A panel discussion looked at essential components to achieve passive house certification at the North American Passive House Network (NAPHN) Conference, held in downtown Vancouver on Oct. 1.
The panel consisted of NAPHN co-president Brownyn Barry, Ken Eklund of the Washington State University energy program and Barry Stephens, the development and technology director of Zehnder. Barry began by explaining that windows remain the weakest link for passive house, and that even Germany's windows aren't high enough quality yet. However, there has been some progress in North America, but Barry stressed that durability is key. Hygiene and comfort also has to be included in criteria, she said.
To get these windows in North America we can import, but that isn't a long term solution, she said. It is important to provide incentives to local manufacturers to increase demand. Incentives could include waiving local code requirements for PHI certified windows and providing assistance to local manufacturers.
Ecklund said that "climate change is a market reality," pointing to old refrigerants (which have high global warming potential) in Japan and Europe are on their way out, with the rest of the world following their lead. New refrigerants including (ironically) CO2 must be adapted, he said.
However, the process barriers include having to have a marketable product and needing it to be cost-effective. It is generally the ratio of the benefits to the costs. Benefits are usually discounted to present value and costs may be offset by credit,s such as the electric water heater that was not purchased.
Considerations in cost effectiveness include "stackable values," he added. For example, if technology, demand response and capacity benefits, it should not be evaluated on efficiency alone.
CO2 "split systems" for refrigerant will soon be available, Ecklund said, and preliminary analysis shows cost effectiveness as a water heater based on efficiency and capacity values.
Stephens said applying passive house methods related to heating means dealing with the heat recovery rate of the exhaust air stream.
If heat recovery isn't addressed, you're "throwing out all your other efficiencies" he said.
Sound attenuation, cross flow leakage threshold and the motor power threshold are all important considerations when adapting to passive house standards, he said. The threshold for passive house certification is very high, Stephens said, so making those components conform to Energy Star and other certifications doesn't make sense. The way forward, he said is to equal Energy Star with Passive House Institute certifications.
The 2015 North American Passive House Network Conference (NAPHN15) is taking place Oct. 1-2 at Hyatt Regency Hotel in Vancouver, B.C. Check back for more blogs, stories and videos from the conference.