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C A L I F O R N I A E N E R G Y C O M M I S S I O N Cool Roofs in Californias Title 24 2005 Building Energy Efficiency Code Elaine Hebert, Energy Efficiency.

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Presentation on theme: "C A L I F O R N I A E N E R G Y C O M M I S S I O N Cool Roofs in Californias Title 24 2005 Building Energy Efficiency Code Elaine Hebert, Energy Efficiency."— Presentation transcript:

1 C A L I F O R N I A E N E R G Y C O M M I S S I O N Cool Roofs in Californias Title 24 2005 Building Energy Efficiency Code Elaine Hebert, Energy Efficiency Specialist California Energy Commission, Sacramento

2 C A L I F O R N I A E N E R G Y C O M M I S S I O N 2 What We Will Cover Today How Cool Is a Cool Roof? How Californias Title 24 (Part 6 is Energy Code) Works Title 24 Cool Roof regulations Contact Information/Resources

3 C A L I F O R N I A E N E R G Y C O M M I S S I O N 3 How Cool is a Cool Roof? (1) Sacramento, CA July 12, 2000 89 ºF, about noon, with local delta breeze EPDM single-ply 173 °F BUR topped with capsheet 158 °F BUR topped with aggregate 159 °F Courtesy Dan Varvais, Applied Polymer Systems

4 C A L I F O R N I A E N E R G Y C O M M I S S I O N 4 How Cool is a Cool Roof? (2) Sacramento, CA July 12, 2000 89 ºF noon delta breeze Cool coating over BUR 108 °F Cool single-ply 121 °F Courtesy Dan Varvais, Applied Polymer Systems

5 C A L I F O R N I A E N E R G Y C O M M I S S I O N 5 Cool Roofs and Energy Cooler roof surfaces can save 15% of electricity needed to cool a building This is important because we still have an electricity crisis. Not quite enough supply to meet demand and have mandated reserve Transmission lines – aging, inadequate capacity

6 C A L I F O R N I A E N E R G Y C O M M I S S I O N 6 Adequate electricity supplies help prevent blackouts in California (this blackout in the Midwest equaled about $6B in damage)

7 C A L I F O R N I A E N E R G Y C O M M I S S I O N 7 Through Energy Efficiency Measures, California Keeps Per Person Use of Electricity Steady While Rest of US Goes Up

8 C A L I F O R N I A E N E R G Y C O M M I S S I O N 8 Title 24, Part 6, Californias Energy Code: How It Works (1) Sets an energy budget for residential and nonresidential buildings –New buildings and additions/alterations (alterations can include re-roofing) –Budget is in kBtu/square foot/year –Budget varies by climate zone 16 climate zones in California

9 C A L I F O R N I A E N E R G Y C O M M I S S I O N 9 Californias 16 Climate Zones www.energy.ca.gov/maps/ climate_zone_map.html Climate Zone 1, coastal, foggy most of year Climate Zone 16 – mountains, snows in winter, less than 80°F in summer Many inland climate zones – mild winters, hot dry summers (population increasing most, air conditioning needs increasing)

10 C A L I F O R N I A E N E R G Y C O M M I S S I O N 10 Title 24, Part 6: How It Works (2) Regulates the Following: Efficiency of Lighting Windows, doors, skylights Water heating systems Space heating and cooling systems Nonresidential Roofs (as of Oct. 2005) Insulation levels in walls, floors, and ceilings/attics/roofs Tightness of air ducts Allowed square footage of windows, doors, and skylights And more...

11 C A L I F O R N I A E N E R G Y C O M M I S S I O N 11 Title 24, Part 6: How It Works (3) How to Meet the Energy Budget Design the building or addition/alteration with appropriate energy efficiency features Submit documentation to bldg. dept. with permit application Construct the building/addition/alteration with those features Building Inspectors are responsible for confirming that the installed energy features match the features in the paperwork you submitted

12 C A L I F O R N I A E N E R G Y C O M M I S S I O N 12 Meeting the Energy Budget: Design and build a building … Prescriptive Measures OR Performance Method AND Mandatory Measures (for energy efficiency) …using items from previous slide that comprise: Provide documentation to bldg dept with bldg permit application

13 C A L I F O R N I A E N E R G Y C O M M I S S I O N 13 Prescriptive means - - Title 24 provides a list of the minimum efficiencies of some energy features. The list is like a prescription for how to construct a building to meet the energy budget. Follow the prescription exactly to construct the building and it automatically complies with Title 24 – no calculations or computer needed

14 C A L I F O R N I A E N E R G Y C O M M I S S I O N 14 Performance means - - Model how the entire building will perform energy-wise using approved computer program – Allows flexibility - can trade off among energy efficiency measures – Energy budget for your (modeled) building is established by a similar modeled building (standard building) having all mandatory and prescriptive measures Buy software yourself, or hire a Title 24 consultant - see www.cabec.org for trained Calif. energy consultants; most have the software

15 C A L I F O R N I A E N E R G Y C O M M I S S I O N 15 WHICH MEANS if you use the prescriptive compliance method, you must install a cool roof (or do an allowed tradeoff among building envelope components only) OR if you use performance compliance, you can install a cool roof or not, but a cool roof helps set the energy budget for your proposed project Cool Roofs Are a Prescriptive Measure for Nonresidential Buildings (Cool roofs are NOT mandatory)

16 C A L I F O R N I A E N E R G Y C O M M I S S I O N 16 What is a (Prescriptive) Cool Roof under Californias Title 24 Energy Standards? Roof material must Be rated through Cool Roof Rating Council (Title 24, Part 1, §10-113) Be properly labeled (Title 24, Part 1, §10-113) Have reflectance 0.70 and emittance 0.75 (or if emittance is lower, need higher reflectance) [Part 6, §118(i)1 and 2] For coatings liquid-applied in the field, meet performance requirements [Part 6, §118(i)3 & Table 118-C]

17 C A L I F O R N I A E N E R G Y C O M M I S S I O N 17 What Are Reflectance and Emittance? Reflectance – straightforward – suns energy (heat) bouncing off roof surface Emittance – not ALL energy bounces off; some is absorbed. Absorbed energy is given off – emitted – at different rates by different materials. Emittance is a measure of how quickly or efficiently the absorbed energy is given off. –Important because slowly emitted heat has time to penetrate downward into the building - - undesirable in most Calif. climate zones; increases air conditioning

18 C A L I F O R N I A E N E R G Y C O M M I S S I O N 18 Title 24 (Prescriptive) Cool Roofs Apply to - - Conditioned space (heated or cooled) Low slopes ( 2:12) Nonresidential buildings only, Occupancy Groups A, B, E, F, H, M, S, and U (next slide) EXCLUDES –Occupancy I- hospitals, prisons, mental institutions, other institutions –hotels/motels –refrigerated warehouses

19 C A L I F O R N I A E N E R G Y C O M M I S S I O N 19 Occupancy Groups (from CBC/UBC) A = Assembly – theaters, churches, restaurants, etc B = Businesses – office buildings, colleges/univers. E = Educational facilities (12 th grade & under) F = Factories, low and moderate hazard H = High hazard facilities M = Mercantile; sale of merchandise S = Storage, low and moderate hazard U = Utility – garages, towers, agric. buildings, etc Expanded list on page 8 of www.energy.ca.gov/2005publications/CEC-400-2005-053/CEC- 400-2005-053.PDF

20 C A L I F O R N I A E N E R G Y C O M M I S S I O N 20 Cool Roofs Are Only Optional (NOT prescriptive, NOT mandatory) for - - Hotels and motels ALL residential buildings (including houses and high-rise apartments/condos) Unconditioned buildings Refrigerated warehouses, other spaces held under 55°F, and spaces held over 90°F Buildings cooled by evaporative coolers/swamp coolers Roofs with slopes over 2:12

21 C A L I F O R N I A E N E R G Y C O M M I S S I O N 21 Take Note Qualifying historic buildings (per Title 24, Part 8) are exempted from Title 24, Part 6 energy standards.

22 C A L I F O R N I A E N E R G Y C O M M I S S I O N 22 Cool Roofs 2005 - Nonresidential Re-roofing Still prescriptive If >50% or >2,000 sf of low-sloped roof, whichever is less, is being replaced, recovered, or recoated, cool roof requirements kick in [§ 149(b)1B] –Install a cool roof OR –Install a noncool roof plus roof insulation This is how a garden roof or BIPV* roof can be installed when re-roofing Coming soon: easy calculator for how much insulation * BIPV = Building-integrated photovoltaics (solar electric pv modules become the roof)

23 C A L I F O R N I A E N E R G Y C O M M I S S I O N 23 Reroofing Existing Unconditioned Warehouse Containing Conditioned Office Space - Cool Roof?? Consider two cases: 1. Conditioned spaces ceiling is lower than warehouse roof

24 C A L I F O R N I A E N E R G Y C O M M I S S I O N 24 Unconditioned warehouse containing conditioned space (see the air ducts!) Energy Commission considers this building unconditioned, so no cool roof rules are triggered

25 C A L I F O R N I A E N E R G Y C O M M I S S I O N 25 Case 1 – Reroofing unconditioned warehouse containing conditioned office – walls of office do not reach warehouse roof No cool roof requirements are triggered!

26 C A L I F O R N I A E N E R G Y C O M M I S S I O N 26 Case 2 – Reroofing unconditioned warehouse containing conditioned office – walls of office reach up to warehouse roof (Sorry, no photo yet) Cool Roof requirements apply OVER THE CONDITIONED SPACE(S) ONLY not over the entire warehouse roof

27 C A L I F O R N I A E N E R G Y C O M M I S S I O N 27 TAKE NOTE! Energy Star is a different program (Federal not state) –An Energy Star roof does not automatically qualify as a cool roof in California Cool Roof Rating Councils rated product directory has over 650 roof materials – some comply with Title 24 and some dont

28 C A L I F O R N I A E N E R G Y C O M M I S S I O N 28 Excerpt from CRRC Rated Product Directory (www.coolroofs.org)

29 C A L I F O R N I A E N E R G Y C O M M I S S I O N 29 NOTE: Partly Cool Roofs Roofing materials not meeting the FULL 0.70 reflectance/0.75 emittance Title 24 levels can get partial energy credit for some building types when using computer performance modeling and overall envelope prescriptive compliance Materials NOT rated through CRRC are assigned a default value in Title 24 for reflectance – it is LOW – so you must meet the energy budget using other energy- efficient features

30 C A L I F O R N I A E N E R G Y C O M M I S S I O N 30 Help Is on the Way Energy Commission has started a collaborative for training on cool roof regulations for –Roofing Contractors –Building departments –And eventually, architects/specifiers, building owners, consultants

31 C A L I F O R N I A E N E R G Y C O M M I S S I O N 31 Resources Title 24 Website – www.energy.ca.gov/title24 (Title 24 Energy Standards and support documents) Title 24 Energy Hotline - 1-800-772-3300 (within CA), 916-654-5106 (outside CA), title24@energy.state.ca.us Title 24 Office – 916/654-4064 –Elaine Hebert – 916/654-4800, ehebert@energy.state.ca.us Approved energy compliance software: –MicroPas (residential), www.micropas.com –EnergyPro (res & nonres), www.energysoft.com

32 C A L I F O R N I A E N E R G Y C O M M I S S I O N 32 Resources Cool Roof Rating Council - www.coolroofs.org, (866) 465-2523 CABEC (Calif. Assoc. of Building Energy Consultants) - www.cabec.org, (866) 360-4002 Title 24 Energy Information Videos (free) - www.energyvideos.com Coming soon: cool roof website, insulation calculator, shortened form for cool roof reroofing permits, training materials for roofing contractors & other parties, 2008 Standards

33 C A L I F O R N I A E N E R G Y C O M M I S S I O N 33 Thank you!


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