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  microwave with outside vented exhaust
microwave with outside vented exhaust Sign In/Join 
We recently purchased a home with a built in microwave/exhaust appliance over the range. It vents to the outside.

As the weather has become quite cold we have noticed cold air is coming in from the outside through the microwave vent. The metal of the appliance is very cold to the touch.

Is this normal for an outside vented exhaust? How much energy could we be losing this way, and is there anything that can be done to prevent it?
Posts: 6104 | Registered: Jul 20, 2009Reply With QuoteReport This Post
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Check on the outside of the house if there is an exhaust vent. (Probably looks like a dryer vent?) It should have a baffle that closes it off when not in use. Sometimes these are missing or stuck open.

If not on the outside, then it might just vent into an attic space. Same thing, look for a baffle that closes. If it does vent directly into the attic, this is not the best situation, especially if you live in humid, not arid climate. Excess moisture exhausted in the attic can cause ceiling and insulation damage.
Posts: 9678 | Location: Plains & Mountains | Registered: Jun 08, 2003Reply With QuoteReport This Post
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We had that problem with the outside vent in MN. It was not a micro but a regular vent.

It is not normal. Fix is what Conrad said. But in the meantime cover it on the inside. There is a filter on the bottom of the micro. Take it off as if you are cleaning it. Cover with foil, letting it extend beyond the filter as much as you can and still hook it back on. Once it is on push the foil that is sticking out up to the bottom of the micro.

It will not cut off all the cold air but it helps. We had to do it for several months before it warmed up and the snow melted enough to get someone up on the roof.
Posts: 7282 | Location: North MN & Northern AR | Registered: Oct 01, 2002Reply With QuoteReport This Post
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thanks for the help! Unfortunately for us- this is a Condo which means any exterior stuff has to go through the HOA. But at least I know how to explain the problem to them. Wish me luck!
Posts: 6104 | Registered: Jul 20, 2009Reply With QuoteReport This Post
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Update- I brought this up with the HOA. Apparently there is no baffle/damper with the outside venting. There has never been a year this cold so apparently it has never come up. The HOA board is "looking into options"

I won't hold my breath. I'm just glad it's warming up now.
Posts: 6104 | Registered: Jul 20, 2009Reply With QuoteReport This Post
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My microwave is also vented to the outside and like others here, it lets in cold air..even the microwave has had trouble starting when it's been really cold! We've lived in the house for 20 years and never had an issue with the cold before...I guess because it's been exceptionally cold.
Posts: 2 | Registered: Jun 18, 2013Reply With QuoteReport This Post
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