Kitchen range hoods – air quality concerns

So this one’s from back in September, but hey, I’m not above posting something from way back when. Kitchen range hoods – they can be quite horrible and not even worth having, except as an item to check off a list. Many range hoods are installed solely to collect the aersolized oil droplets and water vapour that come off a hot pan during cooking, and then re-circulate that air into the kitchen. Also, most of the fans are quite low-cfm – in the range of 3-400 cfm – suitable they say for non-Asian cooking and even for low-BTU gas stoves, but not if it’s just recirculating the air.  And then there’s the noise of the fan. Ugh.

It actually raised a lot of trouble for me when we decided to renovate our kitchen – finding a suitable range hood took quite a lot of research. And then in the end, we still didn’t get what we wanted – a quiet hood with high-cfm (maybe partly due to our limited selection available here in Canada, and I didn’t want to go through getting it from the US). I did get it to exhaust outside of the house though.  Seems like you can have either a low-noise or high-cfm fan, unless you have lots of money.

It’s quite refreshing to come across this article on NPR that talks about indoor air quality concerns, especially with gas stoves. Indoor air quality is starting to become a larger concern in homes, considering gas furnaces and hot water heaters can give off carbon monoxide if they malfunction. Then there’s mold and mildew, off-gassing of new products in a home, etc.

Cooking on a gas stove releases some of the same pollutants that you find outdoors in smog. Logue looked at homes in Southern California that cook at least once a week, and found more than half of them were above the outdoor health limit for a pollutant called nitrogen dioxide.

“If you exceeded the standards outdoors, it would be a really big deal,” she says. “But if you exceed them in your house, nobody’s paying attention.”

Homes with electric stoves aren’t in the clear because cooking the food itself creates air pollution. Sauteing fats produces a lung irritant called acrolein. And cooking puts off .

The good thing is that ventilation guidelines can be found at the Home Ventilating Institute (HVI) publications section. They recommend getting a range hood fan that can do 15 air changes per hour.

For adequate ventilation, the Home Ventilating Institute recommends these guidelines for air changes with wall or ceiling exhaust fans: kitchen, 15 changes an hour; bathroom, 8; family, recreation or laundry room, 6.

To calculate the CFM capacity of wall or ceiling fan which will deliver the needed air movement, multiply floor area by the appropriate factor, as follows (assuming an 8-foot ceiling): kitchen, 2; bathroom, 1.07; family, recreation or laundry room, 0.8.

A different basis for selection applies to range hood fans. Recommended minimums: 40 CFM per lineal foot of range hood for along-wall placement. Higher ratings than minimums often are desirable.

A great resource for finding out the tested noise levels of range hood fans can also be found at the HVI site at their HVI-Certified Products Directory.

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