The Passive House, or Passivhaus Standard is one of the world's toughest energy standards. The NAPHN's "mission is to support and promote regional groups that promote the Passive House Standard to the public at large." Andrew Michler attended their recent conference; TreeHugger asked him to tell us what happened.
The first annual North American Passive House Network (NAPHN) conference has just wrapped up in Portland, Maine. It may be their first US conference but it was filled with many of the most experienced passive house minds on the planet, as well as some great local talent. The NAPHN is a nonprofit comprised of regional Passive House networks from Canada and the US, but with Dr. Wolfgang Feist giving the opening plenary and stake holders from a dozen nations presenting it had the feel of truly international event. It is still appropriate that the conference took place in the closest US city to Europe as there was a significant European contingency.The universalism of the standard has been a lively debate in the US with the domestic separate organization Passive House Institute United States (PHIUS) emerging with a flurry of tweaks and adjustments to the system, claiming the standard is not possible in such a varied continent. That question of universality was very much on Dr. Fiest’s mind when he took the stage, opening with a the statement that framed the entire conference “There is a broad set of climates worldwide but the physics is the same everywhere. This means that it’s the solutions that are different.”
You CAN build a Passive House in a hot humid climate.He quickly dove into the details of designing a Passive House in New Orleans where the challenge is the heat load and dehumidification. This is where the air tightness of the envelope takes center stage by keeping the humidity out. The fresh air exchange using an Energy Recovery Ventilator is also essential in providing humidity recovery from the outside back to the outside. Dr. Feist was quick to point out that with Passive House he learned to never avoid any type of HVAC system. It is essentially a performance standard so it best not to be too focused on specific technologies. That said it is hard to see most typical systems in the US like forced air and electric baseboard working to achieve the very low 4.75 kBtu square foot per year primary energy load. It is also important to note that the Passive House energy modeling allows you to go over that threshold for dehumidification in places like New Orleans. Good shading and insulation are very effective at reducing that energy demand. He highlighted a newly certified apartment in China, Bruck by Peter Ruge Architekten has even longer stretches of high humidity and how the building helps reduce grid peak load as well by slowly conditioning the building through the day rather than the spike in demand using typical in air conditioning. Comfort as a design goal came up again and again as he spoke of the standards value.
Pushing the building envelopeThe Passive House really pushes industries to develop new technologies and practices as Dr. Feist pointed out that if his first building built in Darmstadt in 1991 had contemporary high performance windows the wall thickness would be reduced from 25 cm to 12 cm. Now the same thing is happening in HVAC where systems can dehumidify, heat and cool by optimizing the system with the specific loads. Breaking out his smart phone he compared the energy it took to run a supercomputer in the 1987 to what he could compute today with a nominal energy demand. The big reveal though is the new renewable energy ratings. Passive House Plus is a net zero energy certificate and Passive House Premium is energy positive. The challenge is not energy production but optimizing storage. Dr. Feist pointed out if you are simply are looking at PV then the optimized building form factor is wide and flat which is not very good for buildings to reduce energy demand- not mention a poor building topology for cities. A well dayit compact building works much better in reducing the energy needs in the first place and cheaper to insulate. Most places in the world still require the most energy to heat, and since it is hard to store energy in the summer for the winter the new Passive House energy standards will emphasize low demand with dynamic energy production and storage. This means different loads will be calculated and designed based on onsite production and storage capacity.
Tapping in to European know-how."The conference really provided Americans the opportunity to tap into the European knowhow. After all Passive House is becoming code required in many cites so the level of insights is fantastic. Frankfurt for instance now requires all city buildings to be certified, claiming they cannot financially afford not to do it. But the opportunity for stateside companies to find their own forms of optimizing design, construction and technologies is being demonstrated right in Maine. We swung by Ecocor, which is making Prefabricated Passive House low embodied energy and low cost homes. The shop is out in the beautiful countryside where they are taking tried and true Passive House methodologies and adding some Yankee knowhow to make homes with local talent and materials. A good sized China contingency was there as well to introduce their projects and even Chinese designed and manufactured passive house windows.
I ran into a dozen folks who I met for the first time but recognized me or I them from twitter (@andrewmichler BTW) so it was a lot quicker to get up to speed. Use the hashtag #NAPHN14 to catch some of the insights and conversation. What makes this work is Passive house is a universal system so we are all talking the same language even if we don’t have other things in common, like hot sauce on pancakes. The cross pollination of ideas and opportunities to save real energy and money at the scales we need to be effective is the goal, and after a great few days in Maine I am more optimistic than ever about the capacity of us to make that a reality. At least once I recover from the parties.
Andrew is a writer and sustainable building consultant based off grid in the Colorado Rockies. He is currently writing the book Hyperlocalization of Architecture about the next phase of worldwide environmental building design based on place, published by eVolo and due out in Spring 2015. His work in Passive House includes designing and building his own project and helping to provoke and mature the market nationwide in various roles.