My gas oven is only partially heating while I run my evaporative cooler. I can also smell gas when both these appliances are on. My first thought is that perhaps the combustion air intake is partially blocked, and the air movement from the cooler is enough to suffocate the flame. However, I can't find where the oven draws combustion air from.

From where does an oven draw combustion air?

2 Answers 2


Home gas ovens draw oxygen from room air, and in turn add CO2, some CO, a little SO2 (from impurities and warning smell additive) and perhaps some nitrogen oxides to the room air. An externally vented exhaust hood helps get rid of these combustion products.

Most homes are not so air-tight that use of a stove or oven (other than on self-clean cycle) poses an issue. However, there may be local recommendations or requirements for air exchange, but "in the United States, venting most residential gas ranges and cooktops to the outside is not required."

So, if your evaporative cooler is vented, and the airflow interferes with the oven, you may need to operate the range-hood fan or crack a window (admittedly reducing the efficiency of the swamp cooler).

  • Thanks for the answer. How does the room air get into the actual oven? Intake duct somewhere near the bottom, I suppose? Jun 8, 2020 at 22:23
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    The door is not airtight. Air must move through the oven to prevent stratification of temperature. Jun 9, 2020 at 1:39
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    A home gas oven is relatively open on the bottom . There will be a vent on the top, usually at the rear to let the exhaust out . I often use this heat to keep some dish warm. The oderant is ethyl and/or methyl mercaptan, probably less than a ppm so the amount of SO2 it makes may not be notifiable. It should not make any CO. Jul 9, 2020 at 1:23

I wish to qualify this post as written by an individual with residential, commercial, and industrial building experience, however, I am not an mechanical engineer nor do I hold a PE license in an engineering field. I do as much of my own design, procurement, maintenance, and construction in my current phase of life - farmer, rehabilitation of this old house, this old farm, these old outbuildings.

That brings me to the topic of gas range ventilation. We’re remodeling this old kitchen in this old farmhouse and I am adding a commercial-style, LP-fired, range. I’ve oversized the range hood, one with an in-duct exhaust fan to reduce kitchen noise so I’ll be able to hear myself sing while I cook. There’s ample information available on “how much exhaust air do I need”, measured in CFMs. I general guideline is one CFM of exhaust for every 100 BTUs.

What I haven’t found readily available, and the range and hood manufacturers do not wish to commit to, is a guideline or design for make-up air.

So here’s what I’ve designed: the home has a crawl space, I’m adding make-up air via ductwork under the house, adding gridding and screening to keep the unwanteds out, an air pressure activated damper in-line and accessible for any future maintenance. The range will be on a peninsula for now, moving to an island in a future phase of renovation, and my choice is to put the make-up air register in the lower cabinet behind the range. It will also be accessible for cleaning, inside vertical surface of the pocket that the range fits into, such that material from the floor doesn’t fall into the ductwork. The oven draws air from below. The range top draws air from around the burners.

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