Building Health Into Homes : Part 2 of 2
Building a home to a high level of indoor air quality starts at the very beginning with framing materials, glues, and plywood. It is not simply a wait to the finish stage and use Low VOC paints. We did a lot of legwork to find the best materials to reach our goal of maintaining excellent air quality for the Passive House project. Throughout construction, we meticulously researched how the products we used might affect air quality. We were able to use GreenGuard certified products for most of the materials used on the home. If a GreenGuard certified product was not available, we turned to other third-party certifiers of air quality. Some products we used were lab tested to ensure they would not negatively affect the air we breathe.
Some materials we used not only protected air quality, but helped to actively improve it. One example is the drywall we used. CertainTeed Air Renew drywall is a GreenGuard Certified product that actively absorbs volatile organic compounds (VOCs) and aldehydes, including the well known enemy formaldehyde. It then breaks these compounds down to a nonvolatile state and stores it them in a safe way for years. This is a great example of a forward thinking product that is helping to make healthier homes a reality.
Not only do the materials in the home play a role with air quality, but also the mechanical systems can make a dramatic difference. Such is the case with our state- of-the-art Zehnder ERV (Energy Recovery Ventilator), which helps bring fresh air in and remove stale air from the Passive House. The Zehnder system takes air out of the moist areas of the home that can develop odors, such as the kitchen, bathrooms, and laundry room. It then transports that air to the ERV where it bypasses the fresh outdoor air coming. In doing this, the ERV is transferring the heat (assuming winter conditions, and it will do the opposite in the summer) from the air, leaving the home to the fresh cold air coming into the home. It also is transferring some moisture from that outgoing air to that dry winter air coming in, thus keeping moisture levels stable. This system does not hurt the energy efficiency of the home because it is recovering 85% of that heat from the outgoing air. It also works with an efficient ECM motor that only costs $3 a month to operate 24/7. Imagine getting fresh air that is conditioned in your bedroom or living room all the time.
Studies in Germany, the origination of Passive House, show that people wake up feeling more refreshed with this type of system in their home, where they can breathe a constant stream of fresh air. Humans exhaust more carbon dioxide when they sleep than when awake. In a standard home, the carbon dioxide just hovers in the air, and in a room with a closed door, it can be difficult to get clean fresh air. An ERV system separate from the heating and cooling system ensures the rooms get a constant stream of fresh air and gets rid of the carbon dioxide. When you get more oxygen, you feel more refreshed, and thus get a better night’s sleep.
It was not enough to just use healthier building products and systems, so we went the extra step and did a post-construction air quality test. Two machines tested for S-VOCs, T-VOCs, formaldehyde, and other aldehydes. We also sent a cotton swab that had been run over every finish in the house to test dust particulates. I can say it took a while to compile enough dust in a home that we paid such attention to cleanliness on. These tests were sent to a lab in order to learn data on the air quality in the home. We will use this as a baseline data for all homes we build in the future to make improvements where we can.
This project was a pilot home for a new Healthy Home Initiative. This new Healthy Home Initiative inspected the home during construction and tested it post construction. It was exciting to be a part of the initiative, which is part of the Healthy Child Healthy World organization. They will use this data to educate other builders and architects on building healthier homes, but also will use the information to push manufacturers of building materials to scrap the old, “cheap” way of manufacturing building materials for a safer alternative at a competitive cost. This in turn proved that healthier materials to build healthier homes should not be the exception, but the norm.
We source materials with this logo in order to help assure the healthiest materials are going into our homes.