An Overview of Ongoing Projects on the Building Envelope

Transcription

1 An Overview of Ongoing Projects on the Building Envelope Presented to: Chicago Roofing Contractors Association Presented by: André Desjarlais Program Manager Building Envelope Systems Research Oak Ridge National Laboratory 19 January 2017 ORNL is managed by UT-Battelle for the US Department of Energy

2 Presentation summary Research projects Web-based tool that estimates energy savings associated with air tightness Cost savings with cool roofs in northern climates Online tool that defines the hygrothermal risk associated with a building envelope selection 2 Building Envelope Systems Research Program

3 Develop an air leakage calculator 3 Building Envelope Systems Research Program

4 Objective Create an easy-to-use online tool using the simulation results of the best-in-class building energy simulation tool EnergyPlus and the whole building airflow simulation tool CONTAM. Online calculator estimates the potential energy and cost savings from improvements in airtightness. Further increase market penetration of air barriers. 4 Building Envelope Systems Research Program

5 Calculations flow Pre-Run Simulations of DOE Commercial Prototype Buildings Max HVAC/ventilation airflow rates Hourly infiltration rates CONTAM EnergyPlus EnergyPlus Envelope airtightness Envelope airtightness Building Details Building details Building details Weather Weather Weather Hourly infiltration rates HVAC/ventilation airflow from CONTAM rates Pre-Run Results Energy use and cost as a function of envelope airtightness City Building type Footprint area User Specified Before / after retrofit airtightness Energy rates Potential Energy and Cost Savings 5 Building Envelope Systems Research Program

6 The tool 6 Building Envelope Systems Research Program

7 Calculator input 7 Building Envelope Systems Research Program

8 The tool: location Analyses the air tightness energy benefits in 52 cities in the US, 5 cities in Canada, and 5 cities in China. Selection of cities based on trying to obtain a reasonable distribution of major metropolitan areas throughout the country; therefore not every state or province is represented. If the specific city you are interested in does not appear on the list, select a city that has similar meteorological conditions (wind, temperature, solar radiation, and rain). This is not always the city geographically closest to your target city. 8 Building Envelope Systems Research Program

9 Locations 9 Building Envelope Systems Research Program

10 The tool: building types Uses the DOE commercial prototype building models. These prototypes were derived from the DOE commercial reference building models. Represent about 80% of new construction. Moreover, these prototypes cover 16 commercial building types in 17 climate locations. The first phase in the development of the calculator covers three prototype building models: standalone retail, medium office, and mid-rise apartment. Models that represent typical commercial buildings in Canada and China are not available in the public domain; therefore, the DOE prototypes are also used in these two countries. 10 Building Envelope Systems Research Program

11 DOE commercial prototype building models (ASHRAE ) used Building Total Floor Area, ft 2 Number of Floors Construction Volume Weights Standalone Retail 24, % Mid-Rise Apartment 33, % Medium Office 53, % High-Rise Apartment 84, % Hospital 241, % Large Hotel 122,132 7 (including basement) 5.0% Small Hotel 43, % Large Office 498, (including basement) 3.3% Small Office 5, % Outpatient Healthcare 40, % Restaurant Fast Food 2, % Restaurant Sit Down 5, % Stripmall 22, % Primary School 73, % Secondary School 210, % Warehouse 49, % 11 Building Envelope Systems Research Program

12 The tool: floor area The air leakage calculations have been performed on a building whose size is defined by the DOE commercial prototype building models. However, the energy and monetary savings associated with improved air tightness was calculated on a per unit floor area basis. To determine the annual savings of your particular building, the actual floor area can be input into this window in lieu of the default floor area from the prototype building. 12 Building Envelope Systems Research Program

13 The tool: air leakage rates Case Air Leakage Rate at 75 Pa (L/s m 2 ) Air Leakage Rate at 75 Pa (CFM/ft 2 ) Source Baseline Emmerich et al (2005) IECC (2015) USACE (2012) DOE (2014) User has the option to either select one of the default values listed below or to input their own air leakage. The tool will interpolate between the baseline air leakage rates 6.2 L/s m 2 (1.22 CFM/ft 2 ) and 0.25 L/s m 2 (0.049 CFM/ft 2 ) at 75 Pa. No extrapolation is allowed. 13 Building Envelope Systems Research Program

14 The tool: energy costs User has the option to either select the default value for energy prices from the following references or to input their own electricity and natural gas prices. Prices for electricity for US cities are maintained by the U.S. Energy Information Administration and 2016 yearto-date average prices for commercial customers were used in the calculations. For natural gas, average 2015 prices for commercial customers were obtained. Energy prices for Canada were taken from the rates used to develop the National Energy Code of Canada for Buildings electricity costs for China were obtained from Chinese sources. 14 Building Envelope Systems Research Program

15 Calculator input 15 Building Envelope Systems Research Program

16 Calculator output 16 Building Envelope Systems Research Program

17 Preliminary results - Chicago HVAC energy cost for a prototype standalone retail building in Chicago 17 Building Envelope Systems Research Program

18 Cost savings with cool roofs in northern cities 18 Building Envelope Systems Research Program

19 Peak demand savings: Cool roofing proof of concept 19 Building Envelope Systems Research Program

20 MW Peak energy demand 30,000 25,000 20,000 15,000 Daytime HVAC Daytime Lighting & Equipment 10,000 5, :00 AM 3:00 PM 6:00 PM Hourly Electrical Demand New England ISO Region, July 22, 2011 Base Demand Source: U. S. Energy Information Administration / ISO New England 20 Building Envelope Systems Research Program

21 Base use vs. peak demand MPH Miles Driven = Base Use (kwh) Top Speed = Peak Demand (kw) 21 Building Envelope Systems Research Program

22 Some utilities with peak demand charges UTILITY STATE UTILITY STATE Alabama Power AL Mississippi County Electric Coop MS SRP AZ Duke Energy NC Pacific Gas & Electric CA Greenville Utilities NC Southern California Electric CA Nebraska Public Power NE San Diego Gas & Electric CA Long Island Power NY Xcel Energy CO National Grid NY Florida Power & Light FL Dayton Power & Light OH Sawnee EMC GA Duke Energy OH Georgia Power GA PECO PA ConEdison IL Duquesne Power PA Duke Energy IN South Caroline Electric & Gas SC NSTAR MA Black Hills Electrical Coop SD WMECO MA Noesis TX Pepco MD ONCOR TX Otter Tail Power MN We Energy WI Source: Google search for websites with peak demand and/or demand charges 22 Building Envelope Systems Research Program

23 Typical commercial electric bill Name/Service Address Acme Enterprises Attn: Accounting Dept. 123 Main Street Hanover, IN Meter Number Elec Reading Date From To Jun 28 Jul 27 For Inquiries Call Duke Energy For Account Services, please contact Betty Smith Days 29 Meter Reading Previous Present Usage 56,780 Account Number Actual kw Base use (56,780 kwh) Duke Energy Rate HSND High Load Factor Sec S/v Other Charges & Credits Demand Charge Energy Charge 56,780 Rider 60 Fuel Adjustment 56,780 Rider 61 Coal Gassification Adj Rider 62 Pollution Control Adj Rider 63 Emission Allowance Rider 66 DSM Ongoing 56,780 Rider 68 Midwest Ind Sys Oper Adj 56,780 Rider 70 Reliability Adjustment 56,780 Rider 71 Clean Coal Adjustment $ $ $ $ $ $ $ $ $ $ , Peak demand (120 kw) $ 4, Total Current Electric Charges $ 4, Source: Duke Energy of Indiana 23 Building Envelope Systems Research Program

24 Base use charges Typical commercial electric bill Name/Service Address Acme Enterprises Attn: Accounting Dept. 123 Main Street Hanover, IN Meter Number Elec Reading Date From To For Inquiries Call Duke Energy For Account Services, please contact Betty Smith Jun 28 Jul 27 Duke Energy Rate HSND High Load Factor Sec S/v Other Charges & Credits Demand Charge Energy Charge 56,780 Rider 60 Fuel Adjustment 56,780 Rider 61 Coal Gassification Adj Rider 62 Pollution Control Adj Rider 63 Emission Allowance Rider 66 DSM Ongoing 56,780 Rider 68 Midwest Ind Sys Oper Adj 56,780 Rider 70 Reliability Adjustment 56,780 Rider 71 Clean Coal Adjustment Days 29 Meter Reading Previous Present $ $ $ $ $ $ $ $ $ $ Base Use (kwh) , Usage 56,780 Account Number Actual kw $ 4, Total base use: $ $ / kwh 44% of Monthly Bill Total Current Electric Charges $ 4, Source: Duke Energy of Indiana 24 Building Envelope Systems Research Program

25 Peak demand charges Typical commercial electric bill Name/Service Address Acme Enterprises Attn: Accounting Dept. 123 Main Street Hanover, IN For Inquiries Call Duke Energy For Account Services, please contact Betty Smith Account Number Total peak demand: Meter Number Elec Reading Date From To Jun 28 Jul 27 Duke Energy Rate HSND High Load Factor Sec S/v Other Charges & Credits Demand Charge Energy Charge 56,780 Rider 60 Fuel Adjustment 56,780 Rider 61 Coal Gassification Adj Rider 62 Pollution Control Adj Rider 63 Emission Allowance Rider 66 DSM Ongoing 56,780 Rider 68 Midwest Ind Sys Oper Adj 56,780 Rider 70 Reliability Adjustment 56,780 Rider 71 Clean Coal Adjustment Days 29 Meter Reading Previous Present $ $ $ $ $ $ $ $ $ $ Usage 56,780 Peak Demand (kw) , Actual kw $ 4, $ $20.10 / kw 56% of Monthly Bill Total Current Electric Charges $ 4, Source: Duke Energy of Indiana 25 Building Envelope Systems Research Program

26 Monthly / Annual Maximum Demand Peak demand: Not just a warm climate issue Peak Cooling Season ( 6 Months +/-) Phoenix Minneapolis Source: Oak Ridge National Laboratory Roof-Related Air Conditioning Demand: Ratio of Monthly to Annual Peak 26 Building Envelope Systems Research Program

27 Peak demand savings: Uniform through all climate zones BTU / 100 Ft Warmest Climate Zones Coldest Climate Zones PHOENIX MINNEAPOLIS Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7-8 Base Use Savings Peak Demand Savings Potential Roof-Related Base Use and Peak Demand Savings Source: RoofPoint Energy and Carbon Calculator 27 Building Envelope Systems Research Program (by North America Climate Zone)

28 Peak demand savings: The calculator Dr. Tom Petrie 28 Building Envelope Systems Research Program

29 Applying the cool roof peak calculator: Model study Composite of model cities in each North American climate zone Representative commercial building 20,000 square foot low-rise structure Heated and cooled with typical HVAC equipment (AC C.O.P. = 2.0, Furnace Efficiency = 0.70) Two construction conditions / insulation levels New insulation meeting 2012 IECC insulation levels Old insulation meeting pre-2012 IECC levels Cool roof solar reflectance (SR) = 0.60 / thermal emittance (TE) = 0.90 Solar reflectance (SR) = 0.60 Thermal emittance (TE) = 0.90 Compared to black roof with SR=0.05 and TE = 0.90 Electrical base use and demand charge identical to sample energy bill Base use: $0.033 / kwh Demand Charge: $20.10 / kw Plus natural gas for heating at $0.70 / Therm 29 Building Envelope Systems Research Program

30 Cool roof model study: New insulation results $2,000 Base Use Savings Peak Demand Savings $1,500 $1,640 $1,340 1,270 $1,000 $500 $0 $1,000 $640 $960 $380 $1,000 $270 $950 $800 $150 $800 $620 $800 $700 $0 -$80 $280 $600 -$320 -$500 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 R20 R20 R20 R25 R25 R30 R35 Estimated Net Energy Savings: Cool Roof Installed over New Insulation (Annual Dollars / 20,000 Square Foot Roof Area) 30 Building Envelope Systems Research Program

31 Cool roof model study: Old insulation results $3,000 $2,500 $3,040 Base Use Savings Peak Demand Savings $2,000 $1,600 $2,250 $1,500 $1,400 $1,870 $1,490 $1,000 $500 $0 $1,440 $850 $1,360 $510 $1,280 $210 $1,220 $1,150 $880 $1,220 $1,200 $1,200 $0 -$50 -$320 -$500 Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 31 Building Envelope Systems Research Program R10 R15 R15 R15 R15 R15 R15 Estimated Net Energy Savings: Cool Roof Installed over Old Insulation (Annual Dollars / 20,000 Square Foot Roof Area)

32 High-performance moisturemanaged envelope systems 32 Building Envelope Systems Research Program

33 Transient hygrothermal processes through the building envelope It get s complicated! During the day.. At night.. 33 Building Envelope Systems Research Program

34 Top challenges in energy efficiency Moisture performance of energy efficient walls Moisture performance of energy efficient attics System/whole-house integration when transition' to more energy effic homes Long-term effectiveness of insulation materials &systems Window installation solutions in walls w/more insulation Details for integration of exterior insulation w/other materials *Total of 14 issues and challenges presented to respondents 34 Building Envelope Systems Research Program

35 Building Scientist: Fascinating! I wonder which hygrothermal transport mechanism led to this Stachybotrys colonization?! 35 Building Envelope Systems Research Program 35

36 What building designers are thinking!#$!?! 36 Building Envelope Systems Research Program

37 Building materials are changing 37 Building Envelope Systems Research Program

38 Buildings are getting tighter 38 Building Envelope Systems Research Program

39 Energy code requirements are changing 50% 40% 30% 20% 10% 0% -10% -20% -30% -40% IECC Code /2015? 39 Building Envelope Systems Research Program

40 Technology & expectations are changing Anyone who looks can find defects

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42 Maybe we need Expert advice? Wouldn t it be great if there was an App with an expert inside?! 42 Building Envelope Systems Research Program

43 Coming soon: Building Science Advisor 43 Building Envelope Systems Research Program

44 Building Science Advisor (BSA) ORNL and the Building America team are developing an online decision-making tool to mitigate market uncertainty regarding the durability of high-performing building envelope systems Subject matter experts input moisturedurable design guidelines Guidelines are also based on field data and simulations Simulations allow probabilistic wall assembly evaluations by considering all possible parameter variations BSA analyzes builders proposed design to yield most robust assembly Moisture Durability 44 Building Envelope Systems Research Program

45 Welcome to Building America Building Science Advisor (BSA) Building America BSA is a website that provides expert advice on building envelope system performance from industry s best researchers and building scientists. This knowledge tool promotes better-informed decisions regarding energy-efficient and moisture-durable building envelope solutions. BSA communicates uncertainty associated with moisture durability in a simplified manner. Start BSA About BSA 45 Building Envelope Systems Research Program

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48 What do you want to do for the next step? View recommended walls This option provides you with wall assemblies that are moisture durable under the chosen climate and materials selections. Go to advanced analysis Specify all materials of the wall assembly for moisture durability assessment of the chosen wall design. This option will also provide guidance for best performance if needed. 48 Building Envelope Systems Research Program

49 Summary of your wall options Climate Zone Exterior Cladding Continuous Insulation Type Wall Structure Cavity Insulation Cavity Insulation Type Houston, TX Brick None 2 x 4 16" o.c. R13 Fiberglass Batt Recommended wall systems Cladding 01 Brick 02 Brick 03 Brick 04 Brick 05 Brick Water/Air Air gap Sheathing Structure barrier Yes, 2x4 House wrap OSB vented 16 o.c. Yes, 2x4 House wrap OSB vented 16 o.c. Yes, 2x4 House wrap OSB vented 16 o.c. Yes, vented Building Paper OSB 2x4 16 o.c. Yes, vented House wrap Plywood 2x4 16 o.c. Cavity insulation Fiberglass Batt Fiberglass Batt Cellulose Loose Fill Fiberglass Batt Fiberglass Batt Insulation Vapor retarder Interior finish Air tightness None None Latex paint 5 ACH50 None None Latex paint 3 ACH50 None None Latex paint 5 ACH50 None None Latex paint 5 ACH50 None Kraft Paper Latex paint 5 ACH50 49 Building Envelope Systems Research Program

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51 The wall has absorptive cladding with no air gap. To ensure moisture durability add at least a 2" ventilation cavity between absorptive cladding and sheathing. Also consider using low perm sheathing or insulated sheathing. 51 Building Envelope Systems Research Program

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53 The wall has absorptive cladding. To ensure moisture durability add at least a 2" ventilation cavity between absorptive cladding and sheathing. Also consider using low perm sheathing or insulated sheathing. 53 Building Envelope Systems Research Program

54 Discussion André Desjarlais Visit our website: Follow us on 54 Building Envelope Systems Research Program