TENDER SUBMISSION FOR LONDON OFFICE BUILDINGS GROUP Report submitted as a part of K13IDM on 13/5/2015 4183047 | 4187823 | 4186893
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Tender Submission | K13IDM
EXECUTIVE SUMMARY Long Eaton Services Consultants have been tasked by London Office
of escape. The vertical transport system more than adequately serves
Buildings with designing the services for a new office block.
the building, obtaining an ‘excellent’ service standard.
The
proposed building stands 10 storeys tall, with 9 floors of open plan
Installing triple glazing and additional insulation reduced energy
offices. Heating, cooling and ventilation systems were to be specified,
consumption and carbon emissions by 21%. Though environmentally
whilst considering potential enhancements to the building’s performance.
sound, they are not financially viable, as it would take 50 years to break
The building’s vertical transport systems and fire protection were to be
even.
assessed to ensure the building complies with Approved Document B and Smaller savings of 1-2% could be attained by providing total solar shading
British Standards 5655-6.
and additional thermal mass. Due to their minimal capital costs, they It was decided that a VAV Air Conditioning System would best suit the
provide immediate financial gains.
needs of the building. Peak heating and cooling requirements were To achieve the greatest savings in energy consumption and carbon
determined as 482kW and 432kW respectively, with an annual energy
emissions, all proposed changes should be implemented simultaneously.
consumption of 1.16 GWh and carbon footprint of 305 tonnes p.a.
Not only will LOB see net financial benefits, but will also help minimise Inspection of the building’s fire exits found breaches of regulation;
their impact on the environment.
appropriate solutions have been devised incorporating additional means (249)
EXECUTIVE SUMMARY
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NOMENCLATURE Symbol
Definition
Unit
đ???
Air Change Rate
h−1
Q
Heat Gains
W
đ??•
Volume
m3
đ?‘š3 /đ?‘
f3
Intermittence factor
[dimensionless]
W/K
HDD
Number of heat degree days
[dimensionless]
Also : Flow Rate (distinguished in text) Îť A
Thermal Conductance Area
2
ṁ
Mass flow rate
W/m K
g
Moisture content
m
2
kg/s
U
U-value
φ
Lag
h
M
Mixing point
%
θ
Hour of incidence
h
RH
Relative humidity
%
f
Decrement Factor
[dimensionless]
h
Specific enthalpy
kJ/kg
Also Correction factor (distinguished in text)
[dimensionless]
β
Contact factor of cooling coil
G
G-Value
[dimensionless]
p
Pressure
Pa
T
Temperature
K or ℃
Âľ
Fan efficiency
%
Mean solar cooling load at incident hour
W/m2
t
Time
h
Also Height
m
u
Velocity
Ρ
Solar exposure ratio
%
C
Hueretic constant
W
Width
m
x
Throw
m
xs
Shadow x-component
m
L
Total lift flight
m
ys
Shadow y-component
m
v
Speed
R
Overhang
m
n
Lift capacity
[dimensionless]
n
Wall-solar azimuth angle
°
N
Number of lift cars
[dimensionless]
a
Altitude
°
RTT
Ď
Air density
kg/m3
Îś
c
Air specific heat capacity
W/kgK
V̇
Volume flow rate
H
NOMENCLATURE
m3 /s
iv
Round trip time Component loss factor
Kg/kg
[dimensionless]
m/s [dimensionless]
m/s
s [dimensionless]
CONTENTS 1 INTRODUCTION
2
2 BUILDING INFORMATION
4
2.1 Zoning 2.2 Occupancy 2.3 Building Fabric 3 EXTREME CONDITIONS: HEATING SEASON 3.1 3.2 3.3 3.4 3.5
5 7 8
10 10 11 12 13
4 EXTREME CONDITIONS: COOLING SEASON
16
5 BOILER PLANT 5.1 Sizing the Boiler 5.2 Annual Running Costs and Carbon Emissions 6 AIR CONDITIONING SYSTEM (ACS) 6.1 Sizing System 6.2 Air conditioning system specification 6.3 Annual Running Costs 7 VENTILATION
Design Criteria duct configuration Fans supply diffuser choice
8 SENSITIVITY ANALYSIS 8.1 Potential Changes 8.2 Comparison of Changes 8.3 Reccommendations
10
Casual Heat Gains Solar Heat Gains Fabric Losses Ventilation Losses Local Enviornmental Conditions
4.1 Fabric Losses 4.2 Solar Gains 4.3 Ventilation Heat Transfer
7.1 7.2 7.3 7.4
9 FIRE PROTECTION 9.1 9.2 9.3 9.4 9.5
17 18 20
Horizontal Escape Vertical Escape Compartmentalisation of spaces Protection of Ventilation Openings Location of Fire-fighting servces
10 VERTICAL TRANSPORT 10.1System Mechanics 10.2Firefighting Lifts 10.3Quality of service assessment
22 22 24 26 26 28 31
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42 42 43 44 46 46 48 48 49 50 52 53 55 55
11 CONCLUSIONS
58
12 BACK MATTER
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12.1References 12.2Appendix A 12.3Appendix B 12.4Appendix C
34
34 34 37 39
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FIGURES Figure 2-1: Proposed Building
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Figure 9-3: Entrance floor, not meeting maximum travel distances
47
Figure 2-2: Zoning arrangements
5
Figure 9-4: Entrance floor, not meeting maximum travel distances
47
Figure 2-3: Exploded Building Iso
6
Figure 9-5: Compartment floor configuration, meeting approved
Figure 2-4: Occupancy Schedule
7
document Bs guidelines.
49
Figure 3-1: Fabric heat transfer
11
Figure 9-6: Pipe sleeving, taken from Approved Document B, [12]
49
Figure 3-2: Graph to show ventilation and infiltration losses
13
Figure 9-7: ground floor sprinkler system
50
Figure 4-1:Internal Gains Schedule
16
Figure 9-8: Office floor sprinkler system
50
Figure 4-2: Effect of lag and decrement on heat transfer
17
Figure 10-1: Exploded View of Building Showing Lifts
52
Figure 4-3: Overhang providing solar shading on glazed surfaces (orange) 19
Figure 10-2: Plan of Lift Showing Dimensions around Car as given in CIBSE
Figure 4-4: Range of Ventilation heat transfer for each Month
20
Guide D 0
Figure 5-1: Graph showing pre-heat times prior to occupancy, [6]
22
Figure 10-3: Comparison of Side Opening and Two-Speed Centre Opening
53
Figure 5-2: Graph to show number of heating degree-days, CIBSE Guide A 24
Doors
53
Figure 6-1: Monthly peak sensible heat gains
26
Figure 10-4: Single Wrap Pulley System
54
Figure 6-2: Air Conditioning complete Psychometric Process
27
Figure 6-3: Fan Assisted VAV system schematic
29
Figure 7-1: Duct Layout in Plan
35
Figure 7-2: Supply Duct layout in Section
35
Figure 7-3: Supply Index Run
36
Figure 8-1: Comparison of changes
44
Figure 9-1: Typical office floor, not meeting maximum travel distances
47
Figure 9-2: Typical office floor, meeting maximum travel distances
47
FIGURES
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TABLES Table 2-1: Building Geometry
4
Table 5-3: Fuel Prices, taken from Table 12 SAP 2012, [4]
24
Table 2-2: Zone Dimensions Ground Floor
6
Table 6-1: Peak Cooling Loads
26
Table 2-3: Zone Dimensions Typical Floor
6
Table 6-2: Psychometric properties of air
27
Table 2-4: Zone Occupancy
7
Table 6-3: Factors to consider when specifying an ACS
28
Table 2-5: Fabric Properties
8
Table 6-4: VAV system components
29
Table 2-6: Wall and Glazing Areas
8
Table 6-5: Advantages and Disadvantages of a VAV system
30
Table 3-1: Casual Internal Heat Gains
10
Table 6-6: Three approaches to estimate ACS cooling load
31
Table 3-2: Fabric Properties
11
Table 7-1: Ventilation Requirements
34
Table 3-3: Equation 1 parameters
11
Table 7-2: Total extract for each sanitary zone
36
Table 3-4: Ventilation Requirements
12
Table 7-3: Pressure Drop over Index Run
37
Table 4-1: Internal Gains
16
Table 7-4: Equation Parameters
38
Table 4-2: Equation 4-1 parameters
17
Table 7-5: Fan and energy characteristics
38
Table 4-3: Material properties
17
Table 7-6: Supply Diffuser Sizing
39
Table 4-4: Equation 4-2 parameters
18
Table 8-1: U-value comparison of Part L requirement and ACEB Gold
Table 4-5: Glazing parameters
18
Standard
42
Table 4-6: Peak solar cooling loads
18
Table 8-2: Comparing performance of double glazing vs triple glazing
42
Table 4-7: Equation 4-3 and 4-4 parameters
19
Table 8-3: Effect of increasing thermal mass
43
Table 4-8: Effect of Shading on Peak Solar Cooling loads
20
Table 8-4: Comparison of changes
43
Table 4-9: Equation 4-5 parameters
20
Table 8-5: Recommendations
44
Table 5-1: Equation 5-1 Parameters
22
Table 9-1 Maximum travel distances, taken from Approved Document B,
Table 5-2: Building Specifications calculated in section 3.5
22
[12]
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Table 9-2: Number of routes required, taken from Approved Document B,
Table 12-6: Annual Energy Consumption and Carbon Emissions, using
[12]
46
data from SAAP Building Regulations 2010, Table 12.
Table 9-3: Minimum exit widths, Approved document B, [12]
48
Table 12-7: South Wall heat transfer (W) Example of Quasi-Dynamic Heat
Table 9-4: Compartment regulations, Approved document B, [12]
48
transfer calculation
VI
Table 9-5: Maximum sprinkler distances, BSEN pg 77 , [13], [14]
50
Table 12-8: Total Fabric heat transfer (W)
VII
Table 10-1: Lift Shaft Dimensions
52
Table 12-9: Ventilation Heat transfer (W)
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Table 10-2: Breakdown of Car Capacity
53
Table 12-10: West Glazing unshaded solar gain (W) Example of solar
Table 10-3: System specification
55
cooling load
Table 10-4: Lift Calculations for Quality of Service
55
Table 12-11: West glazing shaded solar gain (W) Example of solar cooling
Table 12-1: Weather data used for Heating Season Calculations, taken
V
IX
load
IX
from CIBSE Guide J, Table 5.36
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Table 12-12: Total Solar Gains accounting for shading (W)
X
Table 12-2: Fabric gains/Losses (Wall, Roof, Glazing)
II
Table 12-13: Total Sensible Heat transfer (W)
XI
Table 12-3: Total fabric gains/losses. (Wall, roof, glazing, Floor)
III
Table 12-14: Total pressure drop along pipes and method
XII
Table 12-4: Plant Sizing
IV
Table 12-15: Total Pressure loss calculations
XIII
Table 12-5: Heating Degree Days, taken from CIBSE Guide A, Table 2.23
IV
TABLES
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INTRODUCTION
Long Eaton Services Consultants would like to thank London Office
The primary aims of this report are:
Buildings for the invitation to apply for tender for designing the services
of their newly proposed office block.
To evaluate the thermal performance of the building to determine peak heating and cooling loads.
A requirement of the tender document was that consultants should design the heating, cooling and ventilation systems for the 10-storey
To appropriately size the building’s boiler and air conditioning systems capable of meeting these demands.
building.
To quantify a series of potential improvements to evaluate their economical and environmental feasibility.
It was also requested that the plans should be examined to identify any
potential issues that exist. Areas of particular concern were the fire-safety
To ensure that the building conforms to Approved Document B of the UK Building Regulations with regards to fire protection.
and vertical transportation systems that could potentially be in breach of
UK Building Regulations.
To ensure that the proposed vertical transport systems are capable of meeting the building’s requirements. (178)
INTRODUCTION
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BUILDING INFORMATION Table 2-1: Building Geometry
The building under investigation is a 10- storey office block that is situated in London at the junction between City Road and King George Street. Of the 10 storeys, floors one to nine are open plan offices, whilst the ground floor serves as an entrance foyer. There is also a basement in the building, and a services block on the roof. Since they both lie are outside of the thermal envelope, neither and are considered in this report.
Figure 2-1: Proposed Building
BUILDING INFORMATION
4
Parameter
Value
Unit
Height
37.8
m
Ground Floor to Ceiling
4.2
m
Typical Floor to Ceiling
3.6
m
Depth
19.7
m
Width
50.0
m
Volume
36674
m
3
Envelope Area
6450
m
2
Wall Area
5331
m
2
Roof Area
985
m
2
Ground Area
852
m
2
Exposed Floor
133
m
2
Surface Area: Volume
0.18
m
Usable Floor Space
9717
m
Floors
10
(dimensionless)
Ground Floors
1
(dimensionless)
Typical Floors
9
(dimensionless)
-1 2
2.1
ZONING
Each floor is subdivided into distinct thermal zones. The ground floor is dominated by a large entrance zone; with facilities located in the central core, see Table 2-2. There is a void in the rear of the building, which provides service access. The upper floors follow a similar pattern; with large occupied open plan office space, surrounding services and amenities, see Figure 2-2and Table 2-3.
Figure 2-2: Zoning arrangements
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Table 2-2: Zone Dimensions Ground Floor 2
3
Code
Zone
Width (m)
Depth (m)
Area (m )
Volume (m )
001
Entrance
50.0
19.7
689.8*
2897.2
002
Lobby
9.0
4.5
40.5
170.1
003
Male WC
3.0
4.5
13.5
56.7
004
Female WC
3.0
4.5
13.5
56.7
005
Circulation [W]
8.6
4.5
38.7
162.5
006
Circulation [E]
8.6
4.5
38.7
162.5
007
Lifts [W]
1.9
4.5
8.6
35.9
008
Lifts [E]
1.9
4.5
8.6
35.9
851.8
3577.6
Total
*Area defined as total floor area not accounted for in other zones inc. services void. Table 2-3: Zone Dimensions Typical Floor 2
3
Code
Zone
Width (m)
Depth (m)
Area (m )
Volume (m )
101
Office
50.0
19.7
793.8*
2857.5
102
Lobby
9.0
4.5
40.5
145.8
103
Male WC
7.5
4.5
33.8
121.5
104
Female WC
5.0
4.5
22.5
81.0
105
Circulation [W]
8.6
4.5
38.7
139.3
106
Circulation [E]
8.6
4.5
38.7
139.3
107
Lifts [W]
1.9
4.5
8.6
30.8
108
Lifts [E]
1.9
4.5
8.6
30.8
985.0
3546.0
Total
*Area defined as total floor area not accounted for in other zones Figure 2-3: Exploded Building Iso
BUILDING INFORMATION
6
2.2
Table 2-4: Zone Occupancy
OCCUPANCY
The occupancy for each zone in shown in Table 2 4. The total occupancy for the building is 722 people, only 11 of whom are most in the office. The occupancy profile is modelled on a typical 09:00 to 17:00 working day, see Figure 2-4. To simulate gradual arrival and departure of occupants it increases/decreases incrementally over the course of three
Proportion of peak Occupancy
hours. Occupancy also drops to have capacity during lunch hours.
1 0.75 0.5 0.25
2
Code
Zone
Area (m )
Occupancy Density 2 (m /person)
Occupancy (people)
001
Entrance
689.8
0*
0
002
Lobby
40.5
4†
11
003
Male WC
13.5
0
0
004
Female WC
13.5
0
0
005
Circulation [W]
38.7
0
0
006
Circulation [E]
38.7
0
0
007
Lifts [W]
8.6
0
0
008
Lifts [E]
8.6
0
0
101
Office
793.8
10
79
102
Lobby
40.5
0
0
103
Male WC
33.8
0
0
104
Female WC
22.5
0
0
105
Circulation [W]
38.7
0
0
106
Circulation [E]
38.7
0
0
107
Lifts [W]
8.6
0
0
108
Lifts [E]
8.6
0
0
*Occupancy specified as 0 as occupancy in entrance specified under lobby
0
1 2 3 4 5 6 7 8 9 101112131415161718192021222324
†Occupancy Density specified using CIBSE guide A Table 6.2 for a Hotel Lobby [1]
Hour number (hours)
Figure 2-4: Occupancy Schedule
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2.3
Table 2-6: Wall and Glazing Areas
BUILDING FABRIC
The building is assumed to be thermally lightweight. The dimensions and U-values for each element of the building fabric are shown in Table 2-5. The U-values comply to the limiting standards given in building
Wall
Glazing Ratios
Wall total area (m2)
Wall area (m2)
Glazing Area (m2)
Wall N
61%
1814
713
1101
Wall E
34%
745
488
256
Wall S
61%
1890
743
1147
Wall W
34%
745
488
256
regulations document L2 [2]. The wall and glazing areas for each façade are shown in Table 2-6 Table 2-5: Fabric Properties Surface
Construction
Limiting U2 Value (W/m K)
INFILTRATION
Surface Area
The infiltration rate is set at the standard value of 0.4đ?‘Žđ?‘?ℎ−1 throughout
2
(m ) Roof
Waterproof roof covering, 35mm polyurethane insulation, vapour control layer, 19mm timber decking, unventilated airspace, 12.5 mm plasterboard
0.25
105mm brick, 50mm airspace, 19mm plywood sheathing, 95mm studding, 12.5mm plasterboard.
0.35
10 m carpet, 19mm timber on100 mm joists, 100mm mineral fibre insulation between joists, 12mm cementitious building board on underside.
0.25
Glazing
Double Glazing in aluminium frames
2.2
2762
Vehicle Access Doors
Metal roller doors
1.5
138
Wall
Floor
BUILDING INFORMATION
the building [1]. The resulting air permeability is 2.17đ?‘š3 /â„Ž/đ?‘š2 *. This
985
outperforms best practice guidelines, predominantly due to the large surface are to volume ratio of the building. In reality, the air leakage
2432
would likely be higher, closer to 5đ?‘š3 /â„Ž/đ?‘š2 . 985
(347)
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EXTREME CONDITIONS: HEATING SEASON Table 3-1: Casual Internal Heat Gains
The building’s thermal performance is analysed to determine its heating load and size its boiler. Heat is lost via convection due to ventilation and
Zone
Floor Area 2 (m )
QOcc, sensible (W)
QLighting, sensible (W)
QEquip, sensible (W)
Entrance Lobby Sanitary Accom. ♂ Sanitary Accom. ♀ Circulation [W] Circulation [E] Lifts [W] Lifts [E] Office Lobby Sanitary Accom. ♂ Sanitary Accom. ♀ Circulation [W] Circulation [E] Lifts [W] Lifts [E] Total
689.8 40.5 13.5
825 -
10347 405 -
10347 405 -
Total Sensible Gains (W) 10347 405 -
13.5
-
-
-
-
38.7
-
-
-
-
38.7
-
-
-
-
8.55 8.55 793.75 40.5 33.75
5530 -
7937 405 -
7937 405 -
7937 405 -
22.5
-
-
-
-
38.7
-
-
-
-
38.7
-
-
-
-
8.55 8.55
50595
85834
109181
245611
conduction from the buildings fabric. 3.1
CASUAL HEAT GAINS
People, lighting and equipment generate internal heat gains, calculated using CIBSE Guide A [1] for each zone totalling 24.6 kW, see Table 3-1. Though not accounted for in plant sizing, casual heat gains effectively reduce the heating requirement of the building and boiler. 3.2
SOLAR HEAT GAINS
Solar gains are not considered when assessing the building’s heating load. This is because the peak-heating load is calculated for the worst-case scenario, no solar exposure. Building form and orientation could be considered to optimise the influence of solar gains.
EXTREME CONDITIONS: HEATING SEASON
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3.3
Table 3-3: Equation 1 parameters
FABRIC LOSSES Symbol đ?œ† A U
The performance of the building’s thermal envelope determines the rate of fabric heat lost/gained. The rate of heat lost per unit of temperature
Parameter Thermal Conductance Area U-Value
Unit W/K 2 m 2 W/m K
difference through each surface is calculated using equation 3-1. đ?œ† = đ?‘ˆđ??´ [3-1]
Example calculation: Total thermal conductance ÎŁđ?‘ˆđ??´ = (0.25 đ?‘Ľ 985) + (0.35 đ?‘Ľ 2432) + (0.25 đ?‘Ľ 985) + (2.2 đ?‘Ľ762) + (1.5đ?‘Ľ138) = 7626 W/K
Table 3-2: Fabric Properties Surface
Limiting U-Value 2 (W/m K)
Floor Area
Roof
0.25
985
246
Wall
0.35
2432
851
Floor
0.25
985
246
Glazing
2.2
2762
6075
Vehicle Access Doors
1.5
138
207
Total
Thermal Conductance (W/K)
2
(m )
Figure 3-1: Fabric heat transfer
7626
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3.4
VENTILATION LOSSES
Ventilation requirements for each zone were approximated using table Example Calculation: Ventilation requirements for the Office 1.5, CIBSE Guide A [1], seen in Table 3-4. Ventilation provides fresh air to
Ventilation: 79 people x 10 L/s = 790 L/s = 0.79 m3 /s
the occupants, removing pollutants. Infiltration, via adventitious
Infiltration: 0.4 ađ?‘?ℎ−1 x 2857.5 m3 = 1143 m3 /h = 0.3175 m3 /s
openings, has also been considered. Table 3-4: Ventilation Requirements Zone
Floor Area (đ?’Žđ?&#x;? )
Volume (đ?’Žđ?&#x;‘ )
Entrance
689.8
2897.16
0
Lobby
40.5
170.1
11
Male WC
13.5
56.7
0
Female WC
13.5
56.7
0
Circulation [W]
38.7
162.54
Circulation [E]
38.7
162.54
Lifts [W]
8.55
Lifts [E]
8.55
Office Lobby
Total ventilation rate per zone (L/s)
Total ventilation rate per zone (đ?’Žđ?&#x;‘ /s)
Infiltration (ađ?’„đ?’‰âˆ’đ?&#x;? )
Infiltration rate (đ?’Žđ?&#x;‘ /h)
Infiltration rate (đ?’Žđ?&#x;‘ /s)
0
0.4
1158.864
0.321906667
110
0.11
0.4
68.04
0.0189
0
0
0.4
22.68
0.0063
0
0
0.4
22.68
0.0063
0
0
0
0.4
65.016
0.01806
0
0
0
0.4
65.016
0.01806
35.91
0
0
0
0.4
14.364
0.00399
35.91
0
0
0
0.4
14.364
0.00399
793.75
2857.5
79
0.79
0.4
1143
0.3175
40.5
145.8
0
0
0
0.4
58.32
0.0162
Male WC
33.75
121.5
0
0
0
0.4
48.6
0.0135
Female WC
22.5
81
0
0
0
0.4
32.4
0.009
Circulation [W]
38.7
139.32
0
0
0
0.4
55.728
0.01548
Circulation [E]
38.7
139.32
0
0
0
0.4
55.728
0.01548
Lifts [W]
8.55
30.78
0
0
0
0.4
12.312
0.00342
Lifts [E]
8.55
30.78
0
0
0
0.4
12.312
0.00342
Total
EXTREME CONDITIONS: HEATING SEASON
Occupancy (people)
Ventilatio n Rate Required per person (L/s)
Total ventilation rate per person per zone (L/s)
10
110
0
10
790
35491
790
7220
12
7.22
3.94
Ventilation requirements state that 7.22 đ?‘š3/s of air is needed for the
Example Calculation: Total Air Change Rate for whole building
building. With infiltration set at 0.4 ađ?‘?ℎ−1 per zone, it results in a net loss
7.22 đ?‘š3 /s + 3.9đ?‘š3 /s = 11.2 đ?‘š3 /s x 3600 = 40188.6 đ?‘š3 /h
of 3.9đ?‘š3 /s of air. Figure 3-2 shows infiltration making up 35% of the
40188.6 đ?‘š3 /h / 35491 40188.6 đ?‘š3 = 1.13 đ?’‚đ?’„đ?’‰âˆ’đ?&#x;?
ventilation losses. 3.5
LOCAL ENVIORNMENTAL CONDITIONS
The annual external temperatures in London for each hour of the day, each month of the year are used to calculate the buildings peak-heating
35% Ventilation
load.
Appendix B details the weather data. The internal design
Infiltration
temperatures for winter and summer, were 22Ëš and 23Ëš respectively,
65%
taken from CIBSE Guide A, table 1.5. (272)
Figure 3-2: Graph to show ventilation and infiltration losses
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EXTREME CONDITIONS: HEATING SEASON
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EXTREME CONDITIONS: COOLING SEASON
Casual Heat Gains (kW)
The internal gains are estimated using heat gain densities specific to a zone’s function (Table 6.3, CIBSE Guide A [1]) and are compiled in Table 4-1.
The gains operate proportionally to the occupancy schedule.
300
Sensible Latent
200 100
0 Hour
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Table 4-1: Internal Gains
Zone
Entrance Lobby Sanitary Accom. ♂ Sanitary Accom. ♀ Circulation [W] Circulation [E] Lifts [W] Lifts [E] Office Lobby Sanitary Accom. ♂ Sanitary Accom. ♀ Circulation [W] Circulation [E] Lifts [W] Lifts [E]
Floor 2 Area (m )
Occupancy (persons)
689.8 40.5 13.5 13.5 38.7 38.7 8.55 8.55 793.75 40.5 33.75 22.5 38.7 38.7 8.55 8.55
0 11 0 0 0 0 0 0 79 0 0 0 0 0 0 0
Sensible heat gains per person (W) 75 70 -
Latent heat gains per person (W) 55 45 -
Figure 4-1:Internal Gains Schedule
Lighting gain, Area Weighted 2 (W/m ) 15 10 10 10 -
Total
EXTREME CONDITIONS: COOLING SEASON
16
Equipment gains, Area Weighted 2 (W/m ) 5 15 5 -
QOcc, sensible (W) 825 5530 -
QOcc, latent (W) 605 3555 -
QLighting, sensible (W) 10347 405 7937 405 -
QEquip, sensible (W) 0 202 0 0 0 0 0 0 11906 202 0 0 0 0 0 0
Total Sensible Gains (W) 10347 1432 0 0 0 0 0 0 25374 608 0 0 0 0 0 0
Total Latent Gains (W) 0 605 0 0 0 0 0 0 3555 0 0 0 0 0 0 0
50595
50595
85834
109181
245611
32600
4.1
Table 4-2: Equation 4-1 parameters
FABRIC LOSSES Symbol
Fabric losses are calculated using quasi-dynamic calculations (equation 4-
đ?‘„đ?œƒ+đ?œ‘
1) that take into account both a time lag and decrement in the transfer of heat through the building’s fabric, (Figure 4-2).
These values are
đ?‘„đ?œƒ+đ?œ‘ = đ??´đ?‘ˆ(đ?‘‡đ?‘’đ?‘š − đ?‘‡đ?‘&#x;đ?‘œđ?‘œđ?‘š ) + đ??´đ?‘ˆ(đ?‘‡đ?‘’0 − đ?‘‡đ?‘’đ?‘š )đ?‘“
[4-1]
Unit
Heat transfer at time đ?‘Ą = đ?œƒ + đ?œ‘
đ?‘Š
đ??´
Area
đ?‘š2
đ?‘ˆ
U-value
đ?œ‘
Lag
â„Ž
đ?œƒ
Hour of incidence
â„Ž
đ?‘“
Decrement Factor
[đ?‘‘đ?‘–đ?‘šđ?‘’đ?‘›đ?‘ đ?‘–đ?‘œđ?‘›đ?‘™đ?‘’đ?‘ đ?‘ ]
approximated using construction of comparable performance in table 3.49 CIBSE guide A.
Parameter
đ?‘Š/đ?‘š2 đ??ž
���
Mean sol-air temperature
℃
��0
Room air temperature
℃
���
Sol-air temperature at time đ?‘Ą = đ?œƒ
℃
Table 4-3: Material properties Surface
Figure 4-2: Effect of lag and decrement on heat transfer
Example Calculation – Transfer through West Wall on June 21st at 17:00 For a west facing light coloured wall đ?‘‡đ?‘’0 = 19.2 & đ?‘‡đ?‘’đ?‘š = 22.5 , đ?‘ đ?‘˘đ?‘šđ?‘šđ?‘’đ?‘&#x; đ?‘‡đ?‘&#x;đ?‘œđ?‘œđ?‘š = 23 [2]. đ?‘„17:00 = 488 Ă— 0.35(22.5 − 23) + 488 Ă— 0.35(19.2 − 22.5) Ă— 0.21 đ?‘„17:00 = −204đ?‘Š
2
2
U-Value (W/m K)
Area (m )
f
φ
Colour
Wall North
0.35
713
0.21
9
Light
Wall East
0.35
488
0.21
9
Light
Wall South
0.35
743
0.21
9
Light
Wall West
0.35
488
0.21
9
Light
Glazing North
2.20
1101
-
0
-
Glazing East
2.20
256
-
0
-
Glazing South
2.2
1147
-
0
-
Glazing West
2.2
256
-
0
-
Roof
0.25
985
0.15
10
Dark
Exposed Floor
0.25
133
0.15
9
Light
Access Doors (delivery void)
1.5
138
1.00
1
Light
Calculations for hourly heat transfers for all surfaces can be found in Appendix B.
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4.2
Table 4-4: Equation 4-2 parameters
SOLAR GAINS
Solar gains though an un-shaded glazed surface are calculated using Equation 4-2, where each parameter is defined by the building’s location (London), response factor (fast), and the window’s glazing type and orientation (Table 4-5). đ?‘„đ?‘ đ?‘œđ?‘™đ?‘Žđ?‘&#x; = đ??´ Ă— đ??ť Ă— đ??ş Ă— đ?‘“
Symbol
Parameter
Unit
đ?‘„đ?‘ đ?‘œđ?‘™đ?‘Žđ?‘&#x;
Solar heat gain
đ?‘Š
đ??´
Area
đ?‘š2
đ??ş
G-Value
[đ?‘‘đ?‘–đ?‘šđ?‘’đ?‘›đ?‘ đ?‘–đ?‘œđ?‘›đ?‘™đ?‘’đ?‘ đ?‘ ]
đ?‘“
Correction factor
[đ?‘‘đ?‘–đ?‘šđ?‘’đ?‘›đ?‘ đ?‘–đ?‘œđ?‘›đ?‘™đ?‘’đ?‘ đ?‘ ]
đ??ť
Mean solar cooling load at incident hour
đ?‘Š/đ?‘š2
Table 4-5: Glazing parameters
[4-2] Window
2
Azimuth (°)
Area (m )
Glazing type
G
f
Example calculation – East façade glazing at 14:30 on September 4th
Glazing North
0
1101
Clear/reflective
0.41[3]
0.50 [3]
For an East facing surface in SE England at 14:30 on Sep 4th, đ??ť is 132W/ m2 [3].
Glazing East
90
256
Clear/reflective
0.41
0.50
Glazing South
180
1147
Clear/reflective
0.41
0.50
Glazing West
270
256
Clear/reflective
0.41
0.50
14:30,đ?‘†đ?‘’đ?‘? 4đ?‘Ąâ„Ž đ?‘„đ?‘ đ?‘œđ?‘™đ?‘Žđ?‘&#x;, đ??¸đ?‘Žđ?‘ đ?‘Ą
2
2
= 256m Ă— 132đ?‘Š/đ?‘š Ă— 0.41 Ă— 0.50 14:30,đ?‘†đ?‘’đ?‘? 4đ?‘Ąâ„Ž đ??¸đ?‘Žđ?‘ đ?‘Ą
đ?‘„đ?‘ đ?‘œđ?‘™đ?‘Žđ?‘&#x;,
Table 4-6: Peak solar cooling loads
= 6927W Glazing
The shortcoming using this approach is that no solar cooling loads are
Peak solar cooling load (W)
Date
Time
154495
April 28th
12:30
of which North
34772
June 21st
12:30 and 13:30
of which East
30432
June 21st
08:30
of which South
133124
November 4th
12:30
of which West
30379
June 21st
17:30
Ground Floor
35313
April 28th
12:30
Typical Floor
13242
April 28th
12:30
Whole Building
provided outside of 07:30 to 17:30. This is not too significant as they would fall outside of the office’s operational times. They would also be far smaller than solar gains inside the working day, making it highly improbable that they would affect the peak cooling load of the building.
Calculations for full hourly solar gains for all glazed surfaces can be found in Appendix B.
EXTREME CONDITIONS: COOLING SEASON
18
SOLAR SHADING
Example – Window on South façade glazing at 14:30 on September 4th
Recesses cause solar shading on the building’s windows, the extent of
đ?‘„đ?‘˘đ?‘›đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ = 103253đ?‘Š, đ?‘„đ?‘ đ?‘œđ?‘&#x;đ?‘Ąâ„Ž = 18515đ?‘Š, đ?‘Ž = 37°, đ?‘› = 49°, đ?‘Šđ?‘Š = 3.85đ?‘š, đ??ťđ?‘¤ = 1.50đ?‘š and đ?‘… = 0.5đ?‘š.
which is calculated using equation 4-3. The portion of glazing in shade
đ?‘Ľđ?‘ = 0.5đ?‘š Ă— tan 49° = 0.58đ?‘š, đ?‘Śđ?‘ = 0.5đ?‘š Ă— sec 49° Ă— tan 37° = 0.57đ?‘š
receives no direct sunlight and is recalculated as a north facing window. Ρ= Ρ= Where:
(đ?‘Šđ?‘¤ − đ?‘Ľđ?‘ ) Ă— (đ??ťđ?‘¤ − đ?‘Śđ?‘ ) đ?‘Šđ?‘¤ Ă— đ??ťđ?‘¤
[4-3]
(3.85 − 0.58) Ă— (1.5 − 0.57) = 53% 3.85 Ă— 1.50
Therefore the cooling load accommodating for shading is: đ?‘„đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ = 53% Ă— 103253đ?‘Š + 47% Ă— 18515đ?‘Š = 63426đ?‘Š
đ?‘Ľđ?‘ = đ?‘… Ă— tan đ?‘› and đ?‘Śđ?‘ = đ?‘… Ă— sec đ?‘› Ă— tan đ?‘Ž
Table 4-7: Equation 4-3 and 4-4 parameters
The adjusted solar gain through a window is: đ?‘„đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ = đ?œ‚ Ă— đ?‘„đ?‘˘đ?‘›đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ + (1 − đ?œ‚) Ă— đ?‘„đ?‘ đ?‘œđ?‘&#x;đ?‘Ąâ„Ž
Symbol
[4-4]
Parameter
Unit
đ??´
Area
đ?‘š2
đ?œ‚
Solar exposure ratio
%
��
Window width
đ?‘š
đ??ťđ?‘¤
Window Height
đ?‘š
đ?‘Ľđ?‘
Shadow x-component
đ?‘š
đ?‘Śđ?‘
Shadow y-component
đ?‘š
đ?‘…
Overhang
đ?‘š
đ?‘›
Wall-solar azimuth angle
°
đ?‘Ž
Altitude
°
đ?‘„đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ đ?‘„đ?‘˘đ?‘›đ?‘ â„Žđ?‘Žđ?‘‘đ?‘’đ?‘‘ Figure 4-3: Overhang providing solar shading on glazed surfaces (orange)
đ?‘„đ?‘ đ?‘œđ?‘&#x;đ?‘Ąâ„Ž
19
Solar gain of window accounting for shading
đ?‘Š
Solar gain of window without shading
đ?‘Š
Solar gain of identical window facing North
đ?‘Š
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This shading only results in a 1% reduction in solar gain. It would be
4.3
VENTILATION HEAT TRANSFER
advisable to implement shading devices that can provide total shading,
Combined losses due to purpose provided and adventitious ventilation is
which would result in a reduction in peak solar gain by as much as 75%.
calculated using equation 4-5 using the air flow rates defined earlier. đ?‘„đ?‘Łđ?‘’đ?‘›đ?‘Ą = đ?œŒ Ă— đ?‘? Ă— đ?‘‰Ě‡ Ă— (đ?‘‡đ?‘&#x;đ?‘œđ?‘œđ?‘š − đ?‘‡đ?‘Žđ?‘–đ?‘&#x; )
Table 4-8: Effect of Shading on Peak Solar Cooling loads Glazing
Whole Building
[4-5]
Peak solar cooling load, un-shaded (W)
Peak solar cooling load, with shading adjustment (W)
Reduction due to shading (%)
154495
153093
0.91%
�����
Air density
đ?‘˜đ?‘”/đ?‘š3 đ?‘Š/đ?‘˜đ?‘”đ??ž
Table 4-9: Equation 4-5 parameters Symbol
Parameter
Unit đ?‘Š
Heat loss due to ventilation
North
34772
34772
0.00%
đ?œŒ
East
30432
30218
0.70%
đ?‘? đ?‘‰Ě‡
Air specific heat capacity
đ?‘‡đ?‘Žđ?‘–đ?‘&#x;
External air temperature
đ??ž
Room temperature
đ??ž
133124
132787
0.25%
West
30379
30379
0.00%
Ground Floor
35313
34993
0.91%
Typical Floor
13242
13122
0.91%
đ?‘‡đ?‘&#x;đ?‘œđ?‘œđ?‘š
đ?‘š3 /đ?‘
50 Ventilation Heat Transfer (kW)
South
Volume flow rate
0 -50 -100 -150 -200
-250 -300 -350
Jan Feb Mar Apr May Jun
Jul
Aug Sep Oct Nov Dec
Figure 4-4: Range of Ventilation heat transfer for each Month
(277)
EXTREME CONDITIONS: COOLING SEASON
20
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5
BOILER PLANT
5.1
SIZING THE BOILER
Table 5-1: Equation 5-1 Parameters
The building’s boiler can be sized using the steady state equation
Symbol
Parameter
Unit
đ??”
U-Value
�/�2 K
�
Area
đ?‘š2
đ?‘ľ
Air Change Rate
ℎ−1
đ?‘˝
Building Volume
đ?‘š3
đ?‘ťđ??ź
Design Inside Temperature
ËšC
đ?‘ťđ?’…đ?’?
Design Outside Temperature
ËšC
(equation 5-1). Heating systems are designed to heat the building when unoccupied with no casual/solar gains, see Figure 5-1
Using the internal design temperatures and weather data from CIBSE Guide J, the annual energy demand is calculated using equation 5-1 and Table 5-2. Table 5-2: Building Specifications calculated in section 3.5
Figure 5-1: Graph showing pre-heat times prior to occupancy, [6]
Qd = [ÎŁ đ?‘ˆđ??´ + 0.33đ?‘ đ?‘‰](đ?‘‡đ?‘– − đ?‘‡đ?‘‘đ?‘œ )
BOILER PLANT
[5-1]
22
���
N
V
(W/K)
(đ?’‚đ?’„đ?’‰âˆ’đ?&#x;? )
(đ?’Žđ?&#x;‘ )
7626
1.13
36674
hours of occupancy and two additional hours of pre-heating, requiring an
The peak-heating load occurs in December between 06:00 and 07:00.
đ?‘“3 value of 1.2 . Example Calculation: Peak heating load
Qd = 7626 + 0.33 đ?‘Ľ 1.13 đ?‘Ľ 36674đ?‘‰](22−— 0.4)
Example Calculation: Actual Peak Heating load
= -482075 W of heat energy lost
1.2 x 482075 = 578490 W
Peak Heating load = 482075 W = 482 kW
= 578 kW
Heating systems are designed to meet the maximum heating load likely to occur. However, additional capacity is needed to overcome thermal inertia so that the building may reach an operational temperature quickly. The required boiler capacity is calculated by applying an intermittence factor,đ?‘“3,that takes into account the thermal response of the building and the hours of plant operation (equation 5-3). đ?‘ƒđ?‘’đ?‘Žđ?‘˜ â„Žđ?‘’đ?‘Žđ?‘Ąđ?‘–đ?‘›đ?‘” đ?‘™đ?‘œđ?‘Žđ?‘‘ = đ?‘“3 đ?‘Ľ đ?‘ đ?‘?đ?‘Žđ?‘?đ?‘’ â„Žđ?‘’đ?‘Žđ?‘Ą đ?‘™đ?‘œđ?‘Žđ?‘‘ [5-3] Table 1.11 in CIBSE Guide B, [3], recommends plant size ratios according to heating periods. The boiler must operate for 16 hours, to serve the 14
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5.2
ANNUAL RUNNING COSTS AND CARBON EMISSIONS
Equation 5-4 shows the amount of heat lost in one year.
The annual energy consumption of the heating system is calculated to
đ?‘„đ?‘Ś = 24(ÎŁ đ?‘ˆđ??´ + 0.33đ?‘ đ?‘‰)HDD [5-4]
estimate its running costs and carbon emissions. This is done by Example Calculation: Heat lost in one year
estimating the number of heating degree-days for which the external
�� = 24(7626 + 0.33 � 1.13 � 36674�)1936
temperature is below a base temperature, 15.5ËšC taken from CIBSE guide
= 988504 kWh of energy lost
A[1]. Figure 5-2 shows the HDD for London for an average year.
Number of Heating Degree Days
Table 5-3 states the costs and carbon emissions per kWh. 350 Table 5-3: Fuel Prices, taken from Table 12 SAP 2012, [4]
300 250
Fuel
Unit price (p/kWh)
Emissions (kg CO2 per kWh)
200
Mains Gas
3.48
0.216
150 100
Example Calculation: Annual Cost
50 0
= 988 504 x 3.48=ÂŁ34,399 p.a Example Calculation: Annual carbon emissions = 988 504 x 0.216 = 213 516 kg of carbon
Months of the Year
= 214 tonnes CO2 (245)
Figure 5-2: Graph to show number of heating degree-days, CIBSE Guide A
BOILER PLANT
24
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6
AIR CONDITIONING SYSTEM (ACS)
6.1
SIZING SYSTEM
AIR PROPERTIES
The ACS must be capable of offsetting both the peak sensible and latent
The sensible cooling load is used in conjunction with equation 6-1 to
heat gains in the building, coinciding at 14:00- 15:00 on August 4th.
determine the mass flow rate of supply air. đ?‘„đ?‘ đ?‘’đ?‘›đ?‘ đ?‘–đ?‘?đ?‘™đ?‘’ = đ?‘šĚ‡ Ă— đ?‘? Ă— Δđ?‘‡đ?‘…−đ?‘†
Table 6-1: Peak Cooling Loads Type
Load
Date
Time
Sensible
443.0kW
August 4th
14:00 – 15:00
Latent
32.6kW
Every day
9:00 – 13:00 and 14:00 – 17:00
[6-1]
To calculate the mass flow rate the temperature difference between the supply and room ( Δđ?‘‡đ?‘…−đ?‘† ) must be specified, in this case as 9°đ??ś , recommended by Roy Jones of Gilberts [5].
500 Sensible 443.0 kW
Peak Heat Gain (kW)
400
Higher values of đ?›Ľđ?‘‡đ?‘…−đ?‘† may be used, reducing the required air supply rate. This may be
Latent
necessary if the diffusers specified are incapable of meeting design requirements at higher air supply velocities.
300
đ?‘šĚ‡ = đ?‘„đ?‘ đ?‘’đ?‘›đ?‘ đ?‘–đ?‘?đ?‘™đ?‘’ /(đ?‘? Ă— Δđ?‘‡đ?‘…−đ?‘† )
200
đ?‘šĚ‡ = 443.0đ?‘˜đ?‘Š/(1.02đ?‘˜đ??˝/đ?‘˜đ?‘”đ??ž Ă— 9°đ??ś) = 48.3đ?‘˜đ?‘”/đ?‘
100 0
To find the properties of air at the supply point of the system, both
32.6kW
Jan
Feb Mar Apr May Jun
Jul
Aug Sep
Oct Nov Dec
đ?‘‡đ?‘‘đ?‘&#x;đ?‘Ś đ?‘?đ?‘˘đ?‘™đ?‘? and đ?‘…đ??ť must be fixed. đ?‘‡đ?‘‘đ?‘&#x;đ?‘Ś đ?‘?đ?‘˘đ?‘™đ?‘? is calculated as đ?‘‡đ?‘…,đ?‘‘đ?‘? − ∆đ?‘‡đ?‘…−đ?‘†
Figure 6-1: Monthly peak sensible heat gains
AIR CONDITIONING SYSTEM (ACS)
(23 − 9 = 14°đ??ś) whilst RH is pre-set at a typical value of 95% [6].
26
The room air’s properties can be found by using đ?‘‡đ?‘… combined with the room moisture content (đ?‘”đ?‘&#x; ), calculated with the building’s latent gains: đ?‘„đ?‘™đ?‘Žđ?‘Ąđ?‘’đ?‘›đ?‘Ą = đ?‘š ̇ Ă— đ??ż Ă— Δđ?‘”đ?‘…−đ?‘†
∴ Δđ?‘”đ?‘…−đ?‘† = đ?‘„đ?‘™đ?‘Žđ?‘Ąđ?‘’đ?‘›đ?‘Ą /đ?‘šĚ‡đ??ż
Δđ?‘”đ?‘…−đ?‘† = 32.6đ?‘˜đ?‘Š/(48.3đ?‘˜đ?‘”/đ?‘ Ă— 2450đ?‘˜đ??˝/đ?‘˜đ?‘”) = 0.00027đ?‘˜đ?‘”/đ?‘˜đ?‘” Allowing for calculation of đ?‘”đ?‘… = đ?‘”đ?‘† + Δđ?‘”đ?‘…−đ?‘† đ?‘”đ?‘… = 0.00946 + 0.00027 = 0.009743đ?‘˜đ?‘”/đ?‘˜đ?‘” CONDITIONING PROCESS The ACS in the building uses recirculation to reduce energy consumption. Figure 6-2: Air Conditioning complete Psychometric Process
To find the mixing point: ̇ ̇ đ?‘€ = 100% − đ?‘‰đ?‘“đ?‘&#x;đ?‘’đ?‘ â„Ž đ?‘Žđ?‘–đ?‘&#x; /đ?‘‰đ?‘?đ?‘œđ?‘œđ?‘™đ?‘–đ?‘›đ?‘” 7.22đ?‘š3 /đ?‘ = 100% − = 81.9% 39.8đ?‘š3 /đ?‘
Table 6-2: Psychometric properties of air Parameter
Symbol
Unit Outside
Where the volume flow rate of cooling air (đ?‘‰Ě‡đ?‘?đ?‘œđ?‘œđ?‘™đ?‘–đ?‘›đ?‘” ) is calculated from the mass flow rate (đ?‘šĚ‡) derived above, using the specific volume of air (đ?‘Ł ) at the supply. đ?‘‰Ě‡đ?‘?đ?‘œđ?‘œđ?‘™đ?‘–đ?‘›đ?‘” = đ?‘šĚ‡ Ă— đ?‘Ł = 47.1đ?‘˜đ?‘”/đ?‘ Ă— 0.825đ?‘š3 /đ?‘˜đ?‘” = 7.22đ?‘š3 /đ?‘
Air at Point: Supply Room
Mixing
Dry Bulb Temperature
đ?‘‡đ?‘‘đ?‘&#x;đ?‘Ś đ?‘?đ?‘˘đ?‘™đ?‘?
°đ??ś
25.8*
14.0
23.0â€
23.5
Wet bulb Temperature
đ?‘‡đ?‘¤đ?‘’đ?‘Ą đ?‘?đ?‘˘đ?‘™đ?‘?
°đ??ś
16.7*
13.8
17.3
17.50
Relative Humidity
đ?‘…đ??ť
%
39.3%*
95.0%
55.0%
55.5%
Specific Enthalpy
â„Ž
đ?‘˜đ??˝/đ?‘˜đ?‘”
46.6*
38.0
47.6
49.0
Moisture Content
đ?‘”
đ?‘˜đ?‘”/đ?‘˜đ?‘”
0.00813*
0.00946
0.009743
0.00944
th
* Obtained from CIBSE Guide J design day data, August 4 14:00-15:00
27
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APPARATUS DEW POINT
6.2
The Apparatus Dew Point (ADP) of the cooling coil is marked on Figure 6-2
Natural ventilation is the preferred method of cooling a building for
at 13.3°C.
environmental and financial reasons.
The contact factor of the cooling coil can also be �→�
AIR CONDITIONING SYSTEM SPECIFICATION
However, natural ventilation
cannot disperse as much heat as mechanical systems. CIBSE recommend
determined đ?›˝ = đ?‘€â†’đ??´đ??ˇđ?‘ƒ = 0.92.
any buildings with sensible gains of over 40đ?‘Š/đ?‘š2 to employ mechanical PLANT SIZING
ACS’s. The building’s sensible gains are 44.4�/�2 , implying it requires a
To ensure the ACS can cool the building if the cooling load were ever to mechanical cooling system. exceed the peak design load, a Plant Size Ratio (đ?‘ƒđ?‘†đ?‘…) is employed, at a Table 6-3: Factors to consider when specifying an ACS
typical value of 1.2.
đ?‘„đ?‘?đ?‘œđ?‘œđ?‘™đ?‘–đ?‘›đ?‘” = đ?‘šĚ‡ Ă— (â„Žđ?‘€ − â„Žđ?‘† ) = 48.3đ?‘˜đ?‘”/đ?‘ Ă— (49.0đ?‘˜đ??˝/đ?‘˜đ?‘” − 38.0đ?‘˜đ??˝/đ?‘˜đ?‘”) = 530.8đ?‘˜đ?‘Š đ?‘„đ?‘ƒđ?‘™đ?‘Žđ?‘›đ?‘Ą = đ?‘„đ??śđ?‘œđ?‘œđ?‘™đ?‘–đ?‘›đ?‘” Ă— đ?‘ƒđ?‘†đ?‘…
Factor
Reason
Comfort
The ability of the ACS to meet the variable requirements of the occupants is paramount to ensure that the workforce function effectively.
Financial
If LOB intends to retain and operate the building it would be advisable to install a more efficient ACS, as the reduced maintenance and energy costs will make the greater capital investment worthwhile.
Control
Since the cooling demand of the building varies greatly throughout the day, the ACS must be able to operate under a variable schedule. This prevents the ACS being active when it is not necessary, minimising energy use and environmental impact.
Noise Production
Noise production should adhere to an acceptable volume defined by occupants
Environmental
CO2 production and energy consumption should be minimised by selecting an efficient ACS.
= 530.8đ?‘˜đ?‘Š Ă— 1.2 = 637.0đ?‘˜đ?‘Š
AIR CONDITIONING SYSTEM (ACS)
28
Table 6-4: VAV system components
SYSTEM SELECTION Component
Variable Air Volume (VAV) systems are the most widely employed ACS in
The chiller provides a supply of chilled water to the AHU’s cooling coils
Air Handling Unit (AHU)
The AHU is the unit where air is treated. It contains the primary heating and cooling coils (powered by the boiler and chiller, controlling temperature), a steam humidifier (to control moisture content) and a large fan to circulate air though the duct network. It also contains a mixing box, which mixes fresh air with recirculated air.
VAV Terminal Units
VAV terminal units are located at each zone, where they can limit the flow rate of air passing into a specific zone (capped at 60% reduction). They also contain a fan to assist with local recirculation, and a heating coil (a legacy component from a time when energy costs were cheaper).
Room based Diffusers
The diffusers are mounted on the perimeter of occupied zones to distribute treated air to the spaces. They come in a variety of shapes, each working in a different manner, many by inducing the coanda effect.
Filters
Filters are placed in the network to remove particle based pollutants such as smoke or dust. If they were to build up it could cause decreased efficiency or health issues. An
Fans
Fans are used to move air through the duct network by increasing pressure at key points. All fans would need to be sized carefully to ensure adequate pressures to circulate air.
Figure 6-3: Fan Assisted VAV system schematic
29
Description
Chiller
modern office buildings. A centralised VAV system is specified for this building, with fan assisted terminals incorporated into the system.
Image
Tender Submission | K13IDM
Table 6-5: Advantages and Disadvantages of a VAV system Advantages
Disadvantages
 Good temperature control is achieved by thermoregulatory devices in VAV terminal units
 The complex system contains numerous components, and requires substantial maintenance.
 Uneven heating or cooling requirements can be met by varying air flow rates at each zone’s VAV terminal unit. Perimeter zones will generally have a greater cooling load than core zones. (e.g. đ?‘„đ?‘œđ?‘“đ?‘“đ?‘–đ?‘?đ?‘’ > đ?‘„đ?‘?đ?‘–đ?‘&#x;đ?‘?đ?‘˘đ?‘™đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› )
 A large plant room must be available to house the large boilers, chiller and AHU. Sufficient void space must also be available within the ceilings of the building to accommodate the large ducts that circulate treated air.
 Very flexible system is able to accommodate any future changes in AC requirement
 Requires careful planning and design of system as well as quality commissioning to ensure it functions correctly
 Fan assisted VAV units allow for zone by zone control of air flow rates, with up to 60% throttling of the system volume flow rate minimising energy wasting.  Recirculation can be employed easily within the terminal units, improving the efficiency of the ACS.
CONTROL The ACS should be controlled via a schedule that is refined with feedback from post-occupancy evaluation.
control should also be employed, operated by occupants for real time comfort adjustments. This should be through either real or perceived control (e.g. thermostats and fan controls; or false switches).
 Excess noise could occur if the fan assisted VAV terminal units are not acoustically insulated from occupied spaces.  Implementation of fan-assisted terminal units will increase capital and maintenance costs.
 Fan assistance ensures proper mixing, preventing air dumping.  Fresh air is supplied in the system, so no additional ventilation system is required.
AIR CONDITIONING SYSTEM (ACS)
Intuitive devices with partial local
30
6.3
ANNUAL RUNNING COSTS
Table 6-6: Three approaches to estimate ACS cooling load Estimation 1
Estimation 2
Estimation 3
Using general operational costs from CIBSE Guide F Table 7.5
Using general energy demand costs from CIBSE Guide B Table 2.2
Centralised VAV system assumption:
Type 3 (standard air-conditioned office) cooling load:
Using method to calculate the annual energy consumption based on peak cooling demand, as described by Chadderton.

Building occupied floor area: 9717đ?‘š2

Building occupied floor area: 9717đ?‘š2

CO2 emission: 40đ?‘˜đ?‘”/đ?‘š2 đ?‘?. đ?‘Ž

Energy Consumption: 31đ?‘˜đ?‘Šâ„Ž/đ?‘š2 đ?‘?. đ?‘Ž

ÂŁ2.40/đ?‘š2 đ?‘?. đ?‘Ž
Running Cost:
đ??¸đ?‘›đ?‘’đ?‘&#x;đ?‘”đ?‘Ś đ?‘‘đ?‘’đ?‘šđ?‘Žđ?‘›đ?‘‘ = đ??¸đ?‘›đ?‘’đ?‘&#x;đ?‘”đ?‘Ś đ?‘˘đ?‘ đ?‘’ đ?‘?đ?‘’đ?‘&#x; đ?‘š2 Ă— đ?‘“đ?‘™đ?‘œđ?‘œđ?‘&#x; đ?‘Žđ?‘&#x;đ?‘’đ?‘Ž đ?‘†đ?‘Śđ?‘ đ?‘Ąđ?‘’đ?‘š đ?‘ƒđ?‘&#x;đ?‘–đ?‘?đ?‘’ = đ??śđ?‘œđ?‘ đ?‘Ą đ?‘?đ?‘’đ?‘&#x; đ?‘š2 Ă— đ?‘“đ?‘™đ?‘œđ?‘œđ?‘&#x; đ?‘Žđ?‘&#x;đ?‘’đ?‘Ž đ??śđ?‘‚2 đ?‘’đ?‘šđ?‘–đ?‘ đ?‘ đ?‘–đ?‘œđ?‘›đ?‘ đ?‘’ = đ??¸đ?‘šđ?‘–đ?‘ đ?‘ đ?‘–đ?‘œđ?‘› đ?‘?đ?‘’đ?‘&#x; đ?‘š2 Ă— đ?‘“đ?‘™đ?‘œđ?‘œđ?‘&#x; đ?‘Žđ?‘&#x;đ?‘’đ?‘Ž
Find the peak temperature of mixed (đ?&#x2018;&#x2021;đ?&#x2018;&#x20AC;,đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ ) air prior to cooling (based on volume flow rates of outdoor air (đ?&#x2018;&#x2030;đ?&#x2018;&#x153; ), recirculated air (đ?&#x2018;&#x2030;đ?&#x2018;&#x; ) and total air (đ?&#x2018;&#x2030;đ?&#x2018;Ą ) and the design outdoor temp (đ?&#x2018;&#x2021;đ?&#x2018;&#x201A; ) and recirculation Temperature (đ?&#x2018;&#x2021;đ?&#x2018;&#x; ). đ?&#x2018;&#x2030;đ?&#x2018;&#x153; đ?&#x2018;&#x2021;đ?&#x2018;&#x153; + đ?&#x2018;&#x2030;đ?&#x2018;&#x; đ?&#x2018;&#x2021;đ?&#x2018;&#x; 7.22 Ă&#x2014; 25.8 + 32.6 Ă&#x2014; 23 đ?&#x2018;&#x2021;đ?&#x2018;&#x20AC;,đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ = = = 23.5°đ??ś đ?&#x2018;&#x2030;đ?&#x2018;Ą 39.8 Finding the average cooling required (Î&#x201D;đ?&#x2018;&#x2021;đ?&#x2018;&#x17D;đ?&#x2018;Łđ?&#x2018;&#x2019; ) required. Î&#x201D;đ?&#x2018;&#x2021;đ?&#x2018;&#x20AC;â&#x2C6;&#x2019;đ?&#x2018;&#x2020;,đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ = đ?&#x2018;&#x2021;đ?&#x2018;&#x20AC;,đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ â&#x2C6;&#x2019; đ?&#x2018;&#x2021;đ?&#x2018; = 23.5 â&#x2C6;&#x2019; 14.0 = 9.5°đ??ś Assuming sinusoidal fluctuation in outdoor air temperature finds the mean mixed air temperature đ?&#x2018;&#x2021;đ?&#x2018;&#x20AC;,đ?&#x2018;&#x17D;đ?&#x2018;Łđ?&#x2018;&#x2019; by multiplying đ?&#x2018;&#x2021;đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ by 70.7%. The average cooling power (đ?&#x2018;&#x201E;đ?&#x2018;?đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x2122;,đ?&#x2018;&#x17D;đ?&#x2018;Łđ?&#x2018;&#x2019; ) of the ACS can then be determined with the total volume flow rate of air, air density (đ?&#x153;&#x152;) and specific heat capacity of air (đ?&#x2018;?). đ?&#x2018;&#x201E;đ?&#x2018;?đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x2122;,đ?&#x2018;&#x17D;đ?&#x2018;Łđ?&#x2018;&#x2019; = đ?&#x2018;&#x2030;đ?&#x2018;&#x2021; Ă&#x2014; đ?&#x153;&#x152; Ă&#x2014; đ?&#x2018;? Ă&#x2014; (Î&#x201D;đ?&#x2018;&#x2021;đ?&#x2018;&#x17D;đ?&#x2018;Łđ?&#x2018;&#x2019; Ă&#x2014; 70.7%) = 39.8 Ă&#x2014; 1.21 Ă&#x2014; 1020 Ă&#x2014; (9.5°đ??ś Ă&#x2014; 70.7%) = 330.9đ?&#x2018;&#x2DC;đ?&#x2018;&#x160; Hours of operation (đ?&#x2018;Ąđ?&#x2018;?đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x2122; ) are determined as any time when đ?&#x2018;&#x2021;đ?&#x2018;&#x;đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x161; < đ?&#x2018;&#x2021;đ?&#x2018;&#x2019;đ?&#x2018;Ľđ?&#x2018;Ąđ?&#x2018;&#x2019;đ?&#x2018;&#x;đ?&#x2018;&#x203A;đ?&#x2018;&#x17D;đ?&#x2018;&#x2122; . The number is determined based on the proportion of hours during summer (CIBSE Guide A Table 2.13) that exceeds đ?&#x2018;&#x2021;đ?&#x2018;&#x;đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x161; , multiplied by hours in a year.
Data provided is for 1992 cost so by applying inflation, according to the bank of England, the corrected running cost is ÂŁ4.43/đ?&#x2018;&#x161;2 đ?&#x2018;?. đ?&#x2018;&#x17D;
â&#x20AC; Energy load is converted to monetary value/ CO2 emission load using standard conversion factors as provided by the energy savings trust, 1kWh = ÂŁ0.1319 and 0.519kgCO2, dated 2015
đ?&#x2018;Ąđ?&#x2018;?đ?&#x2018;&#x153;đ?&#x2018;&#x153;đ?&#x2018;&#x2122; = 11.49% Ă&#x2014; 8760â&#x201E;&#x17D;đ?&#x2018;&#x;/đ?&#x2018;Śđ?&#x2018;&#x; = 1007â&#x201E;&#x17D;đ?&#x2018;&#x;đ?&#x2018; The annual energy can then be calculated as đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x; Ă&#x2014; đ?&#x2018;&#x2021;đ?&#x2018;&#x2013;đ?&#x2018;&#x161;đ?&#x2018;&#x2019; Ă&#x2014; đ??śđ?&#x2018;&#x201A;đ?&#x2018;&#x192;. (Chadderton recommends 2.50 in cases where value is not specified)
Energy
n/a
301,227 kWh p.a
133,215 kWh p.a
Price
ÂŁ43,045 p.a
ÂŁ42,322 p.a â&#x20AC;
ÂŁ17,571 p.a â&#x20AC;
CO2
388.7 tonnes p.a
147.6 tonnes p.a â&#x20AC;
69.1 tonnes p.a â&#x20AC;
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The three approaches predict significantly different cost and CO2 emissions. However the costs are of a comparable magnitude, implying an annual cost of ÂŁ20-40,000 for cooling. The CO2 emissions are far less coherent, with the older approach (1) predicting carbon emissions over 500% higher than the modern approach (3).
This is potentially due to the increase in renewable electricity
production since 1992, reducing the amount of CO2 produced per kWh. It would be expected that Estimation 3 would be most accurate, as it is derived from the actual buildingâ&#x20AC;&#x2122;s performance, as opposed to generic area-weighted assumptions.
The only way to evaluate expenses
accurately would be by examining the building once it is in service. (477)
AIR CONDITIONING SYSTEM (ACS)
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7
VENTILATION
7.1
DESIGN CRITERIA
Table 7-1: Ventilation Requirements Parameter
To ensure that the ventilation system will adhere to Approved Document
Offices
Lobby
Required Fresh Airflow Rate per Floor (m /s)
0.79
0.11
Mixing Ratio [dimensionless]
0.82
0.82
Total Airflow Rate Per Floor (m /s)
3.57
0.50
Number of Diffusers Per Floor [dimensionless]
8
2
Airflow per Diffuser (m /s)
0.45
0.25
Throw length (m)
7
4.5
Sound Level dbA *
30
24
3
F [9] it must:
3
Supply adequate fresh air
3
Supply the total air required for heating and cooling to occupied zones
*from gilberts curved blade grills documentation [8]. Must not exceed 30 dbA in office
Ensure mixing of air
buildings. Can be reduced using more adjustable blades
Not produce excessive noise
7.2
Provide extraction in sanitary accommodations
The primary vertical ductwork can be housed in the existing services
DUCT CONFIGURATION
shafts. By dividing the system into two symmetrical networks pressure losses are reduced. The ducts to the supply diffusers will run within the ceiling void, see Figure 7-1 and 7-2
VENTILATION
34
Figure 7-2: Supply Duct layout in Section
SANITARY AND NON-SANITARY ACCOMMODATION The ventilation in the sanitary accommodations uses local extraction. The zone is depressurised to avoid any mixing with air in non-sanitary zones Approved document F [9] specifies the requirement for this is an intermittent air extract of 6 L/s per WC or Urinal. The total extract for each zone is shown Table 7-2.The supply air is drawn from other ventilated zones.
Figure 7-1: Duct Layout in Plan
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Table 7-2: Total extract for each sanitary zone
Sanitary Accommodation
Configuration
Total Extract for Zone (L/s) 18
Ground Floor Male
1 WC 2 Urinals
Ground Floor Female
3 WCs
18
Typical Floor Male
4 WCs 3 Urinals
42
Typical Floor Female
5 WCs
30
SUPPLY INDEX RUN The supply index run shown in Figure 7-3 runs from the plant room to the furthest supply terminal on the first floor (not the ground floor as terminals are only located in the central core, close to the main riser).
Figure 7-3: Supply Index Run
VENTILATION
36
Table 7-3: Pressure Drop over Index Run
SUPPLY INDEX RUN PRESSURE DROP The total pressure loss over the index run is a combination of the pressure loss along the pipes due to friction and the pressure loss over components. The pressure loss along pipes is given by:
Parameter
Value
Unit
Pressure loss along Pipes (Friction)*
40.21
Pa
Pressure loss over components*
103.58
Pa
Total pressure drop over index run
143.79
Pa
Found using method CIBSE Guide B [3] and values from CIBSE Guide C [10] for breakdown please see appendix C
1
Î&#x201D;p = Îť â&#x2C6;&#x2019; 2 Ď đ?&#x2018;? 2
[7-1]
7.3
FANS
The energy consumption of the system fans is calculated using the
Where Îť is the friction factor found using chart 4.2 in CIBSE Guide C, Ď is the density of air (1.2 kg/m3) and c is the specific heat capacity of air (1.0
method given in CIBSE Guide B chapter 3 [3]:
kJ/kg.K). [10]
đ??´đ?&#x2018;&#x2013;đ?&#x2018;&#x; đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x; = đ?&#x2018;&#x201E;đ?&#x2018;&#x2021; â&#x2C6;&#x2020;đ?&#x2018;? 1
â&#x2C6;&#x2020;đ?&#x2018;? = Îś 2 Ď đ?&#x2018;? 2
[7-3]
đ??´đ?&#x2018;&#x2013;đ?&#x2018;&#x; đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x; = 16.3 Ă&#x2014; 143.79 = 2343đ?&#x2018;&#x160;
[7-2]
The electrical power required based on the fanâ&#x20AC;&#x2122;s efficiency (90% [6])
Where Îś is the component loss factor obtained from tables in CIBSE Guide C Chapter 4.
đ??¸đ?&#x2018;&#x2122;đ?&#x2018;&#x2019;đ?&#x2018;?đ?&#x2018;Ąđ?&#x2018;&#x;đ?&#x2018;&#x2013;đ?&#x2018;? đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x; =
đ??´đ?&#x2018;&#x2013;đ?&#x2018;&#x; đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x; đ?&#x153;&#x2021;
[7-4]
The results of these calculations are found in Table 7-3 and detailed in depth in Appendix C.
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There are four fans in the building; two supply and two extract. The total
Each fanâ&#x20AC;&#x2122;s energy consumption is given by: đ??¸đ?&#x2018;&#x203A;đ?&#x2018;&#x2019;đ?&#x2018;&#x;đ?&#x2018;&#x201D;đ?&#x2018;Ś đ??śđ?&#x2018;&#x153;đ?&#x2018;&#x203A;đ?&#x2018; đ?&#x2018;˘đ?&#x2018;&#x161;đ?&#x2018;?đ?&#x2018;Ąđ?&#x2018;&#x2013;đ?&#x2018;&#x153;đ?&#x2018;&#x203A; = đ?&#x2018;Ąđ?&#x2018;&#x153;đ?&#x2018;? đ??¸đ?&#x2018;&#x2122;đ?&#x2018;&#x2019;đ?&#x2018;?đ?&#x2018;Ąđ?&#x2018;&#x;đ?&#x2018;&#x2013;đ?&#x2018;? đ?&#x2018;&#x192;đ?&#x2018;&#x153;đ?&#x2018;¤đ?&#x2018;&#x2019;đ?&#x2018;&#x;
energy consumption and a summary of data in this section are given in
[7-5]
Table 7-5 Table 7-4: Equation Parameters Table 7-5: Fan and energy characteristics
Term
Definition
top
operational time
Parameter
Value
Unit
(17 hours a day during warm up period and occupation, week days)
Total Pressure Drop
143.79
Pa
Air power
2,343
W
Fan Efficiency
90%
[percentage]
Electric Power
2,604
W
Operational Time
4080
hr
Energy Consumption Fan
10,623
kWhr
Number of Fans
4
[dimensionless]
Total Electric Power
10,414.56
W
Total Energy Consumption
42,491
kWhr
QT
total flow rate (16.30 m/s)
Î&#x201D;p
total pressure loss over the index circuit
System Calculations Electric Power = 2343/0.9 = 2604W Top= 17hours*240days = 4080hrs Therefore Energy consumption = 4080*2.604 = 42491 kWhrs
VENTILATION
38
7.4
SUPPLY DIFFUSER CHOICE
The supply diffusers are situated in the ceiling due to the duct placement and to take advantage of the coanda effect They are sized using equation 7-6. đ??śđ?&#x2018;&#x201E;
đ?&#x2018;&#x2C6;đ?&#x2018;&#x161;đ?&#x2018;&#x17D;đ?&#x2018;Ľ = đ?&#x2018;Ľđ??´0.5 andđ??´đ?&#x2018;&#x2019; = 0.6đ??´đ?&#x2018;&#x153;
[7-6]
đ?&#x2018;&#x2019;
Table 7-6: Supply Diffuser Sizing Term
Definition
Offices
Lobby
Umax
Umax (m/s)
0.25
0.25
C
Hueretic Constant
5.5
5.5
x
Throw (m)
7
4.5
0.45
0.25
1.96
1.47
3.27
2.46
Q Ae Ao
3
Flow Rate (m /s) 2
Effective Area Opening (m ) 2
Area Diffuser (m )
Example calculation (office diffuser) Ae = ((5.5*0.45)/(7*0.25))2 Ao = 1.96/0.6
= 1.96m2
= 3.27m2
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VENTILATION
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8
SENSITIVITY ANALYSIS
Reductions in the buildingâ&#x20AC;&#x2122;s energy consumption and carbon emissions
INSTALLING TRIPLE GLAZING
can be achieved by making a series of changes to the buildingâ&#x20AC;&#x2122;s geometry
The heat lost though the buildingâ&#x20AC;&#x2122;s glazing can be
and thermal envelope.
reduced by installing triple glazing.
8.1
The triple
glazing will slightly reduce the solar radiant gains as
POTENTIAL CHANGES
well, reducing the cooling load during summer. IMPROVING FABRIC THERMAL PERFORMANCE Table 8-2: Comparing performance of double glazing vs triple glazing
Reduced conductive heat transfer though the
Window Type
thermal envelope can be obtained by reducing
2
U-Value (W/m K)
G-Value
Response Factor
Double Glazing (reflective coating)
2.2
0.41
0.50
Triple Glazing (reflective coating)
0.9
0.35
0.43
fabric U-values. To quantify the potential savings, the U-values are reduced to 0.15đ?&#x2018;&#x160;/đ?&#x2018;&#x161;2 đ??ž, in line with ACEB Gold Standard building TOTAL SOLAR SHADING performance [11]. The peak cooling load can be reduced by applying Table 8-1: U-value comparison of Part L requirement and ACEB Gold Standard Fabric Element
2
total solar shading to the building. The solar load 2
Part L Minimum (W/m K)
ACEB Gold Standard (W/m K)
Wall
0.35
0.15
Floor
0.25
0.15
Roof
0.25
0.15
SENSITIVITY ANALYSIS
on each façade is redefined as north facing.
42
INCREASING THERMAL MASS
8.2
COMPARISON OF CHANGES Table 8-4: Comparison of changes
The effect of environmental changes can be offset Alteration
by increasing the thermal mass of the building; changing it to a slow response building. Table 8-3: Effect of increasing thermal mass Building Element
Lag, φ (hrs)
Decrement Factor, f
Response Factor
Fast
Slow
Fast
Slow
Fast
Slow
Wall
5
9
0.58
0.21
-
-
Roof
2
10
0.93
0.15
-
-
Floor
2
9
0.91
0.15
-
-
Vehicle Access Doors
1
1
1
1
-
-
Glazing
-
Affects Heating Load?
Affects Cooling Load?
Affects Ventilation Load
Energy Demand (kWh)
Saving (%)
CO2 Emissions (Tonnes)
Saving (%)
Original
n/a
n/a
n/a
1164210
-
305
-
Triple Glazing
✓
✓
✓
960134
18.0%
249
18.0%
Fabric Uvalues
✓
✓
✓
1130812
3.0%
297
3.0%
Total Solar Shading
✓
✓
1137502
2.0%
291
5.0%
Increase Thermal Mass
✓
✓
1150135
1.0%
301
1.0%
925,295
21.0%
241
21.0%
Net effect
Note: Each of the changes only alters the sensible loads, not the latent loads, resulting in a -
-
-
0.50
different room ratio. This slightly alters the psychometric process for the air conditioning
0.43
cycle. However, the changes in enthalpies are so small that the margin of error incurred becomes negligible (<1%) when considering the inaccuracies in the original calculations.
The heating load is far greater than the cooling load. Changes that affect only the cooling load of the building will therefore have a lesser impact on the total energy demand, but comparatively high financial savings due to the relative expense of electricity compared to gas.
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8.3
RECCOMMENDATIONS Table 8-5: Recommendations
Alteration
Energy Saving (%)
CO2 Saving (%)
18.00%
18.00%
Triple Glazing
made. However, it is only cost effective to employ most of the changes if By installing triple glazing, upwards of £8000 p.a could be saved. The expense of the upgrade is around £500,000 making the payback around 50 years [4]. Financially, it may not be in LOB’s best interests if they want a quick return on their investment. It would however be environmentally beneficial as significant amounts of energy and CO2 can be saved.
Fabric U-values
3.00%
3.00%
A saving of around £1500 p.a. could be attained by adding insulation to the walls roof and floors. The payback time of such an upgrade would be in the region of 50 years [11]. Other elements of the building’s fabric could also be improved, seeing comparable benefits.
Total Solar Shading
2.00%
5.00%
Up to £2000 p.a. could be saved by adding solar shading. Shading should definitely be implemented, either by adding louvres or increasing window recesses, as there are minimal capital costs for such modifications (an effective shading device should overhang the windows by 2.8m).
Increase Thermal Mass
1.00%
1.00%
The response time of the building should be increased to save energy and money at no additional capital cost. Free night cooling could also be employed to further increase energy savings.
SENSITIVITY ANALYSIS
From an environmental standpoint all the above changes should be
Feasibility
LOB plan to operate the building for 50 years to see payback on their additional investment.
Figure 8-1: Comparison of changes
(226)
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9
FIRE PROTECTION Table 9-2: Number of routes required, taken from Approved Document B, [12]
The building is assessed for fire protection, to ensure that it conforms to Approved Document B of the UK Building Regulations. It must be protected from the effects of heat, using fire resistant construction, and
Floor
Number of People
Office Entrance
79 11
Required number of exit routes 2 1
protect occupants from smoke, using compartmentalisation. Figures 9-1 to 9-4 show the available exits and 18m travel routes from the 9.1
HORIZONTAL ESCAPE office and entrance floors respectively. Not all areas of the floor are
Escape routes and travel distances are assed. Maximum travel distances within 18m of a fire exit; so additional doors will need to be fitted to from any point on a floor to that storeyâ&#x20AC;&#x2122;s exit can be seen in Table 9-1. meet the minimum guidelines. Table 9-1 Maximum travel distances, taken from Approved Document B, [12]
Room Office (Floors 1-10) Entrance (Ground floor)
Primary Direction (m) 18 18
Inner rooms such as the sanitary accommodation, must also adhere to
Secondary Direction (m) 45 45
the guidelines, and open directly onto the access floor.
For each upper floor there are two means of horizontal escape, and three for the ground floor. Table 9-2 shows that the current conditions meet required standards.
FIRE PROTECTION
46
Figure 9-1: Typical office floor, not meeting maximum travel distances
Figure 9-3: Entrance floor, not meeting maximum travel distances
Figure 9-2: Typical office floor, meeting maximum travel distances
Figure 9-4: Entrance floor, not meeting maximum travel distances
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9.2
VERTICAL ESCAPE
9.3
COMPARTMENTALISATION OF SPACES
Stair carrying capacities and widths are assessed. Table 9-3 shows the
To control the spread of fire the internal spaces are compartmentalised,
minimum escape widths required. A fire may prevent one of the exits
separated by fire resistant walls and floors. The number of compartments
from being used so all exit widths must adhere to these guidelines.
depends on:
Table 9-3: Minimum exit widths, Approved document B, [12]
Floor Office Entrance
Number of People 79 11
Exit Width (mm) 850 750
ď&#x201A;§
Building use
ď&#x201A;§
Building height
ď&#x201A;§
Availability of a sprinkler system
Since the office is open plan, all staircases must be capable of
Table 9-4 shows that the building requires all storeys to be separated by
simultaneous evacuation.
compartment floors, but compartment walls will not be necessary. Figure 9-5 shows the configuration.
Example Calculation: Width of Stairs, using table 7 Approved Document B Table 9-4: Compartment regulations, Approved document B, [12]
79 people x 9 upper floors = 711 people 711 people = 1400mm width of stairs required Guidelines LOB
FIRE PROTECTION
48
Maximum Total Height without compartment floors (m)
Maximum Floor Area without compartment walls (đ?&#x2019;&#x17D;đ?&#x;? )
30 37.5
2000 985
9.4
PROTECTION OF VENTILATION OPENINGS
In some cases ventilation openings breach the dividers that separate adjacent fire compartments. They need to be protected so the fire barrier remains intact. They can be protected by:
Fire dampers Fire-resisting enclosures Fire resisting ductwork
Fire dampers should be installed around the openings with sufficient tolerance to allow access for maintenance and room for expansion in the heat of a fire. Pipes below 160mm internal diameter, that penetrate through the fire-separating compartments will require sleeving of noncombustible pipe, see Figure 9-6.
Figure 9-5: Compartment floor configuration, meeting approved document Bs guidelines.
Figure 9-6: Pipe sleeving, taken from Approved Document B, [12]
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9.5
LOCATION OF FIRE-FIGHTING SERVCES
Hydrants, hoses, risers and sprinklers must be suitably placed to assist fire fighters in time of need. Fire mains with valves must be installed within the building so that fire fighters can connect hoses for water rapidly. The fire fighting shafts and necessary escape stairs must be equipped with fire mains. The mains can be â&#x20AC;&#x2DC;dryâ&#x20AC;&#x2122; type due to the building being less than Figure 9-7: ground floor sprinkler system
50m tall. A sprinkler system must be installed throughout the building since it is taller than 30m. These systems ensure occupant safety and reduce fire damage. Table 9-5 sets out the standards for a sprinkler system, and Figures 9-7 and 9-8 shows an appropriate configuration for the building. Table 9-5: Maximum sprinkler distances, BSEN pg 77 , [13], [14] Hazard Class Ordinary
Space required below roof and ceiling sprinklers (m) 0.5
Maximum area per sprinkler (đ?&#x2019;&#x17D;đ?&#x;? ) 12
Maximum distances between sprinklers (m)
Figure 9-8: Office floor sprinkler system
The main sprinkler riser should be placed centrally with primary pipelines
4
running horizontally across each floor. (484)
FIRE PROTECTION
50
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Tender Submission | K13IDM
10
VERTICAL TRANSPORT
The building is served by four lift shafts, two on either side of the lobby. The dimensions of each shaft are shown in Table 10-1. The buildingâ&#x20AC;&#x2122;s lift to floor ratio of 1:2.5 places it in the excellent quality of service category according to British standards lifts and lift services section 6.4.5 [16]. Table 10-1: Lift Shaft Dimensions
Parameter
Value
Unit
Width
0.95
m
Depth
4.5
m
Height
37.8
m
Area
4.3
m
2
161.6
m
3
Volume
Figure 10-1: Exploded View of Building Showing Lifts
VERTICAL TRANSPORT
52
10.1
Table 10-2: Breakdown of Car Capacity
SYSTEM MECHANICS
PASSENGERS PER CAR The total area of a lift shaft is 4.1m2. The corresponding car floor area is 2
2.4m to allow space for the counterweight and runners between car and
2
Component
Area (m )
Total Lift Shaft Area
4.30
Counterweight including movement tolerance
0.68
Space for Runners
0.67
Car Area
2.41
Capacity
12 People
shaft walls, as shown in Figure 10-2. The capacity of each car is calculated assuming each passenger requires
DOOR TYPE
0.2m2 of floor space, see Table 10-2.
Current plans suggest a side opening. As stated in section 5.2.4 of British standards [16] a centre opening would provide improved operation (door opening/closing) times and aesthetics
Figure 10-3: Comparison of Side Opening and Two-Speed Centre Opening Doors Figure 10-2: Plan of Lift Showing Dimensions around Car as given in CIBSE Guide D 0
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ROPING MECHANISM
DESIGN CONSIDERATIONS FOR THE DISABLED
The roping mechanism is housed at the top of the building to allow the
Lift is essential in this building for disabled access as it over one story. The
load to act directly downwards. Since the lifts only have a capacity of 12
distance from a lift to the furthest point away from a lift is about 30m this
a single wrap pulley system can be used. This is the most economical and
is well under the maximum walking distance limit of 45m [16] and so
efficient system.
allows for any deviation from the direct route due to, for example, furniture layout.
Figure 10-4: Single Wrap Pulley System CAR SPEED
The recommended car speed for a building 37m tall is 2.5 m/s, as specified in table 6 of British standards lifts and lift services document [16].
VERTICAL TRANSPORT
54
10.2
Table 10-3: System specification
FIREFIGHTING LIFTS Starting Values
Fire-fighting lifts are a requirement for the transportation of the disabled in the event of a fire. These lifts must be situated within the fire-fighting shaft enclosed by a fire resistant structure that also contains stairs. All buildings with over 900m^2 must have two fire-fighting lifts installed. However if a sprinkler system is in place, one lift is sufficient, providing the entire floor area is within 60m of the lift shaft. [16]. 10.3
No. of Stories
10
People Above Ground
722
Total Occupancy
Floor Height (m)
3.6 (typical)
4.2 (ground)
Total Lift Flight L (m)
33
4.2+8*3.6
Door Width w (m)
1
Door Speed vd (m/s)
0.4
Lift Capacity n
12
Lift Speed v (m/s)
2.5
Number of Cars N
4
Aim (people in 5 minutes)
87
typical CIBSE guide d
12% population in five minutes (CIbSE Guide D)
Table 10-4: Lift Calculations for Quality of Service
QUALITY OF SERVICE ASSESSMENT
The round trip calculations are shown in Table 10-4. Table 10-3 collates relevant values already established. 116 people can be carried by the system in five minutes, well above the recommended 87. The maximum waiting time of 31.1s puts the system in the excellent category for quality of service. [16]
55
Tender Submission | K13IDM
Calculations Probable Number of Stops S1
Calculated Value
đ?&#x2018;&#x2020;1 = đ?&#x2018;&#x2020; â&#x2C6;&#x2019; đ?&#x2018;&#x2020; (
đ?&#x2018;&#x2020;â&#x2C6;&#x2019;1 đ?&#x2018;&#x203A; đ?&#x2018;&#x2020;
)
where S = Maximum number of stops = 9
n = lift capacity =12
6.8
8 12
= 9â&#x2C6;&#x2019;9( ) 9
Upward journey time Tu
đ?&#x2018;&#x2021;đ?&#x2018;˘ = đ?&#x2018;&#x2020;1 (
đ??ż
đ?&#x2018;&#x2020;1 đ?&#x2018;Ł 33
= 6.8 ( Downward journey time Td
+ 2đ?&#x2018;Ł)
6.8â&#x2C6;&#x2014;2.5
where L = Total lift flight = 33m v = Lift velocity = 2.5 m/s
43.0s
+ 2 â&#x2C6;&#x2014; 2.5)
đ??ż
đ?&#x2018;&#x2021;đ?&#x2018;&#x2018; = ( + 2đ?&#x2018;Ł) đ?&#x2018;Ł
at peak demand car is assumed to run non=stop from top to bottom
18.2s
where W = door width = 1m Vd = door velocity = 0.4 m/s
39.1s
2 seconds per passenger is assumed
24.0s
33 =( + 2 â&#x2C6;&#x2014; 2.5) 2.5 Door opening time To
đ?&#x2018;&#x2021;đ?&#x2018;&#x153; = 2(đ?&#x2018;&#x2020;1 + 1)
đ?&#x2018;&#x160; đ?&#x2018;&#x2030;đ?&#x2018;&#x2018; 1
= 2(6.8 + 1)
0.4
Passenger transfer time Tt
đ?&#x2018;&#x2021;đ?&#x2018;Ą = 2đ?&#x2018;&#x203A; = 2 â&#x2C6;&#x2014; 12
Round trip time RTT
đ?&#x2018;&#x2026;đ?&#x2018;&#x2021;đ?&#x2018;&#x2021; = đ?&#x2018;&#x2021;đ?&#x2018;˘ + đ?&#x2018;&#x2021;đ?&#x2018;&#x2018; + đ?&#x2018;&#x2021;đ?&#x2018;&#x153; + đ?&#x2018;&#x2021;đ?&#x2018;Ą = 43 + 18.2 + 39.1 + 24
Interval for group
đ??źđ?&#x2018;&#x203A;đ?&#x2018;Ąđ?&#x2018;&#x2019;đ?&#x2018;&#x;đ?&#x2018;Łđ?&#x2018;&#x17D;đ?&#x2018;&#x2122; =
đ?&#x2018;&#x2026;đ?&#x2018;&#x2021;đ?&#x2018;&#x2021; đ?&#x2018;
124.3s
where N = number of lift cars = 4
124.3 4 5 â&#x2C6;&#x2014; 60 â&#x2C6;&#x2014; đ?&#x2018; đ??˝đ?&#x2018;&#x153;đ?&#x2018;˘đ?&#x2018;&#x;đ?&#x2018;&#x203A;đ?&#x2018;&#x2013;đ?&#x2018;&#x2019;đ?&#x2018; = đ?&#x2018;&#x2026;đ?&#x2018;&#x2021;đ?&#x2018;&#x2021; 5 â&#x2C6;&#x2014; 60 â&#x2C6;&#x2014; 4 = 124.3 đ?&#x2018;ľđ?&#x2019;?. đ?&#x2019;?đ?&#x2019;&#x2021; đ?&#x2018;ˇđ?&#x2019;&#x2020;đ?&#x2019;?đ?&#x2019;&#x2018;đ?&#x2019;?đ?&#x2019;&#x2020; = đ?&#x2018;ąđ?&#x2019;?đ?&#x2019;&#x2013;đ?&#x2019;&#x201C;đ?&#x2019;?đ?&#x2019;&#x160;đ?&#x2019;&#x2020;đ?&#x2019;&#x201D; Ă&#x2014; đ?&#x2019;? = đ?&#x;&#x2014;. đ?&#x;&#x2022; Ă&#x2014; đ?&#x;?đ?&#x;?
31.1s
=
Number of journeys in five minutes
Number of people carried in five minutes
9.7
116
(382)
VERTICAL TRANSPORT
56
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Tender Submission | K13IDM
11
CONCLUSIONS less financially viable as they will take 50 years to see a financial
The key findings from this investigation are: ď&#x201A;§
return.
The peak-heating load for the building is 482 kW, occurring ď&#x201A;§
between 06:00 and 07:00, December 4th. This requires a boiler
have less effect on energy and đ??śđ?&#x2018;&#x201A;2 savings, between 1 and 5%,
plant size of 578 kW capable of meeting peak requirements. ď&#x201A;§
however they are more financially feasible.
The peak-cooling load for the building is 443 kW, occurring between 14:00 and 15:00, August 4th.
ď&#x201A;§
This requires an air
ď&#x201A;§
meeting maximum horizontal travel distances. Additional fire
The series of potential improvements included altering: o
Fabric properties
o
Glazing type
o
Shading
o
Thermal mass
The building does not conform to Approved Document B of the UK Building Regulations with regards to fire protection, when
conditioning system of 637 kW. ď&#x201A;§
In the short-term total solar shading and increased thermal mass
doors must be implemented to rectify this. ď&#x201A;§
It was seen that the current configuration of proposed vertical transport system more than capable of meeting the buildingâ&#x20AC;&#x2122;s requirements, putting the building into the â&#x20AC;&#x2DC;excellentâ&#x20AC;&#x2122; category according to British Standards for lifts and lift services.
The two changes that save the greatest amount of energy and đ??śđ?&#x2018;&#x201A;2 are installing triple glazing windows and upgrading the fabric in line with ACEB Gold Standard regulations. They are however
(230)
CONCLUSIONS
58
59
Tender Submission | K13IDM
CONCLUSIONS
60
12
BACK MATTER
12.1
REFERENCES
[9] HM Government. Approved Document F: Ventilation (Building Regulations). 2000
[1] CIBSE. Guide A: Environmental Design. 2006
[10] CIBSE. Guide C: Reference Data. 2007
[2] HM Government. Approved Document L2: Conservation of Fuel and Power in New Buildings Other than Dwellings (Building
[11] AECB. CarbonLite Program Guidance. 2009
Regulation). 2010 [12] HM Government. Approved Document B volume 2: Fire Safety [3] CIBSE. Guide B: Heating, ventilating, air conditioning and
– Buildings other than dwelling houses (Building Regulations).
refrigeration. 2005
2010
[4] BRE. The Government’s Standard Assessment Procedure for
[13] British Standard. BS EN
Energy Rating of Dwellings. 2012
12845:2004 +A2:2009: Fixed
firefighting systems – Automatic sprinkler systems – Design, installation and maintenance. 2004, 2009.
[5] R. Jones. Gilberts. Guest Lecture at the University of Nottingham. 2015
[14] British Automatic Fire Sprinkler Association (BAFSA). Using Sprinkler Systems in Buildings and Structures, Compliance with
[6] B. Jones. Air Conditioning Lecture notes. University of
Current Fire Safety Guidance. 2011
Nottingham. 2015
[15] CIBSE. Guide J: Weather, solar and illuminance data. 2002
[7] D. Oughton. Faber & Kell's Heating & Air-conditioning of Buildings. 2008
[16] BSI Standards Publishing. BS 5655-6 Lifts and Lift Services. 2011
[8] Gilberts. Series G curved blade Grilles. 2012
CIBSE. Guide D: Transportation in buildings. 2010
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BACK MATTER
II
12.2
APPENDIX A Table 12-1: Weather data used for Heating Season Calculations, taken from CIBSE Guide J, Table 5.36
Hour 1
January 29th 2.5
February 26th 2.3
March 29th
April 28th
May 29th
June 21st
July 4th
August 4th
October 4th
15.7
September 4th 11.6
4.8
7.1
9.8
13.9
14.8
9
November 4th 5.2
December 4th 1.3
2
2
2
4.3
6.4
9.2
13.1
14.2
15
11.1
8.6
5
1.1
3
1.9
1.9
4.1
6
8.7
12.4
13.6
14.4
10.4
8.2
4.5
0.7
4
1.4
1.5
3.5
5.6
8.3
12
13.2
13.9
9.9
7.8
4.3
0.2
5
1.2
1.4
3.2
5.3
8.1
12.2
13.3
13.4
9.6
7.5
3.9
0
6
0.9
1.2
3
5.7
9.2
13.3
14.3
14
9.6
7.4
3.7
-0.2
7
0.7
1.1
3.2
7.4
10.9
15
15.9
15.6
10.6
7.8
3.7
-0.4
8
0.7
1.4
4.6
9.4
12.7
16.8
17.7
17.4
12.7
9.2
3.9
-0.3
9
1.2
2.5
6.6
11.1
14.4
18.5
19.5
19.4
15.1
11.4
5.4
-0.1
10
2.3
3.8
8.2
12.8
16
20.1
21
21.2
17.2
13.4
7
1.2
11
3.7
5.2
9.7
14.3
17.4
21.5
22.5
22.6
18.6
14.8
8.4
2.7
12
4.7
6.3
11.1
15.2
18.4
22.7
23.4
23.9
19.6
15.9
9.5
4
13
5.5
7.1
12.1
16
19.3
23.6
24.2
24.8
20.4
16.4
9.9
4.9
14
5.9
7.7
12.6
16.4
19.8
24.4
24.8
25.4
21
16.6
10.2
5.4
15
5.8
7.7
12.7
16.4
20.1
24.5
25.3
25.8
21.2
16.8
10
5.1
16
5.3
7.2
12.6
16.1
20
24.4
25.4
25.7
21.1
15.9
9.1
4.1
17
4.3
6.1
12.1
15.5
19.6
24.2
25
25.2
20.5
14.9
7.9
3.3
18
3.7
5
10.9
14.6
18.8
23.5
24.4
24.3
19.4
13.6
7.3
2.7
19
3.3
4.4
9.7
13.2
17.4
22.5
23.3
23
18
12.8
6.7
2.2
20
3
3.8
8.6
11.8
15.7
20.9
21.7
21.3
16.6
11.9
6.3
1.8
21
2.7
3.3
7.7
10.8
14.3
19.3
20.1
20
15.4
11.1
5.9
1.6
22
2.2
3
6.8
9.7
13.1
17.9
18.9
18.9
14.4
10.5
5.7
1.4
23
1.8
2.7
5.8
9.1
12.1
16.8
17.5
18
13.5
9.8
5.4
1.1
24
1.8
2.5
5.6
8.3
11.4
15.7
16.7
17.1
12.9
9.5
5
0.7
Average
2.9
3.8
7.6
11.0
14.4
18.7
19.6
19.8
15.4
11.7
6.4
1.9
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Tender Submission | K13IDM
Table 12-2: Fabric gains/Losses (Wall, Roof, Glazing)
Hour
January
February
March
April
May
June
July
August
September
October
November
December
1
-415929
-420195
-366871
-339142
-281552
-194100
-174904
-155707
-243159
-277286
-358339
-441525
2
-426594
-426594
-377536
-354073
-294350
-211164
-187701
-170638
-253823
-285818
-362605
-445791
3
-428727
-428727
-381802
-362605
-305015
-226095
-200499
-183435
-268754
-294350
-373270
-454323
4
-439392
-437259
-394600
-371137
-313547
-234627
-209031
-194100
-279419
-302882
-377536
-464988
5
-443658
-439392
-400998
-377536
-317813
-230361
-206898
-204765
-285818
-309281
-386068
-469253
6
-450057
-443658
-405264
-369004
-294350
-206898
-185568
-191967
-285818
-311414
-390334
-473519
7
-454323
-445791
-400998
-332743
-258089
-170638
-151441
-157840
-264488
-302882
-390334
-477785
8
-454323
-439392
-371137
-290084
-219696
-132244
-113047
-119446
-219696
-273020
-386068
-475652
9
-443658
-415929
-328477
-253823
-183435
-95984
-74654
-76787
-168505
-226095
-354073
-471386
10
-420195
-388201
-294350
-217563
-149308
-61856
-42659
-38393
-123712
-183435
-319946
-443658
11
-390334
-358339
-262355
-185568
-119446
-31995
-10665
-8532
-93851
-153574
-290084
-411663
12
-369004
-334876
-232494
-166372
-98117
-6399
8532
19197
-72521
-130111
-266621
-383935
13
-351940
-317813
-211164
-149308
-78920
12798
25596
38393
-55457
-119446
-258089
-364738
14
-343408
-305015
-200499
-140776
-68255
29862
38393
51191
-42659
-115180
-251691
-354073
15
-345541
-305015
-198366
-140776
-61856
31995
49058
59723
-38393
-110914
-255956
-360472
16
-356206
-315680
-200499
-147175
-63989
29862
51191
57590
-40526
-130111
-275153
-381802
17
-377536
-339142
-211164
-159973
-72521
25596
42659
46925
-53324
-151441
-300749
-398865
18
-390334
-362605
-236760
-179170
-89585
10665
29862
27729
-76787
-179170
-313547
-411663
19
-398865
-375403
-262355
-209031
-119446
-10665
6399
0
-106649
-196233
-326344
-422328
20
-405264
-388201
-285818
-238893
-155707
-44792
-27729
-36260
-136510
-215430
-334876
-430860
21
-411663
-398865
-305015
-260222
-185568
-78920
-61856
-63989
-162106
-232494
-343408
-435126
22
-422328
-405264
-324211
-283685
-211164
-108781
-87452
-87452
-183435
-245292
-347674
-439392
23
-430860
-411663
-345541
-296483
-232494
-132244
-117313
-106649
-202632
-260222
-354073
-445791
24
-430860
-415929
-349807
-313547
-247425
-155707
-134377
-125845
-215430
-266621
-362605
-454323
Average
-408375
-388289
-306170
-255779
-184235
-91362
-72254
-67544
-161395
-219696
-332477
-429705
BACK MATTER
II
Table 12-3: Total fabric gains/losses. (Wall, roof, glazing, Floor)
Hour
January
February
March
April
May
June
July
August
September
October
November
December
1
-420006
-424072
-369928
-341483
-283178
-194799
-175412
-156168
-244557
-279480
-361658
-445815
2
-430671
-430471
-380592
-356414
-295976
-211863
-188210
-171099
-255222
-288011
-365924
-450081
3
-432804
-432604
-384858
-364946
-306641
-226794
-201008
-183897
-270153
-296543
-376589
-458613
4
-443469
-441135
-397656
-373478
-315173
-235326
-209540
-194562
-280817
-305075
-380855
-469278
5
-447735
-443268
-404055
-379876
-319439
-231060
-207407
-205227
-287216
-311474
-389387
-473544
6
-454134
-447534
-408321
-371345
-295976
-207597
-186077
-192429
-287216
-313607
-393653
-477809
7
-458400
-449667
-404055
-335084
-259716
-171337
-151949
-158301
-265887
-305075
-393653
-482075
8
-458400
-443268
-374194
-292425
-221322
-132943
-113556
-119908
-221094
-275214
-389387
-479942
9
-447735
-419806
-331534
-256164
-185062
-96683
-75162
-77248
-169903
-228288
-357392
-475677
10
-424272
-392077
-297407
-219904
-150934
-62555
-43168
-38855
-125111
-185629
-323265
-447948
11
-394411
-362216
-265412
-187909
-121073
-32694
-11173
-8993
-95249
-155767
-293403
-415953
12
-373081
-338753
-235550
-168712
-99743
-7098
8023
18735
-73919
-132305
-269941
-388225
13
-356017
-321689
-214221
-151649
-80546
12099
25087
37932
-56856
-121640
-261409
-369028
14
-347485
-308891
-203556
-143117
-69881
29162
37885
50730
-44058
-117374
-255010
-358363
15
-349618
-308891
-201423
-143117
-63483
31295
48550
59262
-39792
-113108
-259276
-364762
16
-360283
-319556
-203556
-149516
-65616
29162
50683
57129
-41925
-132305
-278473
-386092
17
-381613
-343019
-214221
-162313
-74147
24896
42151
46464
-54723
-153634
-304068
-403156
18
-394411
-366482
-239816
-181510
-91211
9966
29353
27267
-78185
-181363
-316866
-415953
19
-402943
-379279
-265412
-211372
-121073
-11364
5890
-461
-108047
-198427
-329664
-426618
20
-409341
-392077
-288875
-241233
-157333
-45492
-28237
-36722
-137908
-217623
-338196
-435150
21
-415740
-402742
-308071
-262563
-187195
-79619
-62365
-64451
-163504
-234687
-346728
-439416
22
-426405
-409141
-327268
-286026
-212790
-109481
-87960
-87913
-184834
-247485
-350994
-443682
23
-434937
-415540
-348598
-298824
-234120
-132943
-117822
-107110
-204031
-262416
-357392
-450081
24
-434937
-419806
-352864
-315887
-249051
-156406
-134886
-126307
-216828
-268815
-365924
-458613
Mean
-412452
-392166
-309227
-258119
-185862
-92061
-72763
-68005
-162793
-221889
-335796
-433995
III
Tender Submission | K13IDM
Table 12-4: Plant Sizing Peak Heating Load (W)
482075
PSR
1.2
Plant Heating Capacity (W)
578490
Plant Capacity (kW)
578
Table 12-5: Heating Degree Days, taken from CIBSE Guide A, Table 2.23
BACK MATTER
Month
Number of Heating Degree Days
January
314
February
290
March
255
April
192
May
105
June
45
July
16
August
18
September
51
October
124
November
228
December
293
Total
1931
IV
Table 12-6: Annual Energy Consumption and Carbon Emissions, using data from SAAP Building Regulations 2010, Table 12. Parameter
Value
Number of Degree Days
1931
Number of hours per day (h)
24
ÎŁđ?&#x2018;&#x2C6;đ??´ + 0.33NV
1330
Total Energy Used (kWh)
988504
Kg of Carbon per kWh
0.216
Total Carbon Used (Tonnes)
214
Price of Mains Gas per kWh (ÂŁ)
0.0348
Price of energy used (ÂŁ)
34, 400
V
Tender Submission | K13IDM
12.3
APPENDIX B Table 12-7: South Wall heat transfer (W) Example of Quasi-Dynamic Heat transfer calculation
Hour
Effective Time
Jan-29
Feb-26
Mar-29
Apr-28
May-29
Jun-21
Jul-04
Aug-04
Sep-04
Oct-04
Nov-04
Dec-04
1
6
-5055
-4958
-4103
-3712
-3014
-1853
-1654
-1447
-2522
-3080
-4189
-5432
2
7
-5116
-5004
-4163
-3818
-3104
-2003
-1775
-1568
-2628
-3125
-4249
-5462
3
8
-5146
-5034
-4209
-3878
-3180
-2124
-1865
-1673
-2718
-3185
-4295
-5522
4
9
-5236
-5079
-4329
-3954
-3240
-2169
-1941
-1764
-2809
-3261
-4355
-5628
5
10
-5266
-5094
-4374
-4014
-3195
-2049
-1835
-1794
-2869
-3306
-4415
-5673
6
11
-5312
-5124
-4390
-3848
-2803
-1626
-1428
-1492
-2839
-3306
-4460
-5703
7
12
-5357
-5139
-4148
-3335
-2351
-1144
-976
-1055
-2311
-3200
-4475
-5718
8
13
-5357
-4642
-3063
-2446
-1747
-571
-388
-196
-1135
-1994
-4385
-5703
9
14
-4196
-3541
-2007
-1436
-843
469
592
890
71
-652
-2485
-5583
10
15
-3065
-2652
-1118
-622
-59
1344
1346
1734
900
403
-1294
-3125
11
16
-2206
-1943
-455
-64
469
1932
1904
2337
1382
915
-646
-1964
12
17
-1920
-1476
58
238
785
2248
2160
2624
1714
976
-254
-1557
13
18
-1874
-1506
118
343
876
2308
2341
2684
1895
991
-495
-1602
14
19
-2327
-1702
-108
87
740
2143
2175
2518
1729
795
-902
-1949
15
20
-3035
-2199
-515
-335
363
1690
1813
2111
1277
312
-1566
-2989
16
21
-3970
-2983
-1269
-953
-195
1072
1271
1478
598
-517
-2591
-4949
17
22
-4799
-3993
-2143
-1647
-828
424
592
754
-276
-1406
-3782
-5130
18
23
-4890
-4521
-3003
-2280
-1220
77
246
196
-1060
-2311
-3903
-5236
19
0
-4935
-4642
-3364
-2642
-1582
-254
-86
-120
-1527
-2492
-3978
-5296
20
1
-4980
-4732
-3530
-2928
-1974
-662
-478
-527
-1753
-2612
-4038
-5356
21
2
-5025
-4808
-3666
-3094
-2230
-993
-780
-738
-1934
-2748
-4099
-5387
22
3
-5116
-4883
-3832
-3260
-2426
-1204
-991
-919
-2100
-2838
-4129
-5432
23
4
-5161
-4928
-3982
-3381
-2607
-1400
-1217
-1070
-2251
-2944
-4189
-5447
24
5
-5176
-4943
-4013
-3501
-2743
-1581
-1368
-1221
-2357
-3004
-4234
-5537
-4355.0
-3980.3
-2733.7
-2270.1
-1504.4
-246.9
-97.5
72.6
-980.2
-1732.9
-3225.4
-4640.9
Mean
BACK MATTER
VI
Table 12-8: Total Fabric heat transfer (W) Hour
Jan-29
Feb-26
Mar-29
Apr-28
May-29
Jun-21
Jul-04
Aug-04
Sep-04
Oct-04
Nov-04
Dec-04
1
-27958
-26862
-21541
-17888
-13090
-6560
-5617
-5726
-12487
-16725
-23458
-29997
2
-27944
-27178
-22161
-18951
-14568
-8354
-7107
-6996
-13557
-17353
-23648
-30129
3
-28115
-27467
-22920
-20047
-15800
-9764
-8415
-8166
-14484
-17864
-23798
-30160
4
-28408
-27757
-23556
-20706
-16675
-10854
-9435
-9034
-15283
-18393
-24138
-30344
5
-28634
-27921
-23898
-21285
-17331
-11670
-10212
-9834
-15931
-18775
-24447
-30889
6
-28458
-28091
-24487
-22212
-18218
-12429
-11266
-10771
-16736
-19213
-24508
-30787
7
-28793
-28284
-24806
-21915
-16808
-10683
-10269
-10095
-17100
-19462
-24894
-31050
8
-29008
-28455
-24794
-20883
-15250
-8952
-8513
-8900
-16651
-19513
-25140
-31320
9
-29382
-28464
-23660
-18945
-13813
-7373
-6728
-7151
-14507
-18957
-25261
-31625
10
-29277
-27446
-21385
-16940
-11620
-4572
-4111
-4651
-12024
-16872
-24700
-31626
11
-28202
-25755
-19364
-13051
-6489
1251
969
23
-9457
-14435
-23011
-30868
12
-26888
-24312
-16175
-9248
-3516
4532
4023
3421
-4696
-12235
-21318
-29052
13
-25664
-21740
-11926
-6336
-1214
6707
6519
6587
-1080
-7647
-19849
-27645
14
-22725
-18570
-8896
-3823
1044
9021
8816
9125
1815
-4570
-15153
-26519
15
-20520
-16898
-7288
-2334
2481
10420
10359
10556
3497
-2702
-13278
-22054
16
-19628
-16179
-6730
-2140
2914
10745
10751
11006
3768
-2392
-12918
-20856
17
-20234
-16491
-6949
-2807
2426
9935
10124
10360
3158
-3486
-13570
-21642
18
-21102
-17662
-8034
-3711
1591
8969
9341
9302
2254
-4827
-15134
-22665
19
-22051
-18826
-9583
-4905
895
8512
8355
8222
849
-6274
-16387
-23143
20
-23106
-20139
-11542
-6838
-633
6969
6730
6411
-1288
-8096
-17447
-24667
21
-24861
-21714
-13685
-9513
-3740
3509
3914
3520
-3696
-9962
-19359
-28181
22
-26825
-24145
-15720
-11759
-6398
581
1194
835
-5982
-12129
-22175
-28894
23
-27323
-25904
-18584
-13775
-8086
-1133
-636
-1179
-8435
-15175
-22690
-29376
24
-27688
-26467
-20697
-15835
-10005
-2955
-2569
-3186
-11295
-16066
-23095
-29672
VII
Tender Submission | K13IDM
Table 12-9: Ventilation Heat transfer (W) Hour
Jan-29
Feb-26
Mar-29
Apr-28
May-29
Jun-21
Jul-04
Aug-04
Sep-04
Oct-04
Nov-04
Dec-04
1
-266451
-269183
-235023
-217260
-180367
-124344
-112046
-99748
-155771
-177634
-229557
-282848
2
-273283
-273283
-241855
-226825
-188565
-135275
-120244
-109313
-162603
-183099
-232290
-285580
3
-274649
-274649
-244588
-232290
-195397
-144840
-128443
-117512
-172168
-188565
-239122
-291046
4
-281481
-280115
-252786
-237756
-200863
-150305
-133908
-124344
-179000
-194031
-241855
-297878
5
-284214
-281481
-256886
-241855
-203596
-147573
-132542
-131176
-183099
-198130
-247321
-300611
6
-288313
-284214
-259619
-236389
-188565
-132542
-118878
-122977
-183099
-199496
-250054
-303344
7
-291046
-285580
-256886
-213160
-165336
-109313
-97015
-101115
-169435
-194031
-250054
-306077
8
-291046
-281481
-237756
-185832
-140741
-84718
-72420
-76519
-140741
-174901
-247321
-304710
9
-284214
-266451
-210428
-162603
-117512
-61489
-47824
-49191
-107947
-144840
-226825
-301977
10
-269183
-248687
-188565
-139374
-95649
-39626
-27328
-24595
-79252
-117512
-204962
-284214
11
-250054
-229557
-168069
-118878
-76519
-20496
-6832
-5466
-60122
-98382
-185832
-263718
12
-236389
-214527
-148939
-106580
-62855
-4099
5466
12298
-46458
-83351
-170802
-245954
13
-225458
-203596
-135275
-95649
-50557
8198
16397
24595
-35527
-76519
-165336
-233657
14
-219993
-195397
-128443
-90183
-43725
19130
24595
32794
-27328
-73786
-161237
-226825
15
-221359
-195397
-127076
-90183
-39626
20496
31428
38260
-24595
-71053
-163970
-230924
16
-228191
-202229
-128443
-94283
-40992
19130
32794
36893
-25962
-83351
-176267
-244588
17
-241855
-217260
-135275
-102481
-46458
16397
27328
30061
-34160
-97015
-192664
-255519
18
-250054
-232290
-151672
-114779
-57389
6832
19130
17763
-49191
-114779
-200863
-263718
19
-255519
-240489
-168069
-133908
-76519
-6832
4099
0
-68321
-125710
-209061
-270550
20
-259619
-248687
-183099
-153038
-99748
-28695
-17763
-23229
-87450
-138008
-214527
-276015
21
-263718
-255519
-195397
-166702
-118878
-50557
-39626
-40992
-103847
-148939
-219993
-278748
22
-270550
-259619
-207695
-181733
-135275
-69687
-56023
-56023
-117512
-157138
-222725
-281481
23
-276015
-263718
-221359
-189931
-148939
-84718
-75153
-68321
-129809
-166702
-226825
-285580
24
-276015
-266451
-224092
-200863
-158504
-99748
-86084
-80618
-138008
-170802
-232290
-291046
BACK MATTER
VIII
Table 12-10: West Glazing unshaded solar gain (W) Example of solar cooling load Hour
Jan 29th
Feb 26th
Mar 29th
Apr 28th
May 29th
Jun 21st
Jul 4th
Aug 4th
Sep 4th
Oct 4th
Nov 4th
Dec 4th
07:30
1051
2365
4573
7253
8935
9723
8830
7043
5203
2838
1314
841
08:30
1367
2786
5308
8094
9671
10354
9566
7779
5887
3364
1629
841
09:30
1787
3416
6044
8777
10302
10880
10091
8462
6517
3994
2102
1261
10:30
2260
4100
6622
9250
10722
11300
10617
8935
7201
4520
2628
1682
11:30
2628
4520
7095
9671
11037
11563
10985
9250
7674
4941
2943
2102
12:30
3311
5308
7884
10459
11721
12194
11616
9934
8304
5729
3627
2628
13:30
4520
6570
9198
11878
12982
13508
12877
11300
9618
7043
4993
3837
14:30
8777
12089
15400
18448
19499
20078
18921
17555
16083
12772
9829
8094
15:30
10039
16030
20445
24440
25439
26122
24545
23126
21444
17029
12351
9723
16:30
8252
15663
22075
27226
28592
29486
27804
25228
23652
17082
11248
5887
17:30
4100
10985
19447
26963
29118
30379
28487
23862
21234
13981
5781
841
PEAK
10039
16030
22075
27226 29118 30379 28487 25228 23652 Table 12-11: West glazing shaded solar gain (W) Example of solar cooling load
17082
12351
9723
Hour
Jan 29th
Feb 26th
Mar 29th
Apr 28th
May 29th
Jun 21st
Jul 4th
Aug 4th
Sep 4th
Oct 4th
Nov 4th
Dec 4th
07:30
1050
2361
4563
7243
8933
9722
8829
7036
5192
2832
1313
841
08:30
1361
2770
5274
8050
9637
10326
9537
7744
5848
3343
1622
839
09:30
1769
3367
5944
8640
10179
10770
9985
8343
6401
3932
2076
1249
10:30
2194
3922
6279
8758
10248
10889
10196
8516
6796
4311
2528
1633
11:30
1970
2996
4362
5781
7201
7936
7463
5939
4520
3101
2011
1545
12:30
3311
5308
7884
10459
11721
12194
11616
9934
8304
5729
3627
2628
13:30
4520
6570
9198
11878
12982
13508
12877
11300
9618
7043
4993
3837
14:30
8777
12089
15400
18448
19499
20078
18921
17555
16083
12772
9829
8094
15:30
10039
16030
20445
24440
25439
26122
24545
23126
21444
17029
12351
9723
16:30
8252
15663
22075
27226
28592
29486
27804
25228
23652
17082
11248
5887
17:30
4100
10985
19447
26963
29118
30379
28487
23862
21234
13981
5781
841
PEAK
10039
16030
22075
27226
29118
30379
28487
25228
23652
17082
12351
9723
IX
Tender Submission | K13IDM
Table 12-12: Total Solar Gains accounting for shading (W) Hour
Jan-29
Feb-26
Mar-29
Apr-28
May-29
Jun-21
Jul-04
Aug-04
Sep-04
Oct-04
Nov-04
Dec-04
1
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
0
0
0
0
0
0
6
0
0
0
0
0
0
0
0
0
0
0
0
7
0
0
0
0
0
0
0
0
0
0
0
0
8
21910
36383
48797
62530
88279
104110
92134
66094
54458
42755
25606
19102
9
39266
56210
73908
87054
93381
103684
94306
82957
80263
70971
49191
21828
10
70915
87756
104959
112524
109403
113505
106278
104533
108357
105106
89878
55553
11
105372
118644
128615
131266
126666
129154
121857
123213
130088
133582
125953
101287
12
124441
132281
134317
133777
127803
129348
123148
126241
130949
136387
136347
122369
13
137007
149832
153093
152963
144259
145734
138925
141630
146250
145175
150365
134812
14
135250
146336
150161
150979
140674
142782
136801
138554
146655
142690
141415
129460
15
118303
137829
142750
141613
132276
133417
127769
131573
139987
137039
128038
116525
16
88561
119398
125140
123609
110905
110826
107156
112366
122211
120328
103797
89445
17
58886
87378
94904
77929
94177
105645
96773
77776
90769
88921
73097
46976
18
34162
54475
45529
86928
91748
99201
90974
80199
51436
60346
41603
19102
19
0
0
0
0
0
0
0
0
0
0
0
0
20
0
0
0
0
0
0
0
0
0
0
0
0
21
0
0
0
0
0
0
0
0
0
0
0
0
22
0
0
0
0
0
0
0
0
0
0
0
0
23
0
0
0
0
0
0
0
0
0
0
0
0
24
0
0
0
0
0
0
0
0
0
0
0
0
BACK MATTER
X
Table 12-13: Total Sensible Heat transfer (W) Hour
Jan-29
Feb-26
Mar-29
Apr-28
May-29
Jun-21
Jul-04
Aug-04
Sep-04
Oct-04
Nov-04
Dec-04
1
-412878
-415730
-361061
-331746
-273652
-186189
-167481
-149824
-237517
-273338
-355082
-438604
2
-422734
-421968
-371551
-346626
-286973
-203775
-180814
-164912
-248457
-281863
-359220
-442685
3
-424879
-424231
-376257
-355619
-298075
-219003
-193966
-177925
-263202
-290269
-369239
-450612
4
-435042
-432417
-388737
-364174
-306845
-227988
-202882
-188664
-273871
-298694
-373527
-460665
5
-439215
-434554
-395001
-370675
-311450
-224856
-201685
-199333
-280441
-304998
-381732
-465158
6
-444962
-438673
-399537
-363705
-290623
-203903
-182999
-188427
-281245
-307410
-385741
-469004
7
-387841
-379437
-334506
-268449
-194254
-107196
-89017
-94765
-200467
-238360
-324724
-411812
8
-304744
-275901
-196659
-104005
-7483
95578
101807
69458
-42704
-106618
-234014
-329604
9
-216490
-172966
-69532
17417
94016
191691
202697
188952
94021
26984
-119537
-261832
10
-101619
-53338
56780
139852
205218
297299
308299
309961
227455
164084
14697
-141044
11
-38452
6877
112066
192092
255247
346407
358567
360951
279388
222634
80096
-64943
12
1670
43670
148593
216172
279096
373569
380677
393038
304750
249351
113896
-16383
13
31253
79584
191356
254061
315619
409895
414742
429358
339458
272598
137279
15233
14
-82476
-31704
78519
139681
201357
302244
303953
317859
231796
154333
16141
-101930
15
23614
84267
197495
254609
323123
419057
429139
443010
353563
277303
123497
6485
16
-15106
56686
178469
230876
300212
394818
410893
422280
334085
243136
81851
-39137
17
-65126
2640
138144
172687
275099
384878
391987
377174
290189
190896
26811
-98184
18
-163964
-114551
2594
101613
194641
302248
312158
299371
166836
73915
-79494
-200328
19
-268374
-243436
-129573
-75547
13160
121448
137082
131027
24957
-65072
-195596
-291180
20
-336754
-317995
-214648
-166518
-83328
26919
42472
34257
-66218
-146063
-265954
-362002
21
-405833
-390843
-295960
-250335
-175474
-69527
-53330
-55699
-153717
-225122
-337165
-430867
22
-417667
-399196
-315760
-274294
-201819
-100090
-79738
-80097
-175741
-239133
-343929
-435528
23
-426061
-406876
-338364
-288154
-223247
-123518
-109203
-99876
-195961
-255996
-350366
-441932
24
-426426
-411388
-344425
-306005
-238984
-147053
-126928
-119649
-210664
-262810
-358666
-450124
Peak
31253
84267
197495
254609
323123
419057
429139
443010
353563
277303
137279
15233
XI
Tender Submission | K13IDM
12.4
APPENDIX C Table 12-14: Total pressure drop along pipes and method
Section of Duct
Q (m3/s)
Velocity (m/s)*
Duct CSA (m2)
Duct Diameter (m)
Pressure Drop per Unit Length (Pa)†
Duct Length (m)
Pressure Drop Along Pipe (pa)
1
16.30
10
1.63
1.44
0.5
4
2
2
14.51
10
1.45
1.36
0.6
3.6
2.16
3
12.73
10
1.27
1.27
0.6
3.6
2.16
4
10.95
10
1.09
1.18
0.7
3.6
2.52
5
9.16
10
0.92
1.08
0.8
3.6
2.88
6
7.38
10
0.74
0.97
0.9
3.6
3.24
7
5.60
10
0.56
0.84
1.1
3.6
3.96
8
3.81
10
0.38
0.70
1.4
3.6
5.04
9
2.03
10
0.20
0.51
2
3.6
7.2
10
0.89
4
0.22
0.53
0.35
13
4.55
11
0.45
4
0.11
0.38
0.5
9
4.5
Total Pressure Drop (Pa)
40.21
*values to prevent excessive fan power form CIBSE Guide B 2.3.11.4 [3] †From Chart 4.2 CIBSE Guide C [10]
BACK MATTER
XII
Table 12-15: Total Pressure loss calculations Component
Description
Component Loss Factor Îś*
Velocity (m/s)
Pressure Drop Due to Component (Pa)
Branch 1 - Unequal T
Configuration A, Flow ratio 0.9, Straight factor,
2
10
20
2
10
20
1.8
10
18
1.2
10
12
1.2
10
12
1
10
10
0.21
10
2.1
0.1
10
1
0.05
4
0.2
Estimate for higher diameter than table provides Branch 2 - Unequal T
Configuration A, Flow ratio 0.9, Straight factor, Estimate for higher diameter than table provides
Branch 3 - Unequal T
Configuration A, Flow ratio 0.9, Straight factor, Estimate for higher diameter than table provides
Branch 4 - Unequal T
Configuration A, Flow ratio 0.8, Straight factor, Estimate for higher diameter than table provides
Branch 5 - Unequal T
Configuration A, Flow ratio 0.8, Straight factor, Estimate for higher diameter than table provides
Branch 6 - Unequal T
Configuration A, Flow ratio 0.8, Straight factor, Estimate for higher diameter than table provides
Branch 7 - Unequal T
Configuration A, Flow ratio 0.7, Straight factor, Estimate for higher diameter than table provides
Branch 8 - Unequal T
Configuration A, Flow ratio 0.5, Straight factor, Estimate for higher diameter than table provides
Diverging flow - Unequal T
Configuration A, Flow ratio 0.4, Branch factor, Estimate for higher diameter than table provides
Smooth elbow
Value Assumed tended to at higher diameters
0.7
4
2.8
Diverging flow - Equal T
Configuration B, Flow ratio 0.5
0.67
4
2.68
Smooth elbow
Value assumed tended to at higher diameters
0.7
4
2.8 Total Pressure Drop from Components (Pa)
XIII
103.58
Tender Submission | K13IDM
BACK MATTER
XIV
XV
Tender Submission | K13IDM