Layer Material Proportion of surface area (%) Thickness (mm) Conductivity λ (W/mK) Resistance (m 2 K/W) 1 External surface 0.04 2A Brickwork outer leaf 0.9 100 0.77 0.12987013 2B Mortar 0.1 100 0.88 0.113636364 3A Earthwool DriTherm Cavity Slab 32 0.999 300 0.032 9.375 3B Stainless steel tie 0.001 5 17 0.000294118 4A AAC Block work 0.93 100 0.11 0.909090909 4B Mortar 0.07 100 0.88 0.113636364 5 Gyproc wallboard 1 9.5 0.19 0.05 6 Super phenolic foam 30 0.02 1.5 7 Internal Surface 0.12
(Calculations using equation 2) Path/Layer fractional area 1 2 3 4 5 6 7 8
2 0.9 0.9 0.9 0.9 0.1 0.1 0.1 0.1
3 0.999 0.001 0.999 0.001 0.999 0.001 0.999 0.001
4 0.93 0.93 0.07 0.07 0.93 0.93 0.07 0.07
5 1 1 1 1 1 1 1 1
6 1 1 1 1 1 1 1 1
F total 0.836163 0.000837 0.062937 0.000063 0.092907 0.000093 0.006993 0.000007
Resistance (m 2 K/W) 12.12396104 2.749255157 11.32850649 1.953800611 12.10772727 2.73302139 11.31227273 1.937566845
F/R 0.068967807 0.000304446 0.005555631 3.22448E-05 0.007673364 3.40283E-05 0.000618178 3.61278E-06
Total R upper - 1/Total
0.083189312 12.02077502
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Cavity wall - Lower value (Calculations using equation 3) Layer Fractional area, F 2A 0.9 2B 0.1 3A 0.999 3B 0.001 4A 0.93 4B 0.07 Layer 1 2 3 4 5 6 7
Thermal resistance per path (m 2 K/W) 0.12987013 0.113636364 9.375 0.000294118 0.909090909 0.113636364
Material External surface Brickwork outer leaf & mortar Insulation & ties AAC Block work & mortar Gyproc wallboard Super phenolic foam Internal Surface R lower
F/R 6.93 0.88 0.10656 3.4 1.023 0.616
Path total 7.81
1/Total 0.128040973
3.50656
0.285179777
1.639
0.610128127
Thermal Resistance (m 2 K/W) 0.04 0.128040973 0.285179777 0.610128127 0.05 1.5 0.12 2.733348877
Cavity wall - Total
(Calculations using equation 4) R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W) Wall U-Value W/m2 K
12.02077502 2.733348877 7.377061949 0.135555321
When applying the extra internal insulation the total u-value falls within PassivHaus requirements. However, we have made a decision against the installation of this plasterboard due to the loss of volumetric space and the cost implications of applying the additional layer.
Roof/Ceiling Design Main roof
Main roof - Upper value (Values from CIBSE Guide. Calculations using equation 1) Layer Material Proportion of surface area 1a Timber joists 0.1 1b Insulation 0.9 2 Insulation above joists 1 3 Plasterboard 1 4 Plaster 1 5 Internal surface (Calculations using equation 2) Path F Total 1 1 0.9 1 0.9 2 1 1 0.1 0.1 3
Thickness (mm) 150 150 200 10 10 -
Resistance total (m 2 K/W) 8.1625 5.907255245
F/R 0.110260337 0.016928336
Total R upper (1/Tota)l
0.127188673 7.862335374
Conductivity λ (W/mK) 0.13 0.044 0.044 0.16 0.22 -
Resistance (m 2 K/W) 1.153846154 3.409090909 4.545454545 0.0625 0.045454545 0.1
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Main roof - Lower value (Calculations using equation 3) Layer Fractional area, F 1a 0.1 1b 0.9 Layer 1 2 3 4 5
Thermal resistance per path (m 2 K/W) 1.153846154 3.409090909
Material Timber/Insulation Insulation above joists Plasterboard Plaster Internal surface R Lower
F/R 0.0867 0.264
Path total 0.3507
1/Total 2.851711027
Thermal Resistance 2.851711027 4.545454545 0.0625 0.045454545 0.1 7.605120118
Main roof - Total R upper (m 2 K/W) R lower (m 2 K/W) R Total (m2 K/W)
7.862335374 7.605120118 7.733727746
(CIBSE Guide A - table 3.5 used for surface resistance. Table 3.9 for pitched roof resistance. Calculations using equation4) Layer Material Thermal Resistance 1 External surface 0.4 2 Pitched roof 0.2 3 Bridged ceiling 7.733727746 R TOTAL (m2 K/W) U-Value (W/m2 K)
8.333727746 0.119994321
Flat roof
Flat roof - Upper value (Values from CIBSE Guide A. Calculations using equation 1) Layer Material Proportion of surface area 1 External surface 2 Bitumen 1 3 Bitumen felt 1 4 Insulation 1 5 Plywood deck 1 5A Air cavity (unvented) 0.8 5B Timber joists 0.2 6 Plasterboard 1 7 Internal Surface (Calculations using equation 2) Path 2 3 4 5 6 1 1 1 1 1 0.8 2 1 1 1 1 0.2
Thickness (mm) 5 15 150 19 150 12.5 -
Conductivity λ (W/mK) 0.5 0.19 0.025 0.12 0.13 0.16 -
F Total
Resistance total (m 2 K/W)
F/R
0.8 0.2
7.005405702 7.979251856
0.114197526 0.025065007
Total R upper (1/Total)
0.139262533 7.18068228
Resistance (m 2 K/W) 0.4 0.01 0.078947368 6 0.158333333 0.18 1.153846154 0.078125 0.1
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Flat roof - Lower value (Calculations using equation 3) Layer Fractional area, F
Thermal resistance per path (m 2 K/W)
F/R
Path total
1/Total
0.18 1.153846154
4.444444444 0.173333333
4.617777778
0.216554379
4a 4b
0.8 0.2
Layer
Material
Thermal Resistance (m 2 K/W)
1 2 3 4 5 6 7 9
External surface Bitumen Felt Insulation Plywood deck Unvented gap & timber joists Plasterboard Internal Surface R lower
0.4 0.01 0.078947368 6 0.158333333 0.216554379 0.078125 0.1 7.041960081
Roof - Total R upper (m 2 K/W) R lower (m 2 K/W) R TOTAL (m 2 K/W) F/roof U value
7.18068228 7.041960081 7.111321181 0.140620846
Roof values have significantly improved, especially with the inclusion of insulation in the flat roof construction; previously a weak spot in the thermal envelope. Quilt insulation thickness has been increased in the loft to 350mm from the original 100mm.
Floor Design (Calculations using equation 4 & CIBSE table values) Perimeter (m) Area (m2) P/A (m/m2) Thermal resistance 48.915 99.8855 0.489710719 2.5 U Value 0.24
Due to the large perimeter to area ratio of the ground floor, the u value is still relatively high for PassivHaus. Because the internal layout of the house is to remain the same, we were unable to calculate a smaller value.
Openings Design U Value Triple glazed openings
0.776
To lower the glazing U – Value to a desired value of 0.8 we have replaced the existing with low – E coated triple glazed units with 16mm argon filled cavities & thermix insulated warm edge spacers. This glazing u value falls below PassivHaus requirements, providing good thermal performance in comparison to the original double-glazing.
128
Geometric Bridging
Geometric bridging in PassivHaus plays a big part in thermal losses, with values accounting for a higher proportion of envelope losses as HLC values for fabric decrease. Good construction detailing can help reduce geometric bridging as shown in the diagrams below. However, SAP2009 only supplies generic values for thermal transmittance so the table remains the same. FRONT 1 Ground floor Flat roof Corners WEST 1 Ground floor Flat roof Inverted corner FRONT 2 Ground floor Intermediate floor Eaves Corners WEST 2 Ground floor Intermediate Gable Corners FRONT 3 Ground floor Intermediate Eaves Corners WEST 3 Ground floor Intermediate Gable Corners FRONT 4 Ground floor Intermediate Eaves Corners WEST 3 Ground floor Intermediate Gable Corners REAR 1 Ground floor Intermediate Eaves Corners REAR 2 EXTENSION Ground floor Flat roof Corners EAST 1 EXTENTION Ground floor Flat roof Corners FRONT 5 EXTENTION Ground floor Flat roof Corners EAST 2 Ground floor Intermediate Gable EAST 3 Intermediate Gable TOTAL (W/K)
Linear thermal transmittance ψ (W/mK)
Length of bridge L (mm)
(Lx ψ) W/K
0.16 0.04 0.09
2700 2700 4800
0.432 0.108 0.432
0.16 0.04 -0.09
1775 1775 2400
0.284 0.071 -0.216
0.16 0.07 0.06 0.09
5860 8560 8560 7900
0.9376 0.5992 0.5136 0.711
0.16 0.07 0.24 -0.09
1600 1600 1600 5150
0.256 0.112 0.384 -0.4635
0.16 0.07 0.06 0.09
2975 2975 2975 5150
0.476 0.20825 0.1785 0.4635
0.16 0.07 0.24 -0.09
1100 1100 1100 5150
0.176 0.077 0.264 -0.4635
0.16 0.07 0.06 0.09
500 500 500 5150
0.08 0.035 0.03 0.4635
0.16 0.07 0.24 -0.09
4950 4950 4950 5150
0.792 0.3465 1.188 -0.4635
0.16 0.07 0.06 0.09
12025 12025 12025 5150
1.924 0.84175 0.7215 0.4635
0.16 0.04 0.09
2875 2875 2650
0.46 0.115 0.2385
0.16 0.04 0.09
4000 4000 2650
0.64 0.16 0.2385
0.16 0.04 -0.09
2875 2875 2650
0.46 0.115 -0.2385
0.16 0.07 0.24
5425 3650 3650
0.868 0.2555 0.876
0.07 0.24
4000 4000
0.28 0.96 17.3909
129
Geometric bridging illustration – Wall to roof
A continuous route of insulation around the house envelope helps to minimise heat loss at geometric bridges. Bridging technologies such as thermoblocks have been inserted into block work to prevent thermal transmittance through the materials at junctions. These help to continue this consistent route of insulation.
150mm of insultion at rafter level
Two large layers of insulation at ceiling level stored within the joists.
Roof and wall insulation extended to connect a fluid path preventing the illustrated geometric bridge.
Continuous ribbon of adhesive behind plasterboard
Geometric bridging illustration – Wall to ground
.
130
Building Fabric Analysis (Calculations using equation 5. HLC is based on corrected surface areas of exterior walls following the cavity redesign) U-Value (W/m 2 K) AREA (m 2 ) HLC (UxA (W/K) Heat loss geometric bridging HLC TOTAL (W/K) Ground 0.24 99.8855 23.97252 23.97252 Roof 0.119994321 84.2175 10.10562171 10.10562171 Flat roof 0.140620846 14.8625 2.089977322 2.089977322 South facing walls 0.135555321 60.0135 8.135149253 5.66815 13.80329925 East facing walls 0.135555321 47.15125 6.391602826 3.2395 9.631102826 West facing walls 0.135555321 53.68875 7.277795737 2.344 9.621795737 North facing walls 0.135555321 55.8375 7.569070233 3.95075 11.51982023 Windows 0.776 36.28 28.15328 28.15328 Doors 0.776 4.2 3.2592 3.2592 Total
112.1566171
250
200
150
Area (m2) HLC (W/K)
100
50
0 Original Floor
Floor
Original Roof
Roof
Original Walls
Walls
Original Windows
Windows
Original Doors
Doors
(Calculations using equations 12, 14 and 15) HLC Total
112.1566171
Ti - To
9
Heat Loss (W)
1009.409554
Energy (J)
31832739685.36
Energy (kWh)
8842.42769
Emissions
0.19 2
Carbon emissions (kg co )
1680.061261
Air tightness PassivHaus requirements necessitate an airtight envelope with an air change rate of ≥ 0.6 air changes per hour at 50pa. Doors and windows will have draft proof seals and good construction techniques to minimise unsealed leakages through the envelope.
Ventilation
131
This airtight envelope will be ventilated by a mechanical ventilation heat recovery system (MVHR). The system will be installed with ducts across the house with minimum turns and manoeuvres to maximise air flow potential. Supply ducts will be fitted 100mm from ground level in all living and reception spaces within the house providing these areas with fresh air. Extract ducts will be fitted 100mm from the ceiling to kitchen, bathroom and utility areas to remove waste air, preventing the build up of moisture and toxins. These must be located below 400mm from the ceiling height as described in building regulations part F table 5.2C.
The chosen air change rate for the dwelling is 0.4 air changes per hour. This is recommended by PassivHaus for domestic settings, creating a healthy balance between air quality and minimal heat loss.
132
During the winter months the heat recovery system is used to recover heat from the waste exhaust air, heating up the inlet air supply without contaminating it. The Paul MVHR Novus 300 is a manufacture example of a heat recovery system to be installed in the house. This particular model has a heat recovery efficiency of 93% and has been factored into the calculations below. During the summer months the heat recovery element of the system can be bypassed, with exhaust air escaping without heating up the inlet air. This helps regulate a healthy and comfortable temperature without chance of overheating. Due to the large amount of insulation, overheating may occur. If so, window openings can be used to trigger cross and single sided ventilation within the house volumes. Based on the PassivHaus benchmark value for N, we calculated the volume flow rate, Q. This was then used to calculate effective areas for the vent sizes showing the proportion of ventilation supply/extraction in relation to room volume. (Calculations using equations 9 and 17) N Living room Supply 0.4 TV room Supply 0.4 Study Supply 0.4 Kitchen Extract 0.4 Bedroom 1 Supply 0.4 Bedroom 2 Supply 0.4 Bedroom 3 Supply 0.4 Bedroom 4 Supply 0.4 Spare bedroom Supply 0.4 Bathroom1 Extract 0.4 Bathroom 2 Extract 0.4 Hallway upstairs Supply 0.4 Hallway downstairs Supply 0.4 Utility room Extract 0.4
3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600 3600
V 58.752 45.144 25.596 57.36 33.966 33.078 30.894 17.496 28.608 12.7656 15.768 21.888 21.888 16.2
Q 0.0065 0.0050 0.0028 0.0064 0.0038 0.0037 0.0034 0.0019 0.0032 0.0014 0.0018 0.0024 0.0024 0.0018
Cd 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61 0.61
(TiTo )*2 1 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66 15.66
(TiTo)/2 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915 3.915
H 8.05 8.05 8.05 5.85 5.4 5.4 5.4 5.4 5.4 3.2 3.2 5.4 8.05 5.85
G 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81 9.81
273 273 273 273 273 273 273 273 273 273 273 273 273 273 273
1 0.2852 4.4659 4.4659 3.2454 2.9958 2.9958 2.9958 2.9958 2.9958 1.7753 1.7753 2.9958 4.4659 3.2454
2 0.3258 1.2891 1.2891 1.0989 1.0558 1.0558 1.0558 1.0558 1.0558 0.8128 0.8128 1.0558 1.2891 1.0989
Aw 0.0200 0.0039 0.0022 0.0058 0.0036 0.0035 0.0033 0.0018 0.0030 0.0017 0.0022 0.0023 0.0019 0.0016
Winter ventilation HLC The particularly low HLC values are due to the high efficiency rate (93%) of our chosen heat recovery system, with waste heat being recycled and used by inlet air. (Calculations using equation 10) N V Living room 0.4 58.752 TV room 0.4 45.144 Study 0.4 25.596 Kitchen 0.4 57.36 Bedroom 1 0.4 33.966 Bedroom 2 0.4 33.078 Bedroom 3 0.4 30.894 Bedroom 4 0.4 17.496 Spare bedroom 0.4 28.608 Bathroom1 0.4 12.7656 Bathroom 2 0.4 15.768 Hallway upstairs 0.4 21.888 Hallway downstairs 0.4 21.888 Utility room 0.4 16.2
HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16
Efficiency % 93 93 93 93 93 93 93 93 93 93 93 93 93 93
Real HLC 0.548352 0.421344 0.238896 0.53536 0.317016 0.308728 0.288344 0.163296 0.267008 0.1191456 0.147168 0.204288 0.204288 0.1512
Total winter HLC
3.9144336
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Summer ventilation HLC As mentioned previously, during the summer months (June, July August), the heat recovery element can be bypassed and heat is allowed to escape from extract ducts. This explains the higher HLC values below. (Calculations using equation 10) N V Living room 0.4 58.752 TV room 0.4 45.144 Study 0.4 25.596 Kitchen 0.4 57.36 Bedroom 1 0.4 33.966 Bedroom 2 0.4 33.078 Bedroom 3 0.4 30.894 Bedroom 4 0.4 17.496 Spare bedroom 0.4 28.608 Bathroom1 0.4 12.7656 Bathroom 2 0.4 15.768 Hallway upstairs 0.4 21.888 Hallway downstairs 0.4 21.888 Utility room 0.4 16.2
HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16
Efficiency % 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Real HLC 7.8336 6.0192 3.4128 7.648 4.5288 4.4104 4.1192 2.3328 3.8144 1.70208 2.1024 2.9184 2.9184 2.16
Total summer HLC
55.92048
Ventilation analysis
(Calculations using equation 12, 14 & 15) Summer HLC Total 55.92048 Ti - To 1.3 Heat loss (W) 72.696624 Energy (J) 577850924.9 Energy (kWh) 160.5141458 Emissions factor 0.19 Carbon emissions (KG CO 2 ) 30.4976877
Winter 3.9144336 10 39.144336 923305282.1 256.4736895 0.19 48.730001
Total 59.8349136 11.3 111.84096 1501156207 416.9878353 0.19 79.2276887
Original ventilation values for winter (Calculations using equation 12, 14 & 15) Winter HLC Total 228.78936 Ti - To 9 Heat loss (W) 2059.10424 Energy (J) 64935911313 Energy (kWh) 18037.75314 Emissions factor 0.19 Carbon emissions (KG CO 2 ) 3427.173097
134
Solar Gains
Horizontal/vertical solar flux conversion Representative Latitude (o N) 51.5
Solar radiation on the horizontal (W/m2) Jun Jul 214 204
Aug 177
(Calculations using equation 16 & Excel spreadsheet ‘converting horizontal to vertical solar flux) Façade orientation - 180 Façade orientation - 90 Façade orientation - 0 Results SVertical (m), W/m2 Results SVertical (m), W/m2 Results SVertical (m), W/m2 January 47.3233189 January 19.87256466 January 10.72641674 February 77.1832044 February 38.51867736 February 20.35879704 March 94.2460544 March 61.56524736 March 33.30872704 April 105.11436 April 91.409784 April 54.639576 May 108.549926 May 111.2196844 May 75.2159916 June 114.5726896 June 122.9558742 June 91.97853536 July 110.5232934 July 117.784192 July 85.34413644 August 107.4132642 August 104.9219255 August 67.65654372 September 99.990985 September 73.603769 September 41.085141 October 85.2918322 October 46.90850868 October 24.81434852 November 56.0693298 November 24.70675812 November 13.21801668 December 40.8904104 December 16.39290576 December 8.94448464
Opening characteristics (Calculations using values from CIBSE Guide A, Table 6b & 6d) Façade Solar transmittance Living room front S 0.57 Living room rear N 0.57 TV room front S 0.57 TV room rear N 0.57 Study S 0.57 Hallway downstairs S 0.57 Kitchen N 0.57 Kitchen 2 E 0.57 Bedroom 1 S 0.57 Bedroom 2 N 0.57 Bedroom 3 N 0.57 Bedroom 4 S 0.57 Spare bedroom N 0.57 Hallway upstairs S 0.57 Bathroom 1 E 0.57 Bathroom 2 S 0.57
Solar access 0.54 0.77 0.3 0.77 1 1 0.77 0.77 0.54 1 0.77 1 0.54 1 0.77 0.54
Opening area 2.9 5 2.16 2.16 2.9 3.1 6.4 0.6 2.16 2.88 2.88 1.44 2.16 1.44 0.9 1.44
Frame factor 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.7
Room solar gain values
(Calculations using spreadsheet ‘Calculating solar gains’. Utility room excluded due to absence of window) Liv S Liv N TV S TV N Study Hall D January 26.6123 14.8296 11.01198487 6.4064 49.2820 52.6808 February 43.4040 28.1467 17.96028468 12.1594 80.3778 85.9211 March 52.9993 46.0505 21.93075527 19.8938 98.1469 104.9157 April 59.1111 75.5411 24.45977521 32.6338 109.4650 117.0144 May 61.0431 103.9887 25.25922042 44.9231 113.0428 120.8389 June 64.4300 127.1635 26.66069824 54.9347 119.3149 127.5435 July 62.1528 117.9913 25.7184167 50.9722 115.0979 123.0356 August 60.4039 93.5375 24.99472286 40.4082 111.8591 119.5735 September 56.2300 56.8016 23.26758224 24.5383 104.1296 111.3110 October 47.9639 34.3067 19.84713642 14.8205 88.8221 94.9477 November 31.5306 18.2744 13.04715362 7.8945 58.3900 62.4169 December 22.9947 12.3661 9.515067651 5.3421 42.5829 45.5196
January February March April May
Bed 1 19.8216 32.3285 39.4754 44.0276 45.4666
Bed 2 11.0933 21.0552 34.4482 56.5087 77.7890
Bed 3 8.5419 16.2125 26.5251 43.5117 59.8975
Bed 4 24.4711 39.9117 48.7350 54.3551 56.1316
Bed 5 4.4928 8.5274 13.9515 22.8860 31.5045
Bath 1 4.9454 9.5856 15.3209 22.7479 27.6777
Hall U 24.4711 39.9117 48.7350 54.3551 56.1316 59.2460 57.1520 55.5438 51.7057 44.1047 28.9937 21.1446
Kitchen 18.9819 36.0278 58.9446 96.6926 133.1056 162.7693 151.0288 119.7281 72.7061 43.9126 23.3912 15.8286
Bath 2 13.2144 21.5523 26.3169 29.3517 30.3111
TOTAL 294.1536 499.4727 666.6034 857.8268 1005.5629
June July August September October November December
47.9893 46.2932 44.9905 41.8816 35.7248 23.4849 17.1271
95.1249 88.2636 69.9709 42.4906 25.6632 13.6702 9.2505
73.2462 67.9630 53.8776 32.7177 19.7607 10.5260 7.1229
59.2460 57.1520 55.5438 51.7057 44.1047 28.9937 21.1446
38.5256 35.7468 28.3382 17.2087 10.3936 5.5364 3.7464
30.5983 29.3113 26.1105 18.3168 11.6735 6.1484 4.0795
31.9928 30.8621 29.9937 27.9211 23.8166 15.6566 11.4181
1139.1846 1078.2819 952.2812 745.1434 567.6448 352.0537 251.9023
Total (W) Energy (J) Energy (kWh)
8410.1113 265,221,000,000 73672.57473
135
Monthly solar gains – Original & new values 1600.0000 1400.0000 1200.0000 1000.0000 800.0000 Solar gain
600.0000
Original Solar gain
400.0000 200.0000 0.0000
As can be seen by the graph above, solar gains have decreased from the original study. This is due to the installation of triple glazed low e coated glass. This makes an impact on the solar transmittance value, decreasing from 0.76 for PVC-U double-glazing to 0.57 for the new glazing construction. This lower value means less solar energy entering the internal volumes through the glazed openings in the envelope.
Internal Gains Lighting gains (Calculations using equation 14) Light type Living room front Incandescent 40W Living room rear Incandescent 40W TV room Incandescent 40W Study Incandescent 40W Hallway downstairs Incandescent 40W Kitchen main GU10 Halogen Kitchen side GU10 Halogen Breakfast room GU10 Halogen Bedroom 1 Incandescent 40W Bedroom 2 GU10 Halogen Bedroom 3 Incandescent 40W Bedroom 4 GU10 Halogen Spare bedroom GU10 Halogen Hallway upstairs Incandescent 40W Bathroom 1 GU10 Halogen Bathroom 2 GU10 Halogen Utility Room GU10 Halogen
No. Fittings 5 5 8 3 3 6 4 4 4 4 4 1 6 3 4 4 4
Power (W) 8 8 8 8 8 11 11 11 8 11 8 11 11 8 11 11 11
Total power (W) 40 40 64 24 24 66 44 44 32 44 32 11 66 24 44 44 44
Time (S) 21600 300 600 1800 1800 10800 18000 1200 7200 18000 0 21600 300 10800 3600 3600 1800 Total energy (J) Q L ighting (W)
Energy (J) 864000 12000 38400 43200 43200 712800 792000 52800 230400 792000 0 237600 19800 259200 158400 158400 79200 4493400 52.00694444
Following research into energy efficient bulbs we have found GU10 50w equivalent bulbs running at 11w, and incandescent 40w equivalent running at 8w.
136
Appliance gains (Calculations using equation 14) Appliance Living room front LCD TV Laptop TV room CRT TV Study Desktop computer LCD TV Kitchen main Oven Microwave Dishwasher Fridge/freezer Breakfast room LCD TV Bedroom 2 LCD TV Desktop computer Stereo Bedroom 4 LCD TV Laptop Stereo Spare bedroom Projector Stereo Bathroom 1 Power shower Bathroom 2 Power shower Utility Room Washing Machine Tumble drier
Power (W) 120 30 150 130 120 1200 1000 1200 500 120 120 130 90 120 30 90 220 90 240 240 500 4000
Time (S) 18000 7200 900 1800 600 3600 600 3600 86400 3600 10800 14400 7200 3600 28800 3600 600 600 1800 1200 1800 0
Energy (J) 2160000 216000 135000 234000 72000 4320000 600000 4320000 43200000 432000 1296000 1872000 648000 432000 864000 324000 132000 54000 432000 288000 900000 0
Total energy (J) QAppliance (W)
62931000 728.3680556
Metabolic gains (Calculations using equation 14) Gain (W) Time (S) Male 115 18000 140 7200 Male 115 14400 140 7200 Male 115 14400 265 2700 Female 115 9000 140 1800 Total energy (J) Q metabolic (W)
Metabolic energy (J) 2070000 1008000 1656000 1008000 1656000 715500 1035000 252000 9400500 108.8020833
Internal gains analysis Q Lighting (W)
108.8020833
Q Appliance (W)
728.3680556
Q me tabolic (W)
52.00694444
Q Total (W)
889.1770833
137
Balance Point
Total heat gains per month Month January February March April May June July August September October November December
QSolar 294.1536 499.4727 666.6034 857.8268 1005.5629 1139.1846 1078.2819 952.2812 745.1434 567.6448 352.0537 251.9023
QInternal 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833 889.1770833
Qtotal heat gain 1183.3307 1388.6498 1555.7805 1747.0039 1894.7400 2028.3617 1967.4590 1841.4582 1634.3205 1456.8219 1241.2308 1141.0794
Qtotal Heat loss (September – May) (Calculations using equation 12) To Ti Delta T HLC -1 21 22 116.0710507 -0.5 21 21.5 116.0710507 0 21 21 116.0710507 0.5 21 20.5 116.0710507 1 21 20 116.0710507 1.5 21 19.5 116.0710507 2 21 19 116.0710507 2.5 21 18.5 116.0710507 3 21 18 116.0710507 3.5 21 17.5 116.0710507 4 21 17 116.0710507 4.5 21 16.5 116.0710507 5 21 16 116.0710507 5.5 21 15.5 116.0710507 6 21 15 116.0710507 6.5 21 14.5 116.0710507 7 21 14 116.0710507 7.5 21 13.5 116.0710507 8 21 13 116.0710507 8.5 21 12.5 116.0710507 9 21 12 116.0710507 9.5 21 11.5 116.0710507 10 21 11 116.0710507 10.5 21 10.5 116.0710507 11 21 10 116.0710507 11.5 21 9.5 116.0710507 12 21 9 116.0710507 12.5 21 8.5 116.0710507 13 21 8 116.0710507 13.5 21 7.5 116.0710507 14 21 7 116.0710507 14.5 21 6.5 116.0710507 15 21 6 116.0710507 15.5 21 5.5 116.0710507 16 21 5 116.0710507 16.5 21 4.5 116.0710507 17 21 4 116.0710507 17.5 21 3.5 116.0710507 18 21 3 116.0710507 18.5 21 2.5 116.0710507 19 21 2 116.0710507 19.5 21 1.5 116.0710507 20 21 1 116.0710507 20.5 21 0.5 116.0710507 21 21 0 116.0710507
Qtotal heat loss 2553.563115 2495.52759 2437.492065 2379.456539 2321.421014 2263.385489 2205.349963 2147.314438 2089.278913 2031.243387 1973.207862 1915.172337 1857.136811 1799.101286 1741.065761 1683.030235 1624.99471 1566.959184 1508.923659 1450.888134 1392.852608 1334.817083 1276.781558 1218.746032 1160.710507 1102.674982 1044.639456 986.603931 928.5684056 870.5328803 812.4973549 754.4618296 696.4263042 638.3907789 580.3552535 522.3197282 464.2842028 406.2486775 348.2131521 290.1776268 232.1421014 174.1065761 116.0710507 58.03552535 0
138
January
February
March
April
May
June
July
August
September
October
November
December
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21
Qtotal heat loss
To
Balance points - (September – May)
2553.56 2495.53 2437.49 2379.46 2321.42 2263.39 2205.35 2147.31 2089.28 2031.24 1973.21 1915.17 1857.14 1799.10 1741.07 1683.03 1624.99 1566.96 1508.92 1450.89 1392.85 1334.82 1276.78 1218.75 1160.71 1102.67 1044.64 986.60 928.57 870.53 812.50 754.46 696.43 638.39 580.36 522.32 464.28 406.25 348.21 290.18 232.14 174.11 116.07 58.04 0.00
1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33 1183.33
1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65 1388.65
1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78 1555.78
1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00 1747.00
1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74 1894.74
2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36 2028.36
1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46 1967.46
1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46 1841.46
1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32 1634.32
1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82 1456.82
1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23 1241.23
1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08 1141.08
10.5 22.6202 58.0355 0.3898 4.0925 11 35.4153 58.0355 0.6102 6.7126
9 53.8327 58.0355 0.9276 8.3482 9.5 4.2028 58.0355 0.0724 0.6880
7.5 46.8568 58.0355 0.8074 6.0554 8 11.1787 58.0355 0.1926 1.5409
5.5 5.9381 58.0355 0.1023 0.5628 6 52.0974 58.0355 0.8977 5.3861
4.5 37.6032 58.0355 0.6479 2.9157 5 20.4323 58.0355 0.3521 1.7603
3.5 55.1538 58.0355 0.9503 3.3262 4 2.8817 58.0355 0.0497 0.1986
4 52.2867 58.0355 0.9009 3.6038 4.5 5.7489 58.0355 0.0991 0.4458
5 42.3569 58.0355 0.7298 3.6492 5.5 15.6786 58.0355 0.2702 1.4859
6.5 9.3258 58.0355 0.1607 1.0445 7 48.7097 58.0355 0.8393 5.8752
8 5.9338 58.0355 0.1022 0.8179 8.5 52.1018 58.0355 0.8978 7.6309
10 22.4848 58.0355 0.3874 3.8743 10.5 35.5508 58.0355 0.6126 6.4320
11 38.4044 58.0355 0.6617 7.2791 11.5 19.6311 58.0355 0.3383 3.8900
10.8051
9.0362
7.5963
5.9488
4.6760
3.5248
4.0495
5.1351
6.9197
8.4489
10.3063
11.1691
Lower
Upper
Balance Point
139
Balance Points Graph – September – May
3000.00
2500.00
2000.00
Qtotal heat loss January February March April
1500.00
May September October November December
1000.00
500.00
0.00 -1
4
9
14
19
24
Qtotal Heat loss (June – August)
Balance points (June - August)
(Calculations using equation 12) To Ti Delta T HLC -1 21 22 168.0770971 -0.5 21 21.5 168.0770971 0 21 21 168.0770971 0.5 21 20.5 168.0770971 1 21 20 168.0770971 1.5 21 19.5 168.0770971 2 21 19 168.0770971 2.5 21 18.5 168.0770971 3 21 18 168.0770971 3.5 21 17.5 168.0770971 4 21 17 168.0770971 4.5 21 16.5 168.0770971 5 21 16 168.0770971 5.5 21 15.5 168.0770971 6 21 15 168.0770971 6.5 21 14.5 168.0770971 7 21 14 168.0770971 7.5 21 13.5 168.0770971 8 21 13 168.0770971 8.5 21 12.5 168.0770971 9 21 12 168.0770971 9.5 21 11.5 168.0770971 10 21 11 168.0770971 10.5 21 10.5 168.0770971 11 21 10 168.0770971 11.5 21 9.5 168.0770971 12 21 9 168.0770971 12.5 21 8.5 168.0770971 13 21 8 168.0770971 13.5 21 7.5 168.0770971 14 21 7 168.0770971 14.5 21 6.5 168.0770971 15 21 6 168.0770971 15.5 21 5.5 168.0770971 16 21 5 168.0770971 16.5 21 4.5 168.0770971 17 21 4 168.0770971 17.5 21 3.5 168.0770971 18 21 3 168.0770971 18.5 21 2.5 168.0770971 19 21 2 168.0770971 19.5 21 1.5 168.0770971 20 21 1 168.0770971 20.5 21 0.5 168.0770971 21 21 0 168.0770971
To -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21
Qtotal heat loss 3697.696136 3613.657588 3529.619039 3445.580491 3361.541942 3277.503393 3193.464845 3109.426296 3025.387748 2941.349199 2857.310651 2773.272102 2689.233554 2605.195005 2521.156457 2437.117908 2353.079359 2269.040811 2185.002262 2100.963714 2016.925165 1932.886617 1848.848068 1764.80952 1680.770971 1596.732422 1512.693874 1428.655325 1344.616777 1260.578228 1176.53968 1092.501131 1008.462583 924.4240341 840.3854855 756.346937 672.3083884 588.2698399 504.2312913 420.1927428 336.1541942 252.1156457 168.0770971 84.03854855 0
June 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617 2028.3617
July 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459 1967.459
August 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582 1841.4582
Lower
8.5 11.4365348 84.03854855 0.136086772 1.156737562
9 34.57238335 84.03854855 0.411387202 3.702484818
10 76.64868045 84.03854855 0.912065734 9.120657338
Upper
9 72.60201375 84.03854855 0.863913228 7.775219052
9.5 49.4661652 84.03854855 0.588612798 5.591821581
10.5 7.3898681 84.03854855 0.087934266 0.923309795
9.294306399
10.04396713
Balance Point
Qtotal heat loss 3697.696136 3613.657588 3529.619039 3445.580491 3361.541942 3277.503393 3193.464845 3109.426296 3025.387748 2941.349199 2857.310651 2773.272102 2689.233554 2605.195005 2521.156457 2437.117908 2353.079359 2269.040811 2185.002262 2100.963714 2016.925165 1932.886617 1848.848068 1764.80952 1680.770971 1596.732422 1512.693874 1428.655325 1344.616777 1260.578228 1176.53968 1092.501131 1008.462583 924.4240341 840.3854855 756.346937 672.3083884 588.2698399 504.2312913 420.1927428 336.1541942 252.1156457 168.0770971 84.03854855 0
8.931956614
140
141
Balance Points Graph (June – August) 4000
3500
3000
2500
Qtotal heat loss 2000
June July August
1500
1000
500
0 -1
4
9
14
19
24
29
34
39
44
49
139
Balance Points Graph – September – May
3000.00
2500.00
2000.00
Qtotal heat loss January February March April
1500.00
May September October November December
1000.00
500.00
0.00 -1
4
9
14
19
24
143
Degree-days & Carbon Emissions Description: Source: Station:
Celsius-based heating degree days for base temperatures at and around 17.5C Www.degreedays.net (using temperature data from www.wunderground.com) London / Heathrow Airport (0.46W, 51.48N) EGLL
Month starting 01/01/2009 01/02/2009 01/03/2009 01/04/2009 01/05/2009 01/06/2009 01/07/2009 01/08/2009 01/09/2009 01/10/2009 01/11/2009 01/12/2009
4.5 60 39 9 0 0 0 0 0 0 0 1 48
5 68 46 12 1 0 0 0 0 0 0 1 56
5.5 78 53 16 1 0 0 0 0 0 0 2 66
6 88 60 19 2 0 0 0 0 0 1 3 76
6.5 100 68 24 3 0 0 0 0 0 1 5 88
7 111 76 28 4 0 0 0 0 0 2 7 99
7.5 124 86 35 6 1 0 0 0 0 3 10 111
8 138 95 41 8 1 0 0 0 0 4 14 123
8.5 152 106 50 11 2 0 0 0 0 6 18 136
9 166 116 58 14 2 0 0 0 0 7 23 149
9.5 181 128 68 18 4 0 0 0 0 9 30 163
10 196 140 78 23 6 1 0 0 0 11 37 177
10.5 212 154 90 30 8 1 0 0 1 15 46 191
11 227 166 101 36 11 2 0 0 2 18 54 206
01/01/2010 01/02/2010 01/03/2010 01/04/2010 01/05/2010 01/06/2010 01/07/2010 01/08/2010 01/09/2010 01/10/2010 01/11/2010 01/12/2010
85 38 19 1 1 0 0 0 0 4 35 108
97 46 23 2 2 0 0 0 0 5 40 120
110 56 29 4 3 0 0 0 0 7 46 133
123 67 35 5 4 0 0 0 0 8 52 146
137 78 42 8 5 0 0 0 0 10 59 160
151 89 49 11 7 0 0 0 0 12 67 174
166 101 57 16 9 0 0 0 1 15 76 189
181 114 65 20 11 0 0 0 1 17 86 204
196 127 75 25 15 0 0 0 2 20 96 220
211 140 84 31 18 0 0 0 3 23 107 235
227 154 96 37 23 0 0 0 4 26 118 250
242 168 106 44 28 1 0 0 5 30 129 266
258 182 118 52 34 1 0 0 7 35 141 281
273 196 130 61 41 2 0 1 9 41 153 297
01/01/2011 01/02/2011 01/03/2011 01/04/2011 01/05/2011 01/06/2011 01/07/2011 01/08/2011 01/09/2011 01/10/2011 01/11/2011 01/12/2011
37 6 17 0 0 0 0 0 0 0 2 13
44 8 20 0 0 0 0 0 0 1 2 17
53 13 25 0 0 0 0 0 0 1 4 22
62 17 30 0 0 0 0 0 0 2 5 26
73 23 36 1 1 0 0 0 0 3 6 33
83 29 42 2 1 0 0 0 0 4 8 40
95 36 50 3 2 0 0 0 0 5 10 49
108 43 58 4 2 0 0 0 0 6 13 58
120 52 67 5 4 0 0 0 0 8 17 68
133 61 76 7 5 1 0 0 0 10 21 78
146 71 86 10 7 2 0 0 1 13 26 90
159 82 97 13 9 2 0 0 2 15 31 101
173 94 109 17 12 4 0 0 2 19 39 113
187 106 121 22 15 5 0 0 3 22 46 126
January February March April May June July August September October November December
DD -2009 227 116 35 2 0
DD - 2010 273 140 57 5 1
DD - 2011 187 61 50 0 0
Mean Average 229 106 47 2 0
-
-
-
-
0 6 46 206
0 20 141 297
0 8 39 126
0 11 75 210
Balance point 10.8051 9.0362 7.5963 5.9488 4.676
HLC 116.0710507 116.0710507 116.0710507 116.0710507 116.0710507
kWh 637.9264946 294.3561846 131.8567136 6.499978839 0.928568406
6.9197 8.4489 10.3063 11.1691
116.0710507 116.0710507 116.0710507 116.0710507
0 31.57132579 209.8564597 584.0695271
Total
1897.065253
Total Energy 1897.065253
Emissions factor 0.19
Predicted cost (3.15p per kWh) Property Area (m 2) Kwh/M 2
£59.75755546 183.61 10.33203667
Boiler efficiency 0.902
144
Carbon emissions (Kg CO2) 399.6035455
Energy consumption comparison - kWh/M2
Actual
10.33203667
PassivHaus
15 Previous New build PassivHaus
New build
Actual
55
Previous
165.6
0
20
40
60
80
100
120
140
160
180
Conclusion Shown above we can see the successful outcomes of our redesign of the dwelling. The actual kWh/m2 value sits at just over 10, with PassivHaus standards being stated at 15 and under. Compared to the previous value of 165.6, this is a vast improvement. Although not specifically designed as a PassivHaus in its form or orientation, the house does live up to many of the regulation values, working “passively” with it’s surrounding environment and occupants. Occupants play a key role in the post construction success of PassivHaus. An environmentally unaware occupant will produce significantly more carbon emissions through appliance gains, over ventilation and poor monitoring of solar gains (blinds). The concept behind “passive” house is to have a house, which involves minimal response or resistance, an environmentally aware occupant will be aware of this, and the resultant effect will be minimal carbon emissions. This concept could be further exemplified by the installation of live energy monitors, a feature we believe should be mandatory in every home. The success of PassivHaus isn’t only based on carbon emissions but at an economic level where the money saved from a reduction in energy bills is considered. The previous estimated energy bill P.A was calculated at £967.789 compared to the new value of £59.75. When this is considered over a significant cycle within the dwelling such as 15 years it amounts to £13620.585 saving from energy bills alone. However In many cases the cost of implementing PassivHaus strategies outweighs the benefits with the proportion of money saved in bills seeming very little in comparison to the installation costs. In some countries monetary reimbursement schemes exist to make the PassivHaus route seem more attractive a route the UK should potentially explore. With the inevitable increase in environmental pressures over the horizon the number of passive house designs in the UK can only increase, this will create a knock on effect as more architects and builders become aware and practised in this very stringent art of PassivHaus creation. Our re-design of a cavity wall based PassivHaus was very successful considering no previous site and design preparations were made. The calculations taken may have some small indescrepencies due to a certain level of estimation required, however with the installation of a MVHR system our calculation for Qventilation became considerable more accurate than previously with the dwelling. However the high cost of our re-design may make the proposed improvements financially unviable.
Equations
146