What do you mean by "in my wall unit"? OTR microwaves can be installed over countertops or cooking surfaces. They cannot be installed such that the bottom, with lights and fan intake, is blocked off.

If you don't like the look of trim kits, there are plenty of ways to get around using them that don't require an OTR or putting a microwave on your countertop. You can get a microwave/wall oven combo. You can get a microwave drawer like Sharp. Or, you can create an alcove for a microwave large enough so that it has room to breathe without needing a trim kit.

Why would you want a 30" countertop microwave? That would just be a waste of counter space. The only reason OTR microwaves are made in 30" is to match the size of the ranges they're designed to be installed over. That is an exterior measurement only. 24" countertop microwaves are available that have at least as much capacity as an OTR.

hvtech 42, I don't want the microwave on my counter. I want it to be built in above my wall oven which is 30" wide which is what I'm trying to match. Most of the microwaves that I have seen that are 30" are over the range microwaves or under cabinet. I do not want the oven/micro combo. I'm sorry, I don't know what you mean when you say alcove. Can you please explain that option. Thank you for your help.

If you want a MW installed in a cabinet above your wall oven, buy any countertop microwave whose manufacturer makes a trim kit to go with it. I do not know why you don't like that idea. In any case, Panasonic and Sharp are the two leading names of MWs with trim kits.

An OTR MW is constructed to be hung over a cooktop; it cannot be installed inside a cabinet - even setting aside that the lights and fan cannot be blocked off, the lights and fan do not provide a flat smooth surface to lay on a cabinet floor - the OTR MW must be suspended. Furthermore, an OTR MW is 30" wide; therefore your cabinet to house it (if this sort of installation were even possible) would have to be several inches wider than that

I cannot imagine why you "like the look of an OTR MW better" than a non-OTR MW that is designed to allow for wall cabinet installation and trim kit.

I think what HVTech means by alcove is simply an open shelf in your cabinetry that you set the MW in. That way, you are not paying for an expensive trim kit, and, when the MW breaks (they are not built these days to last more than a few years unfortunately), it is an easy switch to install a new one - simply unplug broken one, remove, and plug in new one.

This post was edited by Mrs_Nyefnyef on Thu, Nov 27, 14 at 11:13

^Great answer/explanation. That's exactly what I meant by alcove. Some people don't like the look of trim kits because of the ventilation slots above and below the microwave. Those same people might take issue to an alcove as well though, because the microwave doesn't really look integrated/built in and there is a lot of empty space around it. The sleekest way to get a microwave above a walloven is to buy a pair that are attached at the factory. That's what I have in my kitchen. Of course, that has its own set of disadvantages. Down the road, the microwave will almost always fail before the oven, and you won't have the freedom to just chuck it and buy a new cheapo one from Walmart. You'll either have to pay big bucks to repair it, or big bucks to replace the entire oven/microwave unit.