Sometimes our clients’ desires work against them: They want commercial-grade stoves, requiring large rangehoods in their kitchens; they want inexpensive heating appliances, which often don’t have sealed combustion; and they choose furnishings and finishes that off-gas noxious chemicals into their homes. What’s a remodeler to do?
Michael Sauri, owner of TriVista USA, in Arlington, Va., says that he deals with the rangehood problem in many high-end projects. He renovates homes to be tight, but he needs to find make-up air to replace the air — as much as 1,200 cfm to 1,800 cfm — that large rangehoods can pull from a home, depressurizing it and causing furnaces, water heaters, and other combustion appliances to backdraft nasty gases.
Several green-building experts asked about this issue agreed that commercial cooktops are not intended for residential use, and there is no product out there that solves the problem. But it’s unlikely that clients will stop wanting large-scale cooking equipment.
Part of the solution might be to choose sealed combustion heating appliances. This type of equipment pulls in fresh outside air through a sealed pipe, and vents flue gases through another sealed pipe, virtually eliminating backdrafting.
When Michael Anschel’s Otogawa-Anschel Design + Build clients want “fancy high-end six-burner ranges,” the Minneapolis remodeler says he installs a large cooking hood fitted with a smaller blower that’s still within code. “Unless you’re the Iron Chef and you’re using all six burners at once and you’re frying salmon on three of them, there’s no reason to put a large-cfm blower unit on your vent hood,” he says.
Joking aside, finding healthy air for homeowners is more than a rangehood issue.
According to Environmental Protection Agency (EPA) studies, “indoor levels of pollutants may be two to five times — and occasionally more than 100 times — higher than outdoor pollutant levels.” It’s not only appliances that off-gas pollutants into homes; so do vinyl shower curtains, foam pads in furniture, carpet pads, paints, and cabinet glues.
Some toxic substances can be ventilated out of the house, such as VOCs (volatile organic compounds) in paints and chemicals in flexible vinyls, but substances like flame retardants that don’t give off an odor are more difficult to get rid of.
Designer Cindy Ojczyk, owner of Simply Green Design, in Minneapolis, suggests talking with clients about healthier material options. In addition to using high-performing low-VOC paints, she prefers to look for labels such as the Carpet and Rug Institute’s Green Label Plus; NAUF (No Added Urea Formaldehyde) for wood; CARB (California Air Resource Board) for products that have reduced formaldehyde; and Floor Score for resilient floors such as linoleum and vinyl.
In terms of air quality, though, Ojczyk says, “We can address formaldehyde all we want, but if carbon monoxide is leaking and you change the house in some way, you can put the homeowner at risk of death.”
TEST IT OUT
Anytime you insulate a house, you should do a “worst-case combustion spillage test,” Anschel says. It’s not required, but it’s a simple way to see if you’re putting your client at risk — and it will let you know whether you’ll need to replace appliances.
The new version of the U.S. Green Building Council’s LEED for Homes, which will be released later this year, requires make-up air. For help, consult ASHRAE (American Society of Heating, Refrigeration, and Air-Conditioning Engineers), which has a formula for whole-house ventilation (see sidebar).
Who rules the air depends on how proactive you are in studying indoor air quality issues and discussing them with clients. —Stacey Freed, senior editor, REMODELING.