Hi David -

I know I'm in the minority, but I really dislike the look of a ”hood” (any hood) over the stovetop…but I absolutely require strong ventilation power.

With that said, we installed the over-the-range microwave with what LG calls the ”extend-a-vent” system (pics below). It’s amazing.

We have ours vented directly outside, which is a must for us, and we couldnt be happier.

BTW, we have a 36” 5-burner (one of which is 22,000 BTUs) gas range.

The LG is also 400cfm, but the way the vent operates (extends forward, and angles down in the back when in use)…and the fact that it is vented outside, combine to create a very high performance level. It’s better than many of the traditional hood-types due to its ability to cover the entire area above the cooktop.

It has a very large capacity, easy clean, extra shelf/rack, and the control panel is across the bottom for much easier access.

I also like the look of it better than any hood, and love the placement of the microwave above the stove. I know, I know; I said I am in the minority!

Just thought I’d let you know about it in case you hadn’t discovered this option. Hope that helps!

I find I use my microwave less and less and certainly don't need the large capacity the comes with an OTR microwave. I would recommend an exhaust hood. They can be very minimal like the linear one from Broan. I would select a microwave that simply sits on a shelf somewhere in the kitchen

We have a 600 cfm insert over our 36" rangetop, which is about as high as we could go without needing makeup air in my city. Before you make any decisions, confirm you can vent to the exterior, and confirm your makeup air requirements (and how much you want to spend on that, if anything). Some municipalities require makeup air for anything over 400 cfm. If you go bigger, you will probably need a bigger duct, so it also depends on whether you can place that.

Thanks for the info on the LG, as well as for makeup air. There is already an exterior vent on the wall, but the current microhood isnt enough for any broiling, and cleaning the oven requires turning on other fans and opening doors.

ive got a couple other spots for the MW, and can go built-in for a wall or shelf, under the island/peninsula or even on the counter.

I don’t think you have enough room over the range for a microwave hood. You would constantly be cleaning the underside of the microwave. A shallow hood with good suction is all you need. Put a countertop microwave elsewhere in the kitchen.

I agree a proper hood vented outside and IMO you need more than 400CFM if you do indoor broiling often. Cleaning the oven if done before it gets gross usually is not an issue since wall ovens have no outside venting and mine never set off the fire bells. I can't tell how much I dislike OTR MWs they are useless and dangerous to use in that position and will die long before a good hood so then the search will be on for one that fits the space .

We have a 600 cfm Bosch hood (not insert, no cabinet). We did not require make-up air. It vents through the ceiling and out the side wall about 5' away. Our stove is a five-burner gas Bosch. The vent works fine, but is noisy, particularly at the higher speeds.

I see a lot of info about needing makeup air over 400 CFM, but not sure how to do the calcuation. The kitchen cabinet area is 11X13, but the full kitchen is 21X13, and opens to a family room that's 21X15.

We have a gas fireplace, range (main floor), water heater and furnace (basement), with roughly 3000 sq ft of finished space. I can't see going over 30" for a replacement oven/range unit. This unit would be on an outside wall and vent direclty.

@David Hollingsworth You need to look up the HVAC code for your municipality. I'm not a pro but I've looked into this quite a bit. The international residential code has a blanket statement that any hood installed with CFM>400 needs a makeup air system. Your municipality may adopt this code, or they may write their own (or they may have no requirement). In my area, the state has written their own code for this, and the calculation is based on square footage of your house and the number of gas appliances without direct venting. So, in our case, we can have a 600 CFM hood, which is below the maximum CFM for our square footage (barely). If we had a smaller house or a larger CFM hood we would have needed makeup air.

Fairfax County says that a makeup air system is required for any fan that generates more than 450 CFM, regardless of house size.

Now, that makes for a good question - how much CFM do I actually need for a 30" 4 or 5 burner gas range? All I know is that my existing microwave hood SAYS it pulls 400CFM on high, but I'm still using the smoke alarm as a timer. I'd like to be able to cook without setting it off.

The range / vent is on an exterior wall, so if we needed a MUA system, it could pull air from that side and bring it in either over the top of the cabinets or down from the ceiling. I'd have to look up how close a system can be to the vent, though. I wouldn't want to pull the smoke right back in.

I can’t speak to the makeup air (mostly because I’ve forgotten what I learned when we built our house) but I would 100% suggest using a standard hood vs a microwave combo. My son has the latter and we can’t even touch the handle when there are things cooking in the stovetop below. Our last two microwaves have been shelf mounted, not built-in, because I thought the size variations would make it more difficult to replace a built-in. Maybe that’s not a good reason, but I (used to) think that microwaves don’t last as long as other appliances. Good luck with your project.

We think a dedicated vent hood might work well in your situation. Here are some ideas from various designs of ours:

Bonnie Brae Kitchen Renovation · More Info

Denver Townhome Renovation And Decor · More Info

Observatory Park Home Renovation & Decor · More Info

Evergreen Design and Decor · More Info

I would also suggest a hood. Just having the bell of the hood will help with the problems you are having since it is able to capture the air. I would also suggest going to a 36" wide which also makes the capture better.

The other thing to consider is when are you turning the hood on. If you wait til you put the food under the broiler then it's too late. The fan needs a chance to create an air flow to remove the fumes.

If you want a quiet fan, then look into a remote blower. The motor mounts outside the house so it is quieter inside. This will also depend on where you install it. Ask your appliance specialist about it.

Good luck!

I have a Best vent inside a decorative hood and it does an awesome job. 3 settings of fan speed and high practically sucks the cook out! I was told to turn the vent on 10 minutes before cooking to create the proper airflow. Good luck!