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Community and Q&A

Over-the-range vent uses same vent as dryer – condensation issues

Lekili | Posted in General Questions on

My current range hood uses the same vent as my dryer, and can’t be changed (I live in a condo) I am replacing the range hood with an over-the-range (OTR) microwave. Other people in my building have told me they have had issues with the microwave filling with condensation from the dryer. To prevent this they have the range hood vent back into the kitchen. I would prefer not to do that, is there anyway to prevent the condensation from back filling into the microwave?

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  1. user-2310254 | | #1

    I can't imagine that mixing grease and lint is a good idea. I would either installing a recirculating kitchen fan (and cut back on the frying) or a heat pump dryer (which does not require venting). Actually, a heat pump dryer would probably improve your energy usage a bit as well.

  2. JC72 | | #2

    Please for the love of god do not replace your range hood with a microwave. PLEASE DONT DO IT !!!!!

    However I can't help but wonder if you have a fire hazard on your hands because I would think lint from the dryer vent would attach itself to the grease buildup on the interior walls of the duct. *shrug*

    As for you issue I would inspect the wall cap on the exhaust duct. Replace it with a cap that has louver door/damper which will help reduce interior air leaks from the outside.

  3. Expert Member
    Michael Maines | | #3

    In no case should the two ducts be combined. Very, very high fire risk for several reasons.

    Steve's ideas are both good ones. If the range is fueled by gas, you need an exhausting range hood, so if that's the case you should change to a condensing dryer. If the range is electric you can keep the exhausting dryer and use a recirculating hood.

    John, I used to feel the same as you above microwaves over the range, and have talked many clients out of that arrangement. It was the only option when I renovated my own kitchen, and it's nowhere near as bad as I thought. Granted we don't have kids, installed it well above the range, and use it only for reheating the occasional meal. Actually the microwave portion broke after two years (Don't buy LG appliances) and we quickly got used to not having one at all.

  4. JC72 | | #4


    I get it.

    I've been living with an OTR microwave for most of my adult life and I completely despise it. I wish I could make them illegal but that would make me a statist. (lol).

    It's just incredibly limiting when it comes to cooking.

  5. STEPHEN SHEEHY | | #5

    Don't assume that just because you live in a condo, you can't fix this. Send a letter to the condo trustees and point out that the existing situation is dangerous and needs to be fixed before the place burns down.

  6. Expert Member


    As Stephen said, this needs to be addressed by your condo board. If all the units have the same problem they all need to be remediated. It's dangerous.

  7. GBA Editor
    Martin Holladay | | #7

    This installation violates the installation instructions provided by the dryer manufacturer and also violates the installation instructions provided by the range hood manufacturer. Violating these instructions amounts to a code violation, making this installation both dangerous and illegal.

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