chilkoot, I feel for you,....I too am stuck with a downdraft because of the way my cooktop is situated in an island with no possible way to put REAL ventilation into my kitchen. I have a kitchenaid downdraft, and I'm sorry I do not know what model number it is. It's about 7 years old and has always been 95% useless.

My advice to anyone who is stuck having to get a downdraft is to try and choose the one with the highest rise and the strongest pull. Unless I cook in a low skillet on the back burners, everything just goes straight up to the ceiling. (which now needs to be painted) If I cook in a low skillet on the front burners, it doesn't pull it in at all.

Also, take a real good look to see if the downdraft is CLEANABLE. Mine is impossible to get clean, no matter how hard I try. There is no way to get to all of the grease.
( Can you tell I don't like my downdraft?? :)

It also sucks some of your heat from back burners towards it, lowering the heat. I have gas and the flames go towards it, but maybe that wouldn't be a problem with induction. On the other hand, heat is heat?

I seldom use the vent unless I'm going to blast something that will set off the alarm...and when I do, I have to use the back burners with a LOW sided skillet.
I know that's bad, especially with gas, but it just doesn't work...not to mention that it's unbearably NOISY!

Unfortunately, my largest/hottest burner is one of the front burners, too far from downdraft vent, so I am not able to utilize that burner to it's capacity for frying, searing, etc. due to the poor ventilation.

thanks monaw. I'm sorry yours didn't work out either. The thermador has a 14" rise which is a lot taller than the Faber which had about an 8" rise. At the time I didn't pay much attention since everyone assured me it would be better than my old Jennair with central downdraft[no rise]. Incidentally I'd always found that to be adequate though they may have changed since 1980 when I put it in!
Does anyone out there have the Thermador 14"rise [masterpiece series>?...and if so internal,inline or external blower? I'd appreciate your thoughts.

I just bought the KA KIRD801VSS. It hasn't been installed yet so I can't comment on this model for another two weeks. But it is nice looking-and sturdy. The top cap has a nicer finish on it than the Bosch I saw. I had plugged in an older KA model that only rose 9" but it was reasonably quiet and drew air well. I had asked my appliance dealer if the Thermador was any quieter than the KA. His reply was that most of the noise is not from the blower itself (unless there is something wrong with it) but it's from the air being sucked over the filters.

As for location of the blower, the way these vents are assembled, you don't gain any space by having the blower located elsewhere. There is a big metal box with exhaust pipe whether the blower is located inside the box or inline or external. If the blower is inline or externally located, it needs to be bigger CFM because fans are more effecient at pushing air than drawing it. I don't know if a bigger blower uses noticeably more energy.

For me, the KA model which comes with an internal blower was much cheaper than Bosch or Thermador which requires blower to be purchased separately.

I just bought the KitchenAid as well. It hasn't been installed yet either but I had a Thermador previously and in this reno looked for the downdraft with the highest rise. The Kitchen Aid met the requirement - I also went with the KitchenAid gas cooktop (30" 5 burner) because I was looking for one where the gas rings are lower. My Thermador with the high burners and low rise vent didn't work! I'm hoping this version works better - I too am stuck with downdraft. I'll let you know in a few weeks!

Thanks Riverspot and slo girl.I'm glad you think the kitchenaid looks good ,I couldn't really tell from the photosI hope it works for you.The Kitchenaid would be better for me also because it can be reversemounted so I would still get decent drawerspace under my cooktop. It's also cheaper than the Thermador. Monaw how tall is your Kitchenaid downdraft? I'm hoping its an earlier model and things have improved....but as my granny used to say "if wishes were horses then beggars would ride.....hmm. Its frustrating to put in an expensive fan if it doesn't work well.

I was originally planning to use downdraft, and did quite a bit of research on them. One thing that was a big issue for me was how much space they took up under the cooktop, since I wanted to have drawers. I think Bosch & KA were both on my list for that reason, but I can't be certain.

chilkoot, My Kitchenaid downdraft is only 8 1/2 inches high. No wonder it doesn't work! Hopefully they've improved.

Come back and tell us what you chose and how it works! I'd like to replace mine if I have enough room down below...

Thanks Monaw. They both have the same venting so I'm going to hold off till the last minute but will likely get the new Kitchenaid which is a lot cheaper than the Thermador,and is still 131/2" tall. I saw the Thermador today and was unimpressed with the looks. Perhaps because it was a floor model it had been badly installed but it was all scratched at the base from going up and down.
I'll report back to you what I think ...but it will likely be September before I'm in and cooking much with it.
Thanks everyone for your help.
If Riverspots or slogirl are techno whizzes could they post a phot so I could see what the top looks like it?
I have to order it sight unseen.