I don't know of an OTR MW that would provide you the CFMs you'd need with that range. I don't know what Electrolux recommends but I personally wouldn't be comfortable with less than 600 with an all-gas range.

Before you do anything though, you should check the diameter of the existing exhaust duct - if it's less than 6", you might have to reconsider your range choices.

The captain is right, but something is better than nothing.

A lot will depend on what you cook. If it's usually boiling water for pasta and simmering sauces then that unit will likely be fine. Making tandoori ,or frying fish and onion rings and you're going to smell up the joint and fill it with fumes.

In addition to he size of the duct , how long and straight it is will also impact the ability of any hood you choose.

In smaller spaces such as you've described it's not uncommon to have to balance exhaust CFM's against lack of make-up air. If your condo is really tight, it may not matter what the CFM exhaust volume is. If the air can't flow, all you end up with is a low air-pressue in the room until you turn the fan off.

OTR microwaves are pretty much of a joke exhaust-wise. They do post their CFM capabilities, typically 150-400 CFM, but mostly they just sit there and make noise.

One trade off you may consider to balance the lack of make-up air thing is a larger capture-area of the hood. I agree with captsmethwick that 600C CFM wold be a good minimum. However, if that results in too much negative air, even 400CFM with properly-designed hood / capture-area can do a lot of work.

A difficult problem to be sure. I wonder if there is even room for the make-up air components, if required.

If so, then there is a possibility of oversizing the MUA to aid the exhaust system. This assumes that the microwave is not just recirculating air, but actually exhausts it somewhere outside.

Or (or maybe And) the flow from the microwave can be augmented. For many years before the latest renovation, I used a roof exhaust fan at the end of the duct fed by a microwave like cookcenter system. This considerably helped the air flow, perhaps raising the nearly useless flow rate to something merely inadequate. Incidentally, this roof fan has been reassigned and is now pulling air from the ceiling in front of the wall ovens as a supplement to the island hood over the cooktops.

kas

Thanks so much to everyone for all the great help and advice. I guess we really have to do some research! It's sort of discouraging to think we would have to get a wimpy range if we can't do a hood. I'm not even sure a hood would be possible in a bottom floor condo. Fortunately we aren't doing anything right away, so we can take our time. Really appreciate the help!