# Venting a Microwave/Range Hood Outside



## oh'mike (Sep 18, 2009)

If you know the EXACT location of the new micro wave will be --your idea will work---

this is best to do after the cabinets are up or you may locate the opening in the wrong spot.

nice heavy microwave vents are available for 2x4 stud walls.

Before the cabinets go in--check for studs and wires in your way---You may need to 'header in an opening ' to locate the vent where you want it.

Another option is to have the vent go up into the cabinet above---and use a 3 1/4 x 10 addapter to 6" round and exit with a round vent.---This makes a waste of the upper cabinet,however and requires you to make a wood cover to hide the duct work.


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## jklingel (Dec 21, 2008)

be careful w/ the cfm on the vent motor. some of these 800+ cfm fans cause negative pressure issues. if your house is super-tight, you may need to install a make-up air vent as well.


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## hellothere123 (Aug 16, 2008)

I opened an old vent when installing a new micro/range hood...Then in winter I had a huge ice dam on the roof where the vent was - it created a leak...for some reason I had trouble sealing the outside vent, so I closed it up and switched it to use the internal filter to clean.

I probably use the vent part about 1 time every 10 years, so it made sense to do it this way.


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## sweaty (Jul 18, 2008)

With the old hole, I would seal it up with expanding spray foam.


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## Ron6519 (Mar 28, 2007)

The plan you have for the new installation sounds fine.
You didn't mention the electric, so I guess you have that covered.
The old vent hole should be completely closed, both the exterior and the interior. You want to eliminate any openings in the house you don't need.


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