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Why would a vent-free heater be any more
unhealthy than an unvented gas range?

Sweepy This question comes up quite often, even though it is rapidly becoming a moot point, as more and more states now require vented exhaust hoods for all new gas range installations. Nonetheless, there are still lots of old, unvented gas range installations out there, so here are the facts:

It turns out there is a huge difference in daily exhaust exposure between unvented gas cooking appliances and vent-free gas heaters.

According to a study by the State of Illinois, a typical household gas range produces the exhaust from an average of 6.4 cubic feet (6,528 btu’s) of gas per day (this average is computed on an annual usage rate, and includes the peak usage season during the Holidays).

Vent-free manufacturers typically recommend limiting use to a maximum of three hours per day, so a 25,000 btu vent-free operated according to the manufacturer’s guidelines introduces the exhaust from 75,000 btu’s of gas into the breathing space every day during the 6-month heating season, for an annual average of 37,500 btu’s per day (nearly 6 times the average daily emissions created by an unvented gas range).


To read about how much CO2 a vent-free fireplace exhausts into the breathing space, click here.

To read about a recent study of the effects of long-term exposure to CO gases, click here.

To read postings from vent-free gas exhaust exposure victims, click here.

To read about respiratory irritation from vent-free exhaust in the breathing space, click here.

To read a posting about vent-free gas appliances from an indoor air quality scientist, click here.

To read exerpts from a recent Consumer Reports article about vent-free fireplaces, click here.

To read letters in defense of vent-free products, click here.

To read our opinion about vent-free gas appliances, click here.

Have a vent-free experience you'd like to share with the Consumer Product Safety Commission? Click Here.


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