PROMOTING FENESTRATION ENERGY EFFICIENCY: ROLE OF RATING AND CERTIFICATION

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PROMOTING FENESTRATION ENERGY EFFICIENCY ROLE
OF RATING AND CERTIFICATION

• John Hogan, NFRC, A.I.A., P.E.
• Senior Code Development Analyst
• Seattle Department of Design, Construction and
  Land Use
• 700 Fifth Avenue, Suite 2000
• Seattle, Washington 98104
• New Delhi, India, 22 November 2002
• Bangalore, India, 25 November 2002

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OUTLINE

• Overview of energy consumption and energy
  efficiency- importance of fenestration
  (windows, doors, skylights)
• Advances in fenestration technology
• Market problems for advanced fenestration
  technologies
• Supporting energy efficient fenestration
  technologies- NFRC (National Fenestration
  Rating Council) program- 1992 U.S. National
  Energy Policy Act (EPAct)
• NFRC in U.S. model codes for energy IECC,
  ASHRAE 90.1
• U.S. Energy Star Program U-factor SHGC
  requirements
• Conclusions

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ENERGY CONSUMPTION EFFICIENCY

• India is the 6th largest energy consuming nation

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IMPORTANCE OF FENESTRATION ENERGY EFFICIENCY

• Energy efficient fenestration (windows, doors,
  skylights) reduces energy use in buildings
  cooling, lighting, heating
• Benefits to occupants greater thermal comfort,
  less glare
• Benefits to tenants reduced energy bills (due
  to lower energy consumption and lower peak
  demand), greater productivity
• Benefits to building owner reduced size (and
  cost) of air conditioning equipment offsets cost
  of better fenestration, space is more desirable
  to lease
• Benefits to utility reduced power plant
  construction costs
• Benefits to society reduced pollution

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ADVANCES IN FENESTRATION TECHNOLOGY

• Low-emissivity coatings - pyrolytic vs.
  sputter, placed on glass or on suspended films
• Spectrally selective daylighting with less
  solar heat gain, (look for visible transmittance
  gt 1.2 x SHGC)
• Inert gas fills typically 90 argon, rarely
  krypton
• Low-conductance spacers reduces condensation
• Advanced frames - curtainwalls w/exterior
  metal minimized, metal cap w/isolation - metal
  outside/wood inside, new frame materials

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MARKET PROBLEMS FOR ADVANCED FENESTRATION
TECHNOLOGIES

• Fenestration performance claim not based on
  overall product- often based on center-of-glass
  only- ignores the effects of edge-of-glass and
  frame
• Progressive manufacturers need a method to fairly
  compete and take credit for all the nuances of
  their innovations
• Testing every product is expensive
• Fenestration not labeled in the field for the
  inspectors
• Overstated energy performance (results in
  decreased confidence in energy efficiency when
  actual energy use is higher)

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SUPPORTING ENERGY EFFICIENT FENESTRATION
TECHNOLOGIESBenefits of the NFRC Program

• Provides a means for manufacturers to take credit
  for nuances and refinements to product design
  (using latest research international stds such
  as ISO 15099)
• Involvement of independent laboratories and IAs
  provides architects, engineers, designers,
  contractors, consumers, building officials, and
  utility representatives with greater confidence
  that the information is unbiased
• Focus on simulation (rather than testing) means
  that - initial product development is less
  expensive, and- obtaining ratings is less
  expensive (than testing all options)

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BENEFITS OF NFRC PROGRAM (cont.)

• By using simulation as the basis but coupling it
  with a single validation test, there is an
  automatic check on accuracy (testing alone
  allows manufacturers to perform several tests and
  then use the best one for product claims and code
  compliance)
• The certification process indicates that the
  manufacturer is consistently producing the
  product that was rated (it is not acceptable for
  manufacturers to make an exceptionally high
  quality sample and obtain a good rating in a
  test)
• Readily visible temporary label that can be used
  by the building inspector to quickly verify
  Energy Code compliance
• Permanent label that enables future access to
  energy rating information

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NFRC Temporary Label (ratings in I-P)

• Website for further information www.nfrc.org

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NFRC Temporary Label (I-P SI)
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U.S. ENERGY POLICY ACT (EPAct)

• National fenestration energy rating system1992
  EPAct requires development of a national
  fenestration energy rating system, specifies NFRC
  as preferred developer
• Baselines for State Energy Codes- International
  Energy Conservation Code (IECC) as the baseline
  for low-rise residential buildings (formerly
  the Model Energy Code) - ASHRAE/IESNA Standard
  90.1 as the baseline for high-rise residential
  buildings and all nonresidential buildings
  (developed jointly by the American Society of
  Heating, Refrigerating, and Air-conditioning
  Engineers and the Illuminating Engineering
  Society of North America)

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FENESTRATION RATINGS IECC

• 2000 International Energy Conservation Code
  (Section102.3) U-values of fenestration
  products (windows, doors, and skylights) shall be
  determined in accordance with NFRC 100 by an
  accredited, independent laboratory, and labeled
  and certified by the manufacturer. The solar
  heat gain coefficient (SHGC) of glazed
  fenestration products (windows, glazed doors, and
  skylights) shall be determined in accordance with
  NFRC 200 by an accredited, independent
  laboratory, and labeled and certified by the
  manufacturer.
• Applies to all fenestration products in all
  building types

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FENESTRATION RATINGS Std. 90.1

• ASHRAE/IESNA Standard 90.1-2001 (Sections 5.2.2
  and 5.2.3) U-factors, SHGC, visible
  transmittance, air leakage to be - determined
  in accordance with NFRC 100, 200, and 400 and -
  determined by a laboratory accredited by a
  nationally recognized accreditation
  organization,such as the National Fenestration
  Rating Council, and shall be labeled and
  certified by the manufacturer
• Applies to all buildings except low-rise
  residential buildings

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CLIMATE DATA

• Climate variables used in the IECC and ASHRAE
  90.1 - HDD18 Annual Heating Degree Days,
  base 18 degrees C- CDD10 Annual Cooling Degree
  Days, base 10 degrees C
• Indian climate data (from ASHRAE Standard
  90.1)- New Delhi 267 HDD18, 5589 CDD10,
  Table B-2 (480 HDD65, 10060
  CDD50)- Bangalore 1 HDD18, 5227 CDD10,
  Table B-2 (2 HDD65, 9409
  CDD50)similar to- Miami 111 HDD18, 5263
  CDD10, Table B-2 Florida, USA
  (200 HDD65, 9474 CDD50)

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ASHRAE Standard 90.1 Example Table

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IECC 90.1 FENESTRATION CRITERIA New Delhi and
Bangalore

• Residential buildings lt 3 storieswith
  fenestration area lt 30 of wall area (2000
  IECC) U-factor 5.1 maximum (double-glazing,
  any frame type) SHGC 0.40 maximum
• Residential buildings gt 3 stories all public
  buildingswith fenestration area lt 40 of wall
  area (90.1-2001) SHGC 0.25 maximum (0.44
  for north-facing) Visible transmittance (VT) gt
  1.00 x SHGC
• Websites for further informationIECC
  www.intlcodes.org ASHRAE 90.1 www.ashrae.org

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VOLUNTARY PROGRAMSU.S. ENERGY STAR

• Goal- to help consumers quickly and easily
  identify products that save energy
• U.S. Department of Energy (DOE) programs-
  refrigerators, dishwashers, clothes washers,
  room air conditioners, and fenestration
  products
• U.S. Environmental Protection Agency (EPA)
  programs- home electronics, residential heating
  equipment, lighting, and whole building programs

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ENERGY STAR - FENESTRATION

• Fenestration products included- windows-
  doors- skylights
• U.S. divided into three climate regions-
  Northern (where space heating is a dominant
  concern)- Central (where both heating and
  cooling are significant)- Southern (where space
  cooling is a dominant concern)

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ENERGY STAR - CLIMATE MAP
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ENERGY STAR - CRITERIA

• Northern - windows doors U-2.0 or less (no
  SHGC requirements)- skylights U-2.5 or less
  (no SHGC requirements)
• Central - windows doors U-2.3 or less, SHGC
  of 0.55 or less- skylights U-2.5 or less, SHGC
  of 0.55 or less
• Southern - windows doors U-4.3 or less, SHGC
  of 0.40 or less - skylights U-4.3 or less,
  SHGC of 0.40 or less
• Website for further information-
  http//www.energystar.gov

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CONCLUSIONS

• A consistent rating and certification system is
  essential to promote widespread use of energy
  efficient fenestration products
• The U.S. National Fenestration Rating Council
  (NFRC) has established a rating, certification,
  and labeling system - addresses the complexity
  of current fenestration products - provides a
  means to verify product performance
• U.S. national model codes based on NFRC
  fenestration ratings - 2000 International Energy
  Conservation Code (IECC) - ASHRAE/IESNA Standard
  90.1-2001
• Voluntary Energy Star requirements also use the
  NFRC program
• Result is greater market share of energy
  efficient fenestration