I wouldn't bother with a recirculating vent. You need fresh air to dilute contaminated air and to exhaust contaminated air, steam, etc. If you can't do a down draft I would install a side mount exhaust fan through the wall or ceiling at a more convenient location.

Thanks for your advice. Do you think I can use a dacor downdraft (much slimmer) with a thermador range? Or do they need to match brands?

I don't think the brands matter. Just look for one that will work with your specs. Get a downdraft matched for your range size and one that raises up the highest (helps it work more efficiently).

I had a similar problem and down drafted with a remote in line fan. It is very quiet and very powerful. It also ducts through the crawl space.

Ductless hoods are worthless! If you really do cook, you need an island fan if downdraft is not a possibility... I finally had to go commercial. If your ceiling is not real high, you will be fine.

In your discussion post of Oct. 22, 2013, “Trouble venting
island range,” there’s a photo that includes what looks like a
Mullins-Youngstown 66” double sink, inset on a countertop and sitting on
cabinets. If so, I’ve got some
questions: I have such a sink on its
original metal cabinet base. I’d like to
keep the sink in our kitchen renovation, but it needs some work. Did you have to refinish or resurface yours? If so, how did you accomplish that and how
well is the resurfacing holding up? As
for the cabinets: did you discard the metal cabinets? How difficult was it to get cabinetry to go
with the sink?

As to your original reason for posting: I’m also having to consider
a downdraft vent system. I’m looking at a Dacor 30.” What did you end up doing? How satisfied are you with your choice?

I’ll appreciate any advice or information you can
supply. Thank you.

i have a 36" thermador downdraft that i like very much.

I will contact the previous owners to find out about the sink and cabinets as these were in place when we bought our house two years ago. As far as the venting goes, we still have not done anything because it looks like we could vent a true exhaust hood vertically through the roof which is my first choice. I just need to find the right person to do it and a hood that fits our budget and doesn't overcrowd our kitchen. Sorry not to be of much help! I will try to find out about the sink though. I can tell you this...it is on wooden cabinets that appear to be fairly old. The surface is great except for some rusting around the holes for faucet stems. When I scrub pots and pans, they leave grey marks. I usually scrub them off with soft scrub. I'm not saying that's the best way to keep it white, it's just what I found to work. I will be in touch!