Picture please, where are these vents?

Could OP mean the OTR MWs that go over 36" ranges? They are 30" OTR MWs with "wings" to extend the width enough to go over 36" ranges. Just guessing. If that is what the OP means, I recommend against them.

Yes, I mean the kind friedajune talked about, Why do recommend against them, friedajune? Here's a YouTube link - I think you can watch just the last part.

https://www.youtube.com/watch?v=sIiCMo7s1OY

Sorry....wrong link. Here's the right one. You need to watch only the part at 29 and 30 seconds.

https://www.youtube.com/watch?v=pYFYmd-KMG4

Most folks here don't care for OTR microwaves, for a variety of reasons. First, they do not provide as much air flow as a dedicated hood - and if you have a 36" range, you probably need a lot of exhaust capacity.

Second, a MW at that height is inconvenient to use by one person, and especially so if one person is trying to use the MW while another is cooking at the stove. If your kitchen is big enough to support a 36" range, it's probably big enough to find another spot for the MW.

Finally, any time you combine functions, if one part of the unit dies, you have to replace both.

OTR MWs are great in small kitchens where there is absolutely no other option.

AnnKH hit most of the points. The other point is that you have to reach over hot food and, if gas, flame to use the MW.

In the vast majority of cases, OTR MWs are usually marginally effective hoods, at best, and mediocre MWs. In fact, if you watch the video in your link, even when the vent is extended, some of the billowing steam is missing the hood and billowing out into the Kitchen.

If you have a 36" range, then you really need a 42" wide hood. Hoods should be 6" wider than the cooking surface and at least 24" deep. A 30" range needs a 36" wide and at least 24" deep hood.

Assuming you're remodeling and not just replacing an existing OTR MW that's died, I suggest you post your layout here to see if we can come up with something better for you!

How do I ask for Layout Help and what information should I include?

• http://ths.gardenweb.com/discussions/2767033/how-do-i-ask-for-layout-help-and-what-information-should-i-include

New to Kitchens? Read Me First!

• http://ths.gardenweb.com/discussions/4306041/new-to-kitchens-read-me-first

That one at least looks like it would capture better than most, because of the pull out canopy, so if you have really limited options as to where you can put a microwave, this is probably a good option.

I prefer mine at counter height but I did remodel a kitchen where I used an OTR microwave because the kitchen had one run of 27" counterspace and one of 18" and I was not going to waste any of that on a microwave. (The entire kitchen was about 45 square feet, the size of some people's islands.)

It did actually draw quite well, despite the conventional wisdom in here. I know this because the temperature in the kitchen went up at least 15 degrees if you did not turn it on, and when it was first installed, due to a quirk in some existing duct work that we had to change, it discharged into an open vent in the powder room which was Underneath the kitchen on a lower floor. If you were sauteing in the kitchen with the exhaust on, if you went in the powder room you got a strong blast of hot steam that smelled like whatever you were cooking right in the face from the ceiling vent.

So, it had to actually be doing something for that to happen--and strong enough to vent against gravity,,,down, as well.

Does it work as well as a dedicated range hood with a large canopy? No. But it probably works better than the anemic range hoods that are all canopy with a little fan in the middle that I see as standard equipment in many new builds.

Thank you all so much - you raise good points. Off to do some thinking now...