Volume 50, Issue 6 - June 2015

Energy&Environment

Fenestration Plays Key Role in
New Passive Building Standard

Passive buildings generally are built so airtight and energy efficient that little, if any, energy is needed for heating or cooling. Fenestration products have a big part to play to help keep those buildings tight, so the Passive House Institute U.S. (PHIUS) has introduced climate-specific building standards for more than 1,000 locations in North America, from major metros to rural areas.

The standards are a result of peer review from the U.S. Department of Energy, public comment from certified passive house consultants and three years of work. It’s formally known as PHIUS+ 2015: Passive Building Standard—North America.


Peak
Performance


To determine a building’s passive building performance target, PHIUS+ 2015 takes these criteria into consideration:

• Annual heating demand (kBTU/sf-iCFA.yr)

• Annual cooling demand (kBTU/sf-iCFA.yr)

• Peak heating load
(BTU/sf-iCFA.hr)

• Peak cooling load
(BTU/sf-iCFA.hr)

• Manual J peak heating load (BTU/sf-iCFA.hr)

• Manual J peak cooling load (BTU/sf-iCFA.hr)


“We believe that PHIUS+ 2015 will make passive building more cost-effective across climate zones,” writes PHIUS senior scientist Graham Wright in his blog. “We got some good feedback on our standard-adaptation work—14 folks submitted some 50 pages of formal commentary altogether.”

Mike Knezovich, director of communications, says what’s next is “what we’ve been doing all along—trying to promote the adoption of the passive building standards.”


ASHRAE/IECC/DOE
North American
Climate Zone
Overall installed window U-value Btu/h.ft2.F Center -of-glass U-value Btu/h.ft2.F SHGC-
South
SHGC -
North, East,
West
8 ≤0.11 ≤0.10 ≥0.50 Any
7 ≤0.12 ≤0.11 ≥0.50 Any
6 ≤0.13 ≤0.12 ≥0.50 Any
5 ≤0.14 ≤0.13 ≥0.50 Any
4 ≤0.15 ≤0.14 ≥0.50 ≤0.40
Marine North ≤0.16 ≤0.15 ≥0.50 ≤0.40
Marine South ≤0.22 ≤0.20 ≤0.50 ≤0.30
3 ≤0.18 ≤0.16 ≤0.50 ≤0.30
2 West ≤0.18 ≤0.16 ≤0.30 ≤0.30
2 East ≤0.20 ≤0.18 ≤0.30 ≤0.30
As shown in the chart above, specific ratings are needed in order for a project to be passive.

They’ve done so thus far by testifying on Capitol Hill, training architects on passive building and even developing a program for builders to become comfortable with the strict air tightness needed to achieve the standard.

That air tightness doesn’t come without quality fenestration, says Knezovich. “The rating starts with the envelope. Air tightness in general is important, but there’s also the R-value of the window and frame. Those numbers are really key, and that’s why people are starting to use triple-paned windows.”

In the past, builders needed to import European windows to meet the standards. But now, Knezovich says, domestic manufacturers are stepping up to the passive plate.

Knezovich’s hope is that builders who previously dismissed the standard due to its single universal rating requirements will take another look now that there are more specified target numbers for each geographic area.

PHIUS now has custom passive standards for any climate in North America.
Source: PHIUS




USG
Copyright 2015 Key Communications Inc. All rights reserved.
No reproduction of any type without expressed written permission.