The Latest from the Keep Aluminum Windows Campaign. Thomas D. Culp, Ph.D. Aluminum Extruders Council

Transcription

1 The Latest from the Keep Aluminum Windows Campaign Thomas D. Culp, Ph.D. Aluminum Extruders Council

2 Topics Introduction to KAW Benefits of Aluminum Fenestration Energy Codes Code Organizations & Basics Problems with the Codes KAW Actions Other Issues

3 The Keep Aluminum Windows Campaign Formed by the Aluminum Extruders Council (AEC) in 2002 to serve the interests of the aluminum fenestration industry. Advocate for aluminum in all aspects of the building and construction industry: residential and commercial. KAW promotes advancements in overall energy performance in conjunction with other key requirements, such as structural performance and durability. Very active with energy codes (IRC, IECC, ASHRAE) and fenestration rating programs (Energy Star, NFRC, AAMA).

4 KAW Participation Recently expanded to include new Manufacturer and Technical Advisory Subcommittees. Participation open to any company involved with or supportive of aluminum fenestration. Previously, KAW participation was limited to AEC extruder or supplier members. Increased opportunity to involve manufacturers and others whom our advocacy is directly benefiting.

5 Previous KAW Victories Energy Star Windows ( ) Convinced DOE to adopt performance-based criteria in the south and south central zones. IECC Commercial Energy Code ( ) Passed key code proposal for 2006 IECC with revised U-factor requirements that accommodate structural products while promoting energy efficiency. ASHRAE 90.1 ( ) Convinced ASHRAE to adopt revised fenestration criteria in line with the corrected IECC requirements, accommodating structural products for commercial buildings.

6 Benefits of Aluminum Fenestration Superior structural performance Dominant material in commercial architectural windows, storefront, t, curtainwall, high wind load applications Superior durability Longer design lifetime Long term energy performance Superior manufacturing Design flexibility High production rates and yields Cost effective Green, safe material fully recyclable low energy to reprocess superior fire and smoke performance energy efficient with advanced thermal-barrier frames

7 Energy Codes Code Basics Problems with the Codes KAW Actions

8 Who makes the code? U.S. Code Organizations: International Code Council (ICC) National Fire Protection Association (NFPA) American Society of Heating, Refrigeration, and Air-conditioning Engineers (ASHRAE) Technically a standards organization, but often used as commercial energy code. These are private organizations, not part of federal government.

9 National vs. Regional Codes These organizations develop national model codes. Actual legal authority is at the local level. States, Counties, Cities The national model code has no power until adopted by the local jurisdiction. Federal government has no direct authority, but Can create and influence proposed code changes. Can force states to evaluate certain codes. Sets code requirements for government buildings. As a result, adoption and enforcement of codes vary across the country, but the model code is still the major driving force.

10 U.S. Residential Energy Codes Dominated by two ICC codes: IRC - International Residential Code IECC - International Energy Conservation Code Approximately 70% of states have adopted IRC / IECC or equiv. Several western states are home rule and leave code adoption to individual town or county. ASHRAE 90.2 also pushed by NFPA, but rarely used.

11 U.S. Commercial Energy Codes Dominated by two codes / standards: ASHRAE Energy Standard for Buildings Except Low-Rise Residential Buildings IECC - International Energy Conservation Code ASHRAE 90.1 is dominant, but IECC is growing. IECC actually gives builder the option to use either ASHRAE 90.1 or simplified prescriptive requirements. Some variations at local level.

12 Prescriptive vs. Performance Requirements Prescriptive requirements Specify minimum criteria for each individual property or component in the design. Simple, but discriminates against products which do not exactly fit the design (regardless of performance). These often drive product design because of simplicity. Performance-based requirements Specify minimum level for overall performance. Only achieving the performance level matters, not how you get there. More complex to calculate overall performance, but does not discriminate against individual components or materials. In energy codes, use UA trade-off to show equivalence of overall envelope, or whole building calculation of annual energy cost.

13 2006 IRC / IECC Prescriptive Requirements Residential Fenestration Thermally isolated sunroom: Zone 8, 7, 6, 5, 4 Marine 4 except Marine 3 Marine 3 except Marine 2 1 U vertical U skylight Zones 4-8: 4 max U = 0.50 for vertical, 0.75 for skylight Unconditioned or low-energy (< 1 W/ft 2 ) sunroom: No requirements SHGC NR NR NR

14 Problems with the Energy Codes 1. Focus is still on just U-factor, U not overall energy performance.

15 1. Focus is still on just U-factor, U not overall energy performance. Prescriptive U and SHGC requirements are simple, but have no flexibility. It is inaccurate to look at U, SHGC, and AL separately. Total energy performance is determined by the combination of these factors. Prescriptive requirements do not allow for trade-offs between U, SHGC, AL even if have equivalent energy performance.

16 1. Focus is still on just U-factor, U not overall energy performance. Products may greatly surpass one requirement (SHGC or AL) and only barely miss the other (U), but prescriptive requirements give no credit. Discriminate against non-standard products. Having alternative performance methods for building is not enough. Even if building performance methods are allowed, prescriptive requirements drive product design for individual components. Use of performance methods are often too expensive for smaller commercial buildings or individual homes. Some code officials don t t understand performance methods. Need to support performance-based trade-offs in the codes and Energy Star.

17 1. Focus is still on just U-factor, U not overall energy performance. KAW Actions: Energy Star Windows Convinced DOE to adopt equivalent energy performance- based criteria in the south and south central zones. Allow higher U if compensate with lower SHGC. More flexibility for non-thermally broken aluminum products in Southern zone. Although still difficult, more flexibility for thermally broken aluminum frames in South Central zone. Allow more aluminum residential windows and doors to qualify for Energy Star labeling. Important precedent that all future changes must also be performance-based.

18 1. Focus is still on just U-factor, U not overall energy performance. KAW Actions: Energy Star Windows Equivalent Energy Performance Amendment for Windows and Doors:

19 1. Focus is still on just U-factor, U not overall energy performance. KAW Actions: Northern trade-off code proposal Proposal to IECC / IRC for residential fenestration in northern cold climates. Allow higher U-factor U if balance with higher SHGC. Equivalent energy performance as current prescriptive criteria, based on LBNL report for Energy Star. Approved by IRC at preliminary hearings. Disapproved by IECC. Final decision at final hearings in May. ALTERNATIVE FENESTRATION U-FACTOR AND SHGC REQUIREMENTS IN ZONES 6 THROUGH 8 GLAZED FENESTRATION SHGC MAXIMUM FENESTRATION U-FACTOR < SHGC < SHGC < SHGC < SHGC < SHGC

20 Problems with the Energy Codes 2. Trade-off Limits or Hard Caps create artificial constraints.

21 2. Trade-off Limits or Hard Caps Hard caps set absolute limits on window properties which may never be exceeded, even when trade-off methods are used to show the building has equivalent total energy use. Original proposal by DOE: U-factor may never exceed 0.55 in zones Intent was to prevent builders from using cheap, single-pane windows in the north, by trading off improved insulation or HVAC. Unnecessary, because market has already eliminated single-pane windows in the north.

22 2. Trade-off Limits or Hard Caps Certain parties are trying to impose more restrictive caps to favor their products. Most restrictive caps in 2004 IECC Supplement and 2006 New York Residential Code: U-factor may never exceed 0.40 in zones SHGC may never exceed 0.50 in zones Illogically, would require a lower U-factor than the prescriptive requirements for skylights and thermally-isolated sunrooms when using trade-offs!

23 2. Trade-off Limits or Hard Caps Hard caps save no energy! The entire point of trade-off methods is that the building has equivalent overall energy efficiency. Caps place artificial constraints and limit flexibility with regards to choice of fenestration products. Discriminate against specialized products: Glass block Garden windows Metal hurricane-impact impact windows Metal sunrooms

24 2. Trade-off Limits or Hard Caps KAW Actions: Helped modify 2006 IECC to provide more flexibility in zones for metal hurricane products. Conflict with U-factor may never exceed 0.40 in zones thermally-isolated U-factor may never exceed 0.48 in zones sunroom SHGC may never exceed 0.50 in zones requirements still Fixed skylight problem (limit U < 0.75 in zones 4-8) 4 exists! Helped convince 2006 IRC to stay with original DOE proposal. U-factor may never exceed 0.55 in zones Fixed skylight problem (limit U < 0.75 in zones 6-8) 6 No trade-off limits in zones Helped convince the IRC committee to completely remove trade-off limits in 2007 Supplement.

25 Problems with the Energy Codes 3. Energy Codes are kept separate from Structural Codes.

26 3. Energy and Structural Performance The interrelationship between energy and structural performance is largely ignored. Codes often conflict, such as in the hurricane zone which extends from zone 1 to zone 5. Wind load and impact requirements often require aluminum framing or heavy reinforcement, but continuing to reduce U-factor U restricts structural products. If not resolved, problem has to be dealt with by either putting exception in local code or using performance alternatives.

27 3. Energy and Structural Performance KAW Actions: 2006 IECC Commercial Energy Code Passed critical code proposal with revised U-factor U requirements that accommodate structural products while promoting energy efficiency. Previous requirements in 2004 Supplement were highly flawed: U-factors would not have allowed aluminum operable windows or doors in northern half of U.S. Favored nonmetal products, while ignoring structural requirements. (vinyl windows in a highrise?!? vinyl curtainwall?!?) AEC, AAMA, NBI developed compromise with revised U-factor U requirements that accommodate structural products. Clearer metal and nonmetal product categories. Will require increased thermal barrier, low-e. Will require double glazing except in Miami, Hawaii.

28 3. Energy and Structural Performance 2006 IECC Commercial Fenestration Requirements If place a sunroom on a highrise building (e.g. hotel, penthouse), use these U-factors, depending on frame type. Also have to meet SHGC requirements.

29 3. Energy and Structural Performance KAW Actions: ASHRAE 90.1 ASHRAE 90.1 is still the dominant commercial energy code. Recent update to fenestration criteria (last update was 1999). Initial proposal was highly flawed, and did not consider structural requirements: U-factor of in zones 1-41 U-factor of in zones 5-85 Triple-glazing down to Indianapolis, and problems for operable products all the way south! Favored nonmetal windows in all zones, regardless of structural or durability requirements. Successfully convinced subcommittee to adopt similar categories and values as our IECC proposal. Stringent but realistic for structural products. They did tweak the numbers in zones (N. Minnesota, Alaska).

30 3. Energy and Structural Performance KAW Actions: ASHRAE 90.1 Changes shown on IECC table for simplicity: Just completed public review. Will become an addendum to 2007 edition. Available for use, but not of part of the published standard until Jan 2009 mid-cycle supplement, and July 2010 full standard for nonresid NR for resid, semiheated

31 Problems with the Energy Codes 4. Long term durability of energy performance is ignored.

32 4. Long Term Energy Performance What matters is energy performance over the lifetime of the building not just when it is installed. U, SHGC, and Air Leakage can change over time as different types of products degrade. Air infiltration can increase dramatically if frame deforms over time from thermal and pressure cycling. Aluminum has superior durability over vinyl, wood, and fiberglass, but amount of change is debated. NFRC has tried to examine this issue (unsuccessfully) for the last 14 years.

33 Other Issues Fenestration Energy Rating Programs New Green Standards

34 Fenestration Energy Rating Programs NFRC 100 and 200 Current program works well for factory-built residential products. Cumbersome and expensive for site-built commercial products Not suited to wide product variation and involvement of different parties (frame manufacturer, glass fabricator, glazing contractor, etc.) Largely ignored for curtainwall, storefront, etc. Does it work for site-built sunrooms?

35 Fenestration Energy Rating Programs AAMA 507 Developed especially for rating commercial products. Based on data from NFRC simulations and tests, but more flexible for determining whole-product U and SHGC as a function of center-of of-glass values and actual size. Easier and less expensive for industry, and will also increase enforcement good for everyone. AEC, GANA, Conner submitted joint proposal to allow AAMA 507 as alternative to NFRC sitebuilt ratings for fenestration in commercial buildings. Not approved at preliminary hearings, but modified proposal will be voted on at final hearings.

36 Fenestration Energy Rating Programs NFRC Component-Based Modeling Approach (CMA) New rating program under development. Component approach similar to AAMA 507, where individual components (frame, glass, and spacer) are combined into final whole-product rating. New rating procedure will be big improvement over site- built procedure, if it is simple and cost-effective. Potentially better than AAMA 507, but costs and final outcome are still very uncertain. Initial focus is commercial fenestration, but could be important to sunrooms (especially site-built).

37 New Green Standards National Green Building Standard New standard for high-performance green homes. Joint collaboration between NAHB and ICC. Could compete with LEED for Homes program from USGBC. ASHRAE 189 New standard for high-performance sustainable commercial buildings (not including low-rise residential). Joint collaboration between ASHRAE, USGBC, and IESNA. Written as a standard, not a design guide. Initially voluntary, but could likely replace LEED in mandatory codes (e.g. government buildings). Both will be important to monitor. For both, first public review draft expected by July.

38 To find out more about KAW, contact: Aluminum Extruders Council Greg Patzer Tom Culp