Energy Analysis for 2 single-family Houses by Eleni Katrini

URBAN DESIGN BUILD STUDIO E N E R G Y A N A LY S I S of 2 HOUSES N E W C A S T L E G A R F I E L D

INDEPENDENT STUDY | CMU E L E N I K AT R I N I [ e k a t r i n i ] PROFESSOR: JOHN FOLAN

SPRING

2012

CONTENTS A__USEFUL TERMINOLOGY AND RATINGS B__NEW CASTLE

01. Site Analysis 02. Recommendations 03. IECC Guidelines 04. Baseline assemblies layers and specifications 05. Construction Details Recommendations 06. Energy Comparison of Baseline to First Proposals 07. Basement Alternatives 08. New scenario: Assemblies + HVAC sizing 09. Energy comparisons between different construction details 10. Final Decisions

C__GARFIELD

01. Assemblies and Construction Details 02. South Facade: R-Value and Thermal Bridges 03. REMRate Consumption Report 04. Different Scenarios Investigated

D__CONCLUSIONS E__APPENDIX: REPORTS

TERMINOLOGY

Load VS Energy Consumption: Load is the power needed from a system in order to work. Power is the rate at which energy is generated or used and it is measured in kW or BTUh. For example, the heating loads determined how much power does your heating system needs in order to run efficiently and heat the house. Another example is that a fluorescent bulb of 25 watts, needs 25 watts of power in order to function. Energy is how much power is being used by something over a certain period of time. Energy and energy consumption is being measured in kWh or BTUs.

2 3 4 5 4

Consequently, when we refer to loads we mean the power that it is demanded by a system in order to work and when we refer to energy we mean how much power actually the system is consuming over a period of time. “EUI, or energy use intensity, is a unit of measurement that describes a building’s energy use. EUI represents the energy consumed by a building relative to its size.” (Energy Star) EUI is a really important terminology when we are comparing several buildings and it is measured in kBTU/ft2. EUI is calculated by dividing the energy consumed in one year (kBTU) by the square footage of the building (ft2). EUI is important because it shows how much the building consumes per square foot, hence the measurement is not related to the building’s size. In that way it is possible to compare the performance of several buildings with different sizes by comparing their EUIs. The U.S. average EUI is 44 kBTU/ft2 . Thermal Boundary is the boundary where the building’s insulation is. For an energy simulation it must be defined what is included in the thermal boundary; meaning which spaces of the building are insulated. If we could imagine the insulation layer as a line going around and wrapping our building, in order to achieve high performance, that line should be closed and continuous. That means we would not have any thermal bridges and consequently our heat losses during the winter and our heat gain during the summer would be minimized. R VALUE AND U VALUE: The R-Value is the measure of thermal resistance; when a material has a big R-Value it is a better insulating material. The units it is measured in are ft2·°F·h/Btu. U-value is the overall heat transfer coefficient, and describes how a building material conducts heat. UValue is equal to 1/R-Value, hence the greater the U-Value the more easily the heat is transfered through a material. Materials with great U-factors are not good insulating materials. The units of the U-Value are Btu/ft2·°F·h. HERS score: RESNET has created HERS score as a rating system that helps in knowing just how energy efficient an already-built home is. The HERS score is a way of quantifying that information. A standard home would be 100 in the scale and an zero energy house would be between 20 and 0. A Energy Star certified building has an 85 HERS score. Whatever there is above 100 is not considered energy efficient.

USEFUL ENERGY TERMINOLOGY AND RATINGS HERS SCORE

High Performance Buildings

Zero Energy Buildings

NEW CASTLE

SUMMER

WINTER

LO T

SITE ANALYSIS

The plot has a North-West orientation and the houses will lead that orientation in order to be aligned with the street and continue the street front. The biggest liability of the plot are the West winds during the winter, and the biggest asset the SouthWest winds during the summer. Appropriate placing of massing and windows to protect from West winds and take advantage of the SouthWest ones

RECOMMENDATIONS A. South openings are really important, in order to let the solar radiation penetrate the building shell, heat the house and minimize heating loads during the winter months. On the contrary during the summer, the trees on the side of Madison Avenue and the entrance porch on SouthEast will ensure the shading during the summer months and the protection from West and East summer direct sunlight. Nevertheless the louvers of the porch must be on moving modules to give the opportunity of opening up during the winter so that they do not compromise the visual comfort of the residents. [figure 1]

moving or permanently open part to amplify visual comfort from the living room

B. On the West facades, the window area should be the minimum possible to prevent great heat losses due to infiltration and winter west winds.

b+d

C. For the above reasons, the entrance should be protect by the appropriate massing and orientation from the west winter winds. D. Incorporation of secondary uses on west-facing walls [stairs, bathroom, furniture walls] to block the heat losses E. Windows in general should be aligned in the internior part of the wall or in the middle to be protected from rain and moisture F. Based on the climate data, due to the increase relative humidity, a dehumidification system is necessary. Hence, the incorporation of an ERV system for ventilation would be more appropriate compared to an HRV.

c 9

IEEC 2009 GUIDELINES FENESTRATION DETAILS WINDOWS The windows maximum U-Value should be 0.35 Btu/ft²·°F·h. As far as climate sone 5 is concerned there is no definition for the SHGC.

WALL ASSEMBLY DETAILS ABOVE GRADE WALLS The wall assembly’s total insulation in a wood frame wall construction should have an R-Value of 20 ft²·°F·h/Btu. This means that both cavity and continuous insulation should succeed a calculated R-Value of 20 ft²·°F·h/Btu, without taking into consideration any other material or air gaps. Specifically, the cavity insulation should have an R-Value of 13 ft²·°F·h/ Btu and the continuous insulation 5 ft²·°F·h/Btu. The corresponding U value of the assembly should be 0.057 Btu/ft²·°F·h BELOW GRADE WALLS Unconditioned basement walls should be insulated from top of the basement down to 10 feet below grade or to the basement floor. They should have a continuous insulation of R10 ft²·°F·h/Btu and a cavity insulation of R13 ft²·°F·h/Btu. FOUNDATION WALLS The perimeter insulation around the foundation walls of a slab on grade should be of at least an R-value 10 ft²·°F·h/Btu and the should go at least 2 feet deep under the ground.

CEILING ASSEMBLY DETAILS ROOF WITH VENTED UNCONDITIONED ATTIC The roof assembly’s insulation R-Value should be 38 ft²·°F·h/Btu. This means that both cavity and continuous insulation should be equal or more than a calculated R-Value of 38 ft²·°F·h/Btu, without taking into consideration any other material or air gaps. The corresponding U value of the assembly should be 0.03 Btu/ft²·°F·h VAULTED VENTED ROOF Again the roof assembly’s insulation R-Value should be 38 ft²·°F·h/Btu.

INFILTRATION

Accepted infiltration should be considered when tested air leakage is less than 7 Air Changes per Hour (ACH) when tested with a blower door at a pressure of 33.5 psf (50 Pa)

BASELINE: ASSEMBLIES’ LAYERS + SPECIFICATIONS Basement Walls outer layer Rigid Foam Insulation Basement Walls outer layer Waterproofing Basement Walls Layer [Polyethylene] Rigid Foam Insulation outer layer CMU Rigid Foam blocksInsulation Waterproofing Layer [Polyethylene] inner layer Waterproofing Inside Air film Layer [Polyethylene] CMU blocks CMU blocks inner layer Inside Air film inner layer Inside Air film Slab below grade outer layer Rigid Foam Insulation Slab below grade outer layer Waterproofing Slab below grade Layer Rigid Foam Insulation outer layer Cast RigidConcrete Foam Insulation Waterproofing Layer Waterproofing inner layer Inside Air film Layer Cast Concrete Concrete inner layer Cast Inside Air film inner layer Inside Air film Exterior Walls outer layer Outside Air Film Exterior Walls Exterior Wallsouter layer Vinyl siding Outside Air Film outer layer Rigid Outside Air Insulation Film Foam Vinyl siding Vinyl Foam siding Insulation OSB Rigid RigidInsulation Foam Insulation Batt [14% Bridged] OSB OSB Insulation Tyvek [high density Batt [14%polyethylene] Bridged] Batt [14%polyethylene] Bridged] Gypsum Board TyvekInsulation [high density Tyvek [high density polyethylene] inner layer Inside AirBoard Film Gypsum Gypsum inner layer Inside AirBoard Film inner layer Inside Air Film Roof [attic] outer layer

inner layer

LAYERS LAYERS LAYERS

THICKNESS in 2 THICKNESS in THICKNESS in 0.006 2 2 8 0.006 0.006 8 8

LAYERS LAYERS LAYERS

THICKNESS in 2 THICKNESS in THICKNESS in 0.0056 2 2 4 0.0056 0.0056 4 4

R VALUE 10 R VALUE R VALUE 0.121 10 10 2.92 0.121 0.121 0.68 2.92 2.92 0.68 0.68 R VALUE

Initially, after the first baseline simulation the house was not meeting code. With new proposal and recommendations it will be attempted to minimize the energy performance of the building and meet the code.

10 R VALUE R VALUE 0.121 10 10 0.32 0.121 0.121 0.68 0.32 0.32 0.68 0.68 LAYERS THICKNESS in R VALUE 0.17 The tables on this page LAYERS THICKNESS in R VALUE LAYERS THICKNESS in R VALUE 0.006 0.61 0.17 show the baseline data of 0.17 0.75 3 0.006 0.61 0.006 0.61 0.438 0.47 0.75 3 the building’s assemblies, 0.75 3 based on the design team’s 5.5 21 0.438 0.47 0.438 0.47 0.02 0.75 5.5 21 first decisions. 5.5 21 0.5 0.45 0.02 0.75 0.02 0.75 0.68 0.5 0.45 0.5with attic 0.68 0.45 Roof Roof double space LAYERS THICKNESS in R 0.68 VALUE THICKNESS in R VALUE

Outside Air film Asphalt shingles Roofing felt OSB Air gap >= 25mm Mineral fiblr/wool [Batt high density] c.i. Mineral fiblr/wool [Batt] bridged 14% Tyvek [high density polyethylene] Gypsum Board Inside air film

0.39 0.039 0.438 3.5 6.5 0.02 0.50

0.17 0.44 0.47 1 11 19 0.75 0.45 0.68

0.39 0.039 0.438 3.5 6.5 0.02 0.50

0.17 0.44 0.47 11 19 0.75 0.45 0.68

REMRATE REPORT and CODE CERTIFICATION

CONSTRUCTION DETAILS RECOMMENDATIONS

lation continuous insulationRigid Foam Insulation

WALL ASSEMBLY DETAIL

cavity insulation [Continuous insulation], Rigid Foam Insulation

VAULTED ROOF ASSEMBLY DETAIL

3/4 inch [R3]

[Continuous insulation], 3/4 inch [R3]

Insulating in ﬂoor joists too, to avoid thermal bridges Insulating in ﬂoor joists too, to avoid thermal bridges

Cavity Insulation 3 1/2Insulation ” Cavity 3 1/2” Continuous 12”Continuous 12”

1 2 A

ROOF ASSEMBLY DETAIL

[2] Cavity Insulation 3 1/2”: Batt [R15] [2] Cavity Insulation 3 1/2”: Batt [R15] 1/2[R38-40] ” [R38-40] [1] or Loose Loose fill fill 12 121/2” [1]Continuous ContinuousInsulation: Insulation:Batt Batt12“ 12“ or Ventilating the the unconditioned unconditioned attic attic is is important, in order >>>> Ventilating order not not to to get get overheated overheated during duringthe thesummer summer A. Soffit Vent A. Soffit Vent B. Eave dam to protect from air in case of using Loose fill insulation instead of batt B. Eave dam to protect from air in case of using Loose fill insulation instead of batt

Comparison 1

Comparison 2

SIDING MATERIALS HVAC SYSTEMS

decrease

BASELINE with vinyl siding Features: 1. Vinyl Siding 2. Asphalt Shingles 3. Forced Air System RADIANT SYSTEM Features: 1. Metal Siding + Shingles 2. Boiler with radiant floor + 2 split systems for cooling

The 2nd comparison needed by the group was between different HVAC systems. The attempt was to evaluate the performance of a radiant floor (Case C), compared to a traditional air forced system (Baseline B). In case C, the HVAC included a hydronic boiler of an output capacity of 26 kBtus and efficiency of 84.5 AFUE. The boiler is connected to the radiant floor that distributes heat throughout the house. Cooling is being done through independent split systems of SEER 18. In case B the HVAC system consists of a gas furnace with 62 kBtuh output capacity and 93 AFUE. The air conditioning unit has a performance of 18.7 SEER. As we can see from the chart the energy consumption with the radiant system is significantly lower. 14

ANNUAL ENERGY CONSUMPTION

B B

decrease

BASELINE Features: 1. Metal Siding 2. Metal Shingles 3. Forced Air System BASELINE Features: 1. Metal Siding + Shingles 2. Gas Furnace with Air Handling Unit

ANNUAL ENERGY CONSUMPTION

66.2 64.8

The design team wanted to pursue the implementation of metal on the outer layer of the building. However, that might cause implications, such as the building envelope getting overheated and increasing the cooling loads during the summer. Towards this direction two simulations have been done: in case A the siding was vinyl and the shingles asphalt, and in case B both the siding and the shingles were metal. By comparing the two simulation runs, the differences between the energy consumptions are insignificant. Consequently the students could keep the metal siding for their project.

66.3 66.2

SIMULATION STUDIES REALIZED IN REMRATE software VERSION V12.96

ANNUAL ENERGY CONSUMPTION

decrease

66.2 60.5

ENERGY COMPARISON OF BASELINE TO FIRST PROPOSALS

40 30 20 10 0

Comparison 4

INCREASED INSULATION INCREASED INS. + HVAC 70

60 50 40 30

11%

decrease

INCREASED INSULATION: 1. Wall: Rigid Foam 4” - R20 2. Floor: Batt Insulation: 5 1/2 “ - R21 RADIANT +MORE INSULATION: 1. Wall: Rigid Ins: 4” - R20 2. Floor: Batt Ins: 5 1/2 “ - R21 3. Radiant floor system + mini splits

ANNUAL ENERGY CONSUMPTION

66.2 58.7

Comparison 3

Based on the first baseline (B) created by the design team, the wall detail had 2”x 6” studs, 16 o.c. , 5 1/2 “ batt cavity insulation (R21) in the between and 3/4” rigid foam continuous insulation (R3) on the outside. The U value of the wall assembly was 0.046 BTU/h °F ft2. The floor between the conditioned space and the unconditioned basement had 3 1/2” batt insulation of R15. In order to explore the possibilities in energy reduction based on a better building envelope, a simulation was done of case D with 4” of rigid foam continuous insulation on the outside layer of the walls (R20) and 5 1/2 batt insulation (R21) in the floor between basement and conditioned space. As we can see on the chart, there is a significant reduction in energy consumption.

B B

BASELINE Features: 1. Wall: Rigid Foam 3/4” - R3 2. Floor: Batt Insulation: 3 1/2 “ - R15 BASELINE Features: 1. Wall: Rigid Ins 3/4” - R3 2. Floor: Batt Ins: 3 1/2 “ - R15 3. Forced Air System

In the last simulation case C and D were combined in scenario E. That means that for scenario E, the building had both increased insulation and a radiant floor system. This simulation was done in order to explore the possibilities of minimizing the energy consumption. Scenario E is compared to the baseline B, with less insulation and a forced air system, and as it is expected there is a decrease in energy consumption from B to E.

20 10 0

CASES A, B, C, D AND E on the HERS SCORE HERS INDEX In the simulation results of REMRATE, the HERS score is reported. Based on the results of all the simulations, the five different cases were identified on the HERS scale. Cases A, B and C have almost the same ranking on the scale. Case A and baseline B have a HERS score of 60 and case C has 61. For cases D and E, the HERS score has dropped to 58. That was expected because both cases D and E had an increased insulation, hence the losses were minimized and their energy performance was optimized. In order to achieve an even better performance, additional actions should be taken. Possible design actions would be : 1. Eliminate the thermal bridges, 2. Maximize as possible the performance and R-Values of the assemblies 3. Re-size the HVAC systems according to the houseâ&#x20AC;&#x2122;s heating and cooling loads.

BASEMENT ALTERNATIVES 100 90

ENERGY USE INTENSITY After meeting the client, the design team was considering ANNUAL MBtus per sq ft the option of eliminating the basement from their proposed

80 70 60 50 40 30 20 10 0 16

52.1

56.8

59.0

design, for economic reasons. Three different simulations were processed in order to evaluate the changes on the energy performance of the building. The first option was the building with a full basement (baseline B), the second case (F) was with a half basement and finally the third option was without basement at all (case G). As we can see in the chart in the left, taking out the basement and exposing the slab on grade, increased the Energy Use Intensity of the building, which means that the energy consumption of the building increased.

However, due to the fact that the increase is not that significant, and due to the economic limitations, the group decided to eliminate the basement. In that case, the buildingâ&#x20AC;&#x2122;s assemblies had to change in order to make the building envelope tighter. Moreover based on the previous simulations, Full Basement Half Basement No Basement the HVAC system selected was the boiler with the radiant (baseline B) (baseline F) (baseline G) floor and the mini split systems for cooling.

NEW SCENARIO: ASSEMBLIES + MECHANICAL SYSTEMS In all the above simulations, REMRate software showed that the building was not meeting all versions of the IECC code. Moreover, due to several changes along the designing process, a new scenario had to be determined. The adjustments made were related to the buildingâ&#x20AC;&#x2122;s assemblies and mechanical systems. The new details for the building were as follows:

ASSEMBLY DETAILS R VALUE Slab Walls Roof (Part A) vaulted part above double-height space Roof (Part B) Windows SHGC: 0.45

U VALUE 10.00 21.74 55.56 52.63 3.03

0.100 0.046 0.018 0.019 0.330

MECHANICAL SYSTEMS [HVAC] Based on the model made with the above data, the heating and cooling loads changed, hence the mechanical systems should be defined to avoid having an oversized system that would consume a lot. The heating load was 18,000 kBTUh and the cooling load was 10,500 kBTUh. As 1 ton is 12,000 BTUh, an 1.5 ton system would be required for heating and an 1 ton system for cooling. Research among different boilers was made in order to define an 1.5 ton boiler that would have increased efficiency (AFUE). Two boilers were identified: Peerless Purefire PF50 with an AFUE of 95.09% and Buderus GB 142/24 by Bosch with an AFUE of 96%. BAsed on the right sizing and efficiency Buderus boiler was chosen. For the cooling of the house split systems are going to be installed. The system will include two compressors (exterior units) and five evaporators. The model selected is a wall mounted system of high efficiency by DAIKIN. The model number is RKS09JEVJU it has a cooling capacity of 8,500 BTUh and efficiency of 18 SEER.

A. Buderus GB 142/24 B. DAIKIN compressor C. DAIKIN evaporator

For ventilation purposes, an ERV system will be installed in the house. However, ERV systems can be oversized for a single family house. Hence, research for the smallest ERV system was made based on the list of Certified Heat and Energy Recovery Ventilators published by the Home Ventilating Institute (www.hvi.org). The ERV system selected is BR70 by RENEWAIRE LLC.

A C

Finally, for domestic hot water (DHW) a gas tankless water heater is proposed. The model used for the simulation is SCTH-95DVN by RHEEM MFG. CO. and it is certified by Energy Star. The water heater has an energy factor of 0.94. 17

3.5 feet

2” rigid board perimeter

4” rigid board under slab

4” under slab + 2” perimeter

ENERGY COMPARISONS BETWEEN CONSTRUCTION DETAILS

Rigid Insulation R10 [2 inches] Rigidboard board Insulation R10 [2”] Poured concrete Poured condrete

A. PERIMETER INSULATION

SLAB ON GRADE INSULATION

Rigid board Insulation R20 [4”] Rigid board Insulation R20 [4 inches]

Rigid board Insulation [4”] Rigid board Insulation R20 [4R20 inches]

Poured concrete Poured condrete

Rigid board Insulation R10 [2R10 inches] Rigid board Insulation [2”] Poured concrete Poured condrete

B. INSULATION UNDER THE SLAB C. PERIMETER+UNDER SLAB

ENERGY USE INTENSITY ANNUAL MBtus per sq ft

47.1

46.8

55.5

MBtus/ft -yr

After the assemblies and the mechanical systems were identified in order for the building to meet code, several simulations were realized for further optimization. In those simulations the above new baseline is scenario H.

30 20 10 0 18

H I J

SLAB INSULATION In order to investigate which is the most energy efficient way to insulate the slab, 3 scenarios were explored.In scenario H, the slab has a 2” rigid board insulation [R10] on the perimeter of the outer side of the foundation walls, which goes down 3.5 ft under the slab. In scenario I, the slab is insulated underneath with a 4” rigid board insulation [R20]. In scenario J, the slab is both insulated underneath with a 4”rigid board insulation [R20] and on the perimeter with a 2” rigid board insulation [R10]. The rest of the assemblies: vaulted roof, roof with attic and walls were kept the same: Walls: R3 Continuous insulation [3/4” rigid board] + R21 Cavity insulation [5 1/2” batt insulation] Roof [attic+vaulted part]: R15 Cavity insulation [3 1/2” batt insulation] + R38 Continuous insulation [12” batt insulation] By looking at the results, the highest energy use intensity is encountered in scenario I with 55.5 MBtus/sq ft per year and the lowest in scenario J with 46.8 MBtus/sq ft per year. Hence we realize the importance of perimeter insulation. Even though it is possible to eliminate the under-slab insulation, it would be advisable, if the budget allows it, to put a 1” rigid board insulation [R5] under the slab as a moisture control. If water barrier is applied under the slab, the under slab insulated can be omitted. Finally, if the perimeter insulation is to be minimized, its depth under the slab into the ground shouldn’t be less than 2ft.

MBtus/sqft-yr

ENERGY USE INTENSITY ANNUAL MBtus per sq ft

44.0 3” RIGID BOARD [R12]

43.3

45.1

2” RIGID BOARD [R8]

47.1

WALL INSULATION DETAILS

30 WALL INSULATION

H 4” RIGID BOARD [R16]

3/4” RIGID BOARD [R3]

Having calculated the Energy Use intensity of the different slabs, we will use Scenario A as our baseline in order to evaluate the energy benefits of adding extra continuous insulation to our wood frame walls. In scenario A the walls included 5 1/2” of batt insulation between the joists, and continuous insulation externally of 3/4” rigid board. As we can from the chart on the right, the more the continuous insulation, the less the EUI, something which was totally expected. However, if we notice the changes in EUI between 3/4” - 2”, 2” 3” and 3”- 4” they are: -2.0 MBtu/sqftyr, -1.1 MBtu/sqft-yr and -0.7 MBtu/ sqft-yr. Therefore we realize that after a point of adding insulation the differences are not significant, hence the action is not cost effective. An exterior continuous insulation is necessary as proven earlier, and it is really important in order to avoid all the thermal bridging of the cavity insulation due to the joists. Hence, a 3/4” rigid board or even better a 2” rigid board insulation is preferred if it possible based on the budget limitations.

MOVING TOWARDS THE LAST DECISIONS Based on the simulations for the slab insulation the best options between which a decision should be made are scenario H and K. As far as the wall insulation is concerned the best and more cost-efficient options between which a decision should be made are the 3/4” or the 2” continuous insulation. The next step will be to look in REMRate’s reports for the answer. 19

FINAL DECISIONS REMRATE REPORT SCENARIO H

Based on the above REMRate report of scenario H, we can see that the building meets the code IECC 2012 and actually it surpasses the requirements by 10.4%. However, that doesn’t mean that all of the individual parts and assemblies of the house meet the code. In the breakdown of the assemblies above, we can see that the UA of the windows and of the slab are higher than the code’s requirements. However IECC works with trade-offs, hence even if not all of the requirements are met the building can still pass the code. From the last simulations, 2 decisions should be made: A. If there is going to be under-slab insulation and B. If 2” continuous insulation on the walls is needed. Based on the report we can see that the slab does not meet the code, hence it would be advisable to add the under-slab insulation if there are no economic restrictions. In that way the performance of the building is going to improved, as we saw also on the simulations above. As far as the extra continuous insulation on the walls is concerned, as it is obvious from the report, it will not be needed, as the350 walls with a 3/4” continuous insulation are meeting the code. Pella Windows: Series________________________________________________________________________________________________ Finally, for a better performance for the windows the following models by Pella Windows 350 Series are proCASEMENT/AWNING posed. TYPE OF WINDOW U-FACTOR SHGC VLT% TYPE OF WINDOW U-FACTOR | SHGC | VLT% 1

11/16” Advanced Low-E IG with 3mm glass (vent)

0.28

0.24

11/16” SunDefense Low-E IG with Argon with 3mm glass (vent)

0.24

0.17

11/16” Advanced Low-E IG with 3mm glass (vent-foam insulation)

0.28

0.24

11/16” SunDefense Low-E IG with 3mm glass (vent-foam insulation)

0.27

0.18

11/16” Advanced Low-E IG with 3mm/5mm glass (vent)

0.29

0.23

11/16” SunDefence Low-E IG with 3mm/5mm glass (vent)

0.29

0.18

11/16” Advanced Low-E IG with 3mm/5mm glass (vent-foam insulation)

0.29

0.23

11/16” SunDefense Low-E IG with 3mm/5mm glass (vent-foam insulation)

0.29

0.18

1” Advanced Low-E IG with 5mm glass (vent)

0.28

0.23

10 1” Advanced Low-E IG with argon with 5mm glass (vent)

0.25

0.23

11 1” NaturalSun Low-E Triple-pane IG with 3mm glass

0.23

0.37

20 Notes: From the windows selection above, the windows with the lower U-Factor for better insulation and with higher Visual Lighting

From the windows selection above, the better performing windows are the triple pane ones (number 11), which have the lowest U-Factor for better insulation and the highest Visual Lighting Transmission for better visual quality. However, just because they are more expensive than the double pane the second better selection would be the 1â&#x20AC;? Advanced Low-E IG with Argon with 5mm glass (number 10). Those ones have a lower SHGC too, which means that the windows are not going to get overheated during the summer. Finally, if for economic reasons windows without argon gas are preferred, I would suggest either number 9 or number 4, because they are the ones with the better U-factors. For better visual quality between the two (VLT= 43%) number 9 should be selected.

MBtus/ft2-yr

SCENARIO H vs SCENARIO K 50

EUI (mBtus/ft -yr) 2

40 35 30

25 20 15 10 5 0

H K

Based on the above a final simulation was realized (scenario K), where both perimeter and under slab insulation were implemented and the windows applied were selection 11 from the Pella list provided above. Scenario H and K were compared in order to quantify the improvement in performance by the above design decisions.

HERS score

for scenarios H+K SCENARIO K: FINAL REMRATE REPORT - HERS SCORE

G A R F I E L D

ASSEMBLIES AND CONSTRUCTION DETAILS ASSEMBLIES LAYERS The project in Garfield is a 1920 ft2 single family house, which is two stories high. It has an almost true South-North orientation, with the North facade being on the street access. It is a wood frame construction with concrete blocks on the basement walls. The South and North facades are following a different construction from the East and West ones; they have big windows coming in prefabricated modules and being placed on the facade. The layers of the assemblies as well as their RValues are given on the table on the side. After the simulation, REMRate verified that the house meets the IECC 2012 code and can be certified. However the EUI of the house is 40.05 kBtu/ft2 and its HERS score is 71. That means that there is space for improvement. Firstly, it is really important to keep the layer of insulation as continuous as possible in order to minimize thermal bridges. Even though there might be an insulation break, all the pieces should be aligned. However the most important thing affecting the performance of the building is the North and South facade construction.

Assembly (from Interior to Exterior) Thickness R-Value [F hr 2/Btu] Wall (East+West) Gypsum Board 3/4" 0.45 Ba Insula on 5 1/2" 21 Framing 2x6 - 16" OC 6" OSB Seathing 3/4" 0.47 2" 10 XPS Insula on Metal Siding 1" 0.61 -non framing part Wall (South + North) Plywood siding 3/4" 0.47 Ba Insula on 5 1/2" 21 Plywood siding 3/4" 0.47 Basement Wall XPS Insula on 2" 10 Concrete Block 6" 2.92 2" 10 XPS Insula on Slab Concrete Slab 5" 0.4 Polyethylane 10 mil 0.12 XPS Insula on [edge] 4" 20 Roof Metal roofing 1" 0.61 OSB Seathing 3/4" 0.47 Fiberglass Ba insula on 11 7/8" 38 Wood joist 16" OC 11 7/8" 0.47 Plywood Interior finish 3/4"

SOUTH FACADE: R-VALUE AND THERMAL BRIDGES

On the drawing above we can see the changes in the U-Value on the South Facade. The darker the orange the bigger the U-Value, and hence the bigger the heat losses. Moreover, it must be taken into consideration that wherever there is a change in color there is a thermal bridge. To minimize the thermal bridging in the framing part of the construction, and in order to prevent condensation, both 2â&#x20AC;? of rigid foam insulation should be placed on the outer side of the assembly. (Detail A)

keeping the thermal boundary continuous

DETAIL A

Joists U Value: 0.039 U Value: 0.044 U Value: 0.078 U Value: 0.28

old detail

new detail

REMRATE CONSUMPTION REPORT

COMPONENT CONSUMPTION SUMMARY Date:

COMPONENT CONSUMPTION SUMMARY

May 19, 2012

Rating No.:

From theName: REMrate report below, it is obvious the effect ofRating the facades and windows in the energy consumption, Building Garfield_UDBS Org.: especially during the winter (heating season). What the chart shows is that for the biggest part of energy conOwner's Name: Phone No.: sumption, Property: Above grade walls and windows/skylights are contributing Rater's Name: the most. Address:

Rater's No.:

However, due to design decisions, and as far as the building is meeting the code and surpassing it, the construcBuilder's Name: tion of the SouthPittsburgh, and North walls should not be changed. Further on, three simulations will be done in order Weather Site: PA Rating Type: toFile explore possible effects from: a.increase in roof insulation, b. increase in West and East walls insulation and Name: BASELINE_051612.blg Rating Date: finally c.re-sizing of the mechanical systems appropriately based on the buildingâ&#x20AC;&#x2122;s design loads. Heating Season

4.6

Ceilings/Roofs Rim/Band Joists Above Grade Walls

14.4

14.4 mmBtus/year

14.8

14.8 mmBtus/year

2.7

Foundation Walls

2.1

Doors Windows/Skylights Frame Floors Crawl Space/Unht Bsmt Slab Floors

2.9

Infiltration

2.8

Mechanical Ventilation 1.5

Ducts Active Solar Sunspace -14.2

Internal Gains

31.5

Total -30

-20

-10

MMBtu/yr

REM/Rate - Residential Energy Analysis and Rating Software v12.96

This information does not constitute any warranty of energy cost or savings. ÂŠ 1985-2011 Architectural Energy Corporation, Boulder, Colorado.

DIFFERENT SCENARIOS INVESTIGATED COMPARISON BETWEEN DIFFERENT SCENARIOS

Baseline

EUI (mBtus/ft2-yr) Baseline with 2 extra inches of con-

MBtus/ft2-yr

tinuous rigid foam insulation on the exterior of the West and East walls Baseline with 2 extra inches of continuous rigid foam insulation on the exterior side of the roof Baseline with 4 extra inches of continuous rigid foam insulation on the exterior side of the roof Baseline with right-sized HVAC: a 36,000 Btu Furnace with 95 AFUE and a 1,5 ton sir conditioning unit with 18.5 SEER efficiency

38.2

40.0

39.1

39.5

39.2

40.1

25 20 15

Scenario with all the above design actions of Scenario A, C and D. [2â&#x20AC;? more of wall insulation, 4â&#x20AC;? more on roof insulation + new HVAC]

10 5 0 Baseline

Scenario A Scenario B Scenario C Scenario D Scenario E

Based on the above, it is obvious that the changes propose did not have a great impact on the Energy Use Intensity of the house. Consequently, there is not a demanding action to be taken. The proper sizing of the HVAC would be helpful for the general performance of the house. What would make a difference in the building would be to construct the North and South facades as air tight as possible. Due to the high possibility of leakage through those facades, a moderate ACH of 0.50 @ 50 Pascals was modelled for the simulation. With a proper tight construction, the infiltration rates will be lower.

ERFORMANCE WITH ENERGY STAR

ENERGY RATING CERTIFICATE HERS Score for Baseline HVAC: Further Information Required

The design team had not defined a model for Domestic Hot Water. In the simulation a 40 gallon storage water heater by A.O. SMITH Water Products, with 0.62 Energy Factor, was used. (model number: 153.331140).

This Home

The modelled HVAC the simulation where selected by the dataEstimated Annual Energyfor Consumption base of certified products of AHRI (Air-Conditioning, Heating and MMBtu/yr Refrigeration Institute). The gas furnace is from Nordyne LCC, has a 120 capacity of 36,000 Btu and its 98.0 efficiency is 95 AFUE. (model number: 100 FG7SD 038D-24B). 80 The 60 air52.3 conditioning unit is 1.5 ton, has an efficiency of 18.5 SEER and it 40 24.5 is a Lennox model. number: CX34-18/24+TDR) 19.0 (model 20 0

2.2

Total

Photovoltaics

Lights & App

Water Heating

Cooling

Heating

For further information, the AHRI database is available here: http://www.ahridirectory.org/ahridirectory/pages/home.aspx

27 Annual Estimates*:

TITLE

CONCLUSIONS Through the investigation of the above two houses, great insight was generated. Both of them have a really good energy performance that lies around the typical performance of a residential building in U.S. and below that. Taking a closer look to the simulation results from both the houses above, we will notice that the energy performance of the house in Garfield could be defined as better than the house in New Castle, as it has a lower EUI. However, based on code and rating systems, New Castle has a way better rating reaching 48 and 46 on the HERS Score while Garfield is at 70. That difference is due to the difference in size between the two buildings. Garfield has a bigger annual energy consumption, but as it is quite bigger than the New Castle house its EUI comes out smaller. That is why the New Castle house on the other hand is rated better, because firstly it is smaller but also is consuming less in total. Size, material and spatial conservation are always really important factors in the rating systems. Towards this end, the decision of both the design teams to minimize their space by taking out the basements were really wise. I hope this study will be of assistance both the projects towards the final steps of their realization.

A P P E N D I X

NEW CASTLE REPORTS

ACTION REPORT Date:

May 19, 2012

Rating No.:

Building Name:

New Castle

Rating Org.:

Owner's Name:

Habitat for Humanity

Phone No.:

Property:

Rater's Name:

Address:

New Castle, PA 16102

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

FINAL OF THE FINALS_PERIM+UNDER SLAB INS_PELLA Rating Date: WINDOWS.blg

Builder's Name:

Heating Cost ($/yr)

Cooling Cost ($/yr)

80 60 40 20 0 -20 -40 -60

0 -50

29 0

-44 Internal Gains

Other

Doors

Ceilings/Roofs

Windows/Skylights

Slab Floors

Mechanical Ventilation

Above Grade Walls

-56

Annual Energy Cost ($/yr) Lights & App 452 Cooling 45 Water Heating 66

Heating 144

Service Charge 259

Total 965

Other

Ceilings/Roofs

100

$/yr

Windows/Skylights

$/yr

COMPONENT CONSUMPTION SUMMARY Date:

May 19, 2012

Rating No.:

Building Name:

New Castle

Rating Org.:

Owner's Name:

Habitat for Humanity

Phone No.:

Property:

Rater's Name:

Address:

New Castle, PA 16102

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

FINAL OF THE FINALS_PERIM+UNDER SLAB INS_PELLA Rating Date: WINDOWS.blg

Builder's Name:

Heating Season

2.4

Ceilings/Roofs Rim/Band Joists

13.9

Above Grade Walls Foundation Walls 0.9

Doors

4.0

Windows/Skylights Frame Floors Crawl Space/Unht Bsmt

7.1

Slab Floors 0.1

Infiltration

7.1

Mechanical Ventilation Ducts Active Solar Sunspace Internal Gains

-10.0 25.5

Total -10

10 MMBtu/yr

COMPONENT CONSUMPTION SUMMARY New Castle

Page 2

Cooling Season

0.0

Ceilings/Roofs Rim/Band Joists -0.1

Above Grade Walls Foundation Walls

-0.0

Doors

0.9

Windows/Skylights Frame Floors Crawl Space/Unht Bsmt -0.3

Slab Floors

-0.0

Infiltration -0.2

Mechanical Ventilation Ducts Active Solar Sunspace

1.8

Internal Gains -0.7

Whole House Ventilation

1.3

Total -1

1 MMBtu/yr

2012 IECC OVERALL BUILDING UA COMPLIANCE Date:

May 19, 2012

Rating No.:

Building Name:

New Castle

Rating Org.:

Owner's Name:

Habitat for Humanity

Phone No.:

Property: Address:

Rater's Name: New Castle, PA 16102

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

FINAL OF THE FINALS_PERIM+UNDER SLAB INS_PELLA Rating Date: WINDOWS.blg

Builder's Name:

Elements

Insulation Levels 2012 IECC

As Designed

Shell UA Check 24.3

17.5

Above-Grade Walls:

Ceilings:

115.5

93.3

Windows and Doors:

83.3

60.6

Slab Floor, Heated: Overall UA (Design must be equal or lower):

8.4

4.5

231.5

176.0

0.480

0.230

Window U-Factor Check (Section 402.5) Window U-Factor (Design must be equal or lower):

This home MEETS the overall thermal performance requirements and verifications of the International Energy Conservation Code based on a climate zone of 5A. (Section 402, International Energy Conservation Code, 2012 edition.) In fact, this home surpasses the requirements by 24.0%.

Building Elements

Type

U-Value

Area

Ceilings Roof

R-40 BATT

0.019

549.0

Roof

R-40, Vaulted*

0.018

386.0

Wall

R-21, R-3 Cont.*META7

0.046

2026.4

Joist

JOISTS BATT INS

0.065

40.5

Window

PELLA WINDOWS

0.230

52.0

Window

PELLA WINDOWS

0.230

24.0

Window

PELLA WINDOWS

0.230

56.5

Window

PELLA WINDOWS

0.230

41.0

Window

PELLA WINDOWS

0.230

16.0

Window

PELLA WINDOWS

0.230

8.0

Window

PELLA WINDOWS

0.230

42.2

Door

2-1/4 Wd solid core

0.268

20.5

Above-Grade Walls

Windows and Doors

Building Elements

Type

U-Value

Area

0.031

145.0

Slab Floor, Heated On-Grade Perimeter

SLAB ON GRADE_PERIME

REM/Rate - Residential Energy Analysis and Rating Software v12.96 ÂŠ 1985-2011 Architectural Energy Corporation, Boulder, Colorado.

HOME CERTIFIED TO MEET THE PROVISIONS OF THE 2012 INTERNATIONAL ENERGY CONSERVATION CODE This home built at

, New Castle, PA by

exceeds the minimum requirements for the 2012 International Energy Conservation Code

Building Features Ceiling Flat: R-53 Vaulted Ceiling: U-0.018 Above Grade Walls: U-0.046 Foundation Walls: NA Exposed Floor: NA

Duct: NA Window: U-Value = 0.230, SHGC = 0.370 Heating: Fuel-fired hydronic distribution, Natural gas, 96.0 AFUE. Cooling: Air conditioner, Electric, 18.0 SEER. Water Heating: Instant water heater, Natural gas, 0.94 EF, 0.0 Gal.

Slab: R-10.0 Edge, R-20.0 Under The organization below certifies that the proposed building design described herein is consistent with the building plans, specifications, and other calculations submitted with the permit application. The proposed building has been designed to meet the 2012 IECC requirements in compliance with Chapter 4 based on Climate Zone 5A and with all mandatory requirements. Name: Organization:

Signature: Date: May 19, 2012

The 2012 International Energy Conservation Code is a registered trademark of the International Code Council, Inc. ( â&#x20AC;&#x153;ICCâ&#x20AC;?). No version of this software has been reviewed or approved by ICC or its affiliates. REM/Rate - Residential Energy Analysis and Rating Software v12.96

HOME PERFORMANCE WITH ENERGY STAR ENERGY RATING CERTIFICATE

Estimated Annual Energy Cost

Estimated Annual Energy Consumption MMBtu/yr

Address: New Castle, PA 16102 House Type: Single-family detached Cond. Area: 1425 sq. ft. Rating No.: Issue Date: May 19, 2012

Annual Estimates*: Electric(kWh): 4230 Natural gas(MCF): 44 C02 emissions(Tons): 5 Annual Savings**: $781 * Based on standard operating conditions ** Based on a HERS 130 Index Home

17.0

1.3

TITLE Company Address Certified Rater: Certification No: Rating Date:

REM/Rate - Residential Energy Analysis and Rating Software v12.96 This information does not constitute any warranty of energy cost or savings. ÂŠ 1985-2011 Architectural Energy Corporation, Boulder, Colorado. The Home Energy Rating Standard Disclosure for this home is available from the rating provider.

Total

Heating

Total

Service Charge

12.8

Photovoltaics

This Home

56.7

Lights & App

258.6

70 60 50 40 30 25.6 20 10 0

Water Heating

965.6

Photovoltaics

Lights & App

Water Heating

Cooling

Heating

1200 1000 800 600 452.1 400 200 144.4 44.9 65.6 0

Cooling

$/yr

GARFIELD REPORTS

ACTION REPORT Date:

May 19, 2012

Rating No.:

Building Name:

Garfield_UDBS

Rating Org.:

Owner's Name:

Phone No.:

Property:

Rater's Name:

Address:

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

BASELINE_051612.blg

Rating Date:

Builder's Name:

Heating Cost ($/yr)

Cooling Cost ($/yr)

$/yr

214 43

20 0 -20

-24 Internal Gains

Windows/Skylights

-40

Other

Foundation Walls

Infiltration

Slab Floors

Ceilings/Roofs

-159 Above Grade Walls

Annual Energy Cost ($/yr) Lights & App 832 Cooling 31

Service Charge 259

Water Heating 274 Heating 467

Total 1862

Other

Ceilings/Roofs

220

Windows/Skylights

300 200 100 0 -100 -200 -300

$/yr

COMPONENT CONSUMPTION SUMMARY Date:

May 19, 2012

Rating No.:

Building Name:

Garfield_UDBS

Rating Org.:

Owner's Name:

Phone No.:

Property:

Rater's Name:

Address:

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

BASELINE_051612.blg

Rating Date:

Builder's Name:

Heating Season

4.6

Ceilings/Roofs Rim/Band Joists

14.4

Above Grade Walls 2.7

Foundation Walls

2.1

Doors

14.8

Windows/Skylights Frame Floors Crawl Space/Unht Bsmt Slab Floors

2.9

Infiltration

2.8

Mechanical Ventilation 1.5

Ducts Active Solar Sunspace -14.2

Internal Gains

31.5

Total -30

-20

-10

MMBtu/yr

COMPONENT CONSUMPTION SUMMARY Garfield_UDBS

Page 2

Cooling Season

0.1

Ceilings/Roofs Rim/Band Joists Above Grade Walls

-0.1

Foundation Walls

-0.1

Doors

-0.1 0.7

Windows/Skylights Frame Floors Crawl Space/Unht Bsmt -0.2

Slab Floors

-0.1

Infiltration Mechanical Ventilation Ducts Active Solar Sunspace

3.1

Internal Gains -1.2

Whole House Ventilation

2.2

Total -2

-1

MMBtu/yr

2012 IECC OVERALL BUILDING UA COMPLIANCE Date:

May 19, 2012

Rating No.:

Building Name:

Garfield_UDBS

Rating Org.:

Owner's Name:

Phone No.:

Property: Address:

Rater's Name: ,

Rater's No.:

Weather Site:

Pittsburgh, PA

Rating Type:

File Name:

BASELINE_051612.blg

Rating Date:

Builder's Name:

Elements

Insulation Levels 2012 IECC

As Designed

Shell UA Check Ceilings: Above-Grade Walls: Above-Grade Mass Walls: Windows and Doors: Slab Floor: Basement Walls: Overall UA (Design must be equal or lower):

22.4

31.6

138.4

93.1

8.2

7.6

166.2

145.2

6.6

2.5

24.9

18.8

366.6

298.8

0.480

0.280

Window U-Factor Check (Section 402.5) Window U-Factor (Design must be equal or lower):

Building Elements

Type

U-Value

Area

R-30 Batt, Vaulted

0.037

861.0

Wall

R-21, R-10 Cont.**

0.035

648.9

Wall

R-21, R-10 Cont.**

0.035

761.3

Wall

South Facade+Framing**

0.045

754.2

Wall

North Facade+Framing

0.045

170.2

Wall

CMU block

0.076

100.0

Joist

S+N Facade_Level2

0.027

91.4

Joist

South Facede_Level1

0.027

40.7

Joist

E+W Facade_Level 2

0.021

66.1

Joist

E+W Facade_Level1

0.021

52.7

Ceilings Roof Above-Grade Walls

Windows and Doors

Building Elements

Type

U-Value

Area

Window

PELLA WINDOWS2

0.280

115.4

Window

PELLA WINDOWS2

0.280

10.1

Window

PELLA WINDOWS2

0.280

51.6

Window

PELLA WINDOWS2

0.280

60.8

Window

PELLA WINDOWS2

0.280

35.2

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

35.2

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

23.3

Window

PELLA WINDOWS2

0.280

23.3

Door

1-3/8 Wd solid, strm

0.275

23.9

Door

1-3/8 Wd solid, strm

0.275

24.2

On-Grade Perimeter

R-20

0.031

40.0

On-Grade Perimeter

R-20

0.031

40.0

BASEMENT WALLS

0.037

500.5

Slab Floor

Basement Walls Wall

HOME CERTIFIED TO MEET THE PROVISIONS OF THE 2012 INTERNATIONAL ENERGY CONSERVATION CODE This home built at

,, by

exceeds the minimum requirements for the 2012 International Energy Conservation Code

Building Features Ceiling Flat: NA Vaulted Ceiling: U-0.037 Above Grade Walls: U-0.035, U-0.045, U-0.076 Foundation Walls: R-21.1 Exposed Floor: NA

Duct: NA Window: U-Value = 0.280, SHGC = 0.230 Heating: Fuel-fired air distribution, Natural gas, 96.0 AFUE. Cooling: Air conditioner, Electric, 14.5 SEER. Water Heating: Conventional, Natural gas, 0.62 EF, 40.0 Gal.

Signature: Date: May 19, 2012

HOME PERFORMANCE WITH ENERGY STAR ENERGY RATING CERTIFICATE

Estimated Annual Energy Cost

Estimated Annual Energy Consumption MMBtu/yr

1500

1000 857.4 500

831.6 22.0

273.6

20 0

House Type: Single-family detached Cond. Area: 1920 sq. ft. Rating No.: Issue Date: May 19, 2012

Annual Estimates*: Electric(kWh): 7499 Natural gas(MCF): 81 C02 emissions(Tons): 9 Annual Savings**: $1786 * Based on standard operating conditions ** Based on a HERS 130 Index Home

19.0

24.5

1.5

Heating

Total

Service Charge

Photovoltaics

Lights & App

Water Heating

Cooling

Heating

80 58.1 60 40

258.6

Address:

103.1

TITLE Company Address Certified Rater: Certification No: Rating Date:

Total

This Home

Photovoltaics

2000

120 100

Lights & App

2243.1

Cooling

2500

Water Heating

$/yr