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For indoor environmental quality concerns to reach the broader market and change the way we build to the extent that Energy Star has accomplished a sea change in the efficiency of homes, programs like the EPA’s Indoor airPLUS will have to pass muster among builders. Right now, the program remains in the early adopter stage, with only a few builders (about 400 nationwide) participating. By and large, builders remain unaware that tightly built, energy-efficient homes may require a sharpened focus on indoor environmental quality.
This is why I contacted Mike Murphy, president of Nexus EnergyHome’s construction division. An Indoor airPLUS builder, the company won recognition as the NAHB Research Center’s EnergyValue Housing 2012 Builder of the Year, and also the Gold award winner for New Homes. Nexus builds net zero-ready homes and subdivisions, claiming they can accomplish this level of energy performance while remaining price-competitive with standard market offerings. The company also includes a standard array of indoor environmental quality features that include central vacuum and HEPA air filtration systems, energy recovery ventilation, radon mitigation, and low-VOC building materials.
To earn the Indoor airPLUS label, a builder must first design a home to earn the Energy Star label and then add up to 30 design and construction features that help protect qualified homes from moisture and mold, pests, combustion gases, and other airborne pollutants. Before the home officially earns the Indoor airPLUS label, an independent third-party inspector must ensure compliance with the EPA’s guidelines and specifications.
En route to becoming an Indoor airPLUS partner, Nexus spent three years working in partnership with the NAHB Research Center, investigating how to build homes meeting net-zero as well as the EPA’s IAQ standards. “Since our net-zero capable homes by definition require a nearly airtight building envelope in order to function at the energy-efficient level required to gain those standards, we knew from the start that indoor environmental quality would become an essential component in the building recipe of a Nexus EnergyHome,” explains Murphy.
Following the company’s research with the NAHB, it went further independently, learning not only how to move air properly through a home, but also how to clean it at the same time. “We started by looking at the EPA’s website and learning about the parameters of what constitutes the standard for clean air. The EPA’s standards led to researching high-technology products for filtering air, where we identified HEPA as being the most advanced and comprehensive air-filtering system. Once we knew how to clean the air, we identified the Energy Recovery Ventilation system as the best technology for moving the air through the home,” Murphy says.
Nexus selected building products with low to no VOCs, including: paint, spray foam insulation, all adhesives (including SIP adhesive), waterproofing, carpets, plywood (floor and roof sheathing), flooring and dry wall, explains Murphy, to reduce or eliminate any adverse impact on air quality that can affect occupants, “especially sensitive [occupants] such as children, the elderly, and those with compromised immune systems or respiratory conditions.”
According to Murphy, Nexus homes have rated “through the roof” in terms of tightness, achieving approximatly one air change per hour (ACH), compared to typical homes that have five to six air changes per hour (ACH), “and we are working on getting that down to about .7 (ACH),” says Murphy, which would put them in striking distance of Passive House standards. Murphy also claims the company has minimized duct system losses to no more than 6%, where typical homes suffer between 25% to 28% loss through leaks in the distribution system. To achieve these standards consistently, Nexus devotes a lot of time to product analysis, construction staff training, continuing education, and management of strict quality control. “This is an ever-evolving process,” says Murphy.
Murphy finds that home buyers respond with “great enthusiasm and support” for the firm’s healthier homes. “It’s something they can really put their hands around, because allergy and respiratory illnesses are epidemic and rising, and they understand the impact that having cleaner air can have on their health and their overall well being,” says Murphy.
This integration of air quality consciousness into the building process--delivering clean air to homeowners by design, rather than offering a few add-ons to mop-up dirty air--is exactly what the EPA hopes to achieve with Indoor airPLUS. “We have seen a recent increase in program participation and believe that as home owners gain more understanding of the link between health and their homes, the Indoor airPLUS label will continue to increase in demand,” says Rachel Runnals, spokesperson for the program.