Brad, of our construction group, recently became certified in Passive House Basics with a specialization in “Building Envelope,” making him a Certified Passive House Tradesperson. His expertise in air sealing and the building envelope is a practice that New Energy Works is implementing to continue building well-insulated and comfortable homes.
A Passive House is a super-insulated home that balances a comprehensive set of factors from design through construction (including heat emissions from the people and the appliances used, to the solar gains from window locations in the home) to reduce the amount of energy lost and provide a superior indoor air quality. We are continuously picking Brad’s brain on the latest design and construction techniques used to build high performance homes.
When building a Passive House, there is much to consider starting in the design phase and throughout the entire process. Location of the property along with the home’s orientation and outdoor shading are just the first steps to maximize solar gains and reduce energy consumption. Passive House building principals use innovative materials in all aspects of the process including intelligent air barriers, insulation, windows, doors and mechanical ventilation system. Special care even comes down to choosing the correct appliances, hot water distribution and energy efficient lighting.
In the construction phase, the Blower Door Test is a mandatory process in the Passive House practice, and has become a technique that we use frequently. This test allows us to pinpoint where there may be drafts and ensures a virtually air tight envelope while allowing water vapor to dry out and maintain an overall healthy environment.
How’s it work? Think of a nice big parade float in the Thanksgiving Day Parade. We wouldn’t want to see any saggy inflatables with air leaking out, so it makes sense to have a similar mind when insulating your biggest investment, your home. The Blower Door Test is used to aid in air sealing prior to insulation, post insulation, and a third time after finishes are complete. Put simply, a reversed fan pulls the air from inside the house outwards and gives an assessment of where there may be cracks and leaks in the envelope. This ensures complete air sealing prior to any drywall being installed and the opportunity to fix any issues.
How well-insulated is a Passive House home? The New York state code requires less than 7 ACH50 (air changes per hour at 50 pascals). Energy Star, a well-known program helping businesses and individuals save money and protect our climate through superior energy efficiency, requires less than 3.5 ACH50. Passive House has even higher standards, and requires less than 0.6 ACH50, making a Passive House 5 times tighter than an Energy Star home.
We look forward to learning more about Passive House and the evolving building techniques for high-performance, energy efficient homes.