I have the 6-burner 36" Bluestar rangetop too.

Yes, you absolutely need a back trim with the Bluestar rangetop. It seals up the back of the rangetop; without it the guts would be hanging out there in your cabinet or against the wall. That could thoeretically be a fire hazard.

Having said that, using a Bluestar rangetop with a downdraft unit is a horrible idea! We have a 42" x 24" 600 cfm hood and it barely keeps up with sauteeing. I fear that you would be setting yourself up for a very smoky, steamy house.

If you really, really can't do overhead venting, perhaps you should choose another rangetop. I believe Viking offers a downdraft unit that is compatible with their 36" rangetop.

I have to echo alku05's concerns. If you have enough down draft cfm's to handle a BS range top, you would likely suck the flames off the burners or at a minimum, impede the burners performance. JMO

I have yet to see a downdraft that can do a decent job of exhausting steam, oil etc.
If you are getting a BS, you must be serious about cooking which means the DD will end being an expensive limitation.

Are you doing a rangetop? Or a full range? Because I believe that the range top (i.e., no oven) do not have the trim, since the trim is for venting the oven, not for venting the burners, which (duh) vent themselves directly.

Thanks for all of the insight, I appreciate it!

We had a 36" Viking 6 burner VGSU drop-in cooktop with a 500CFM interior downdraft pop-up rear vent at our last house. This venting arrangement was barely adequate but we didnÂt have any real issues with it. The cooktop operated fine but simmer quality was non-existent and the igniter went out, like so many others.

The new house has very tall ceilings above the island and no practical way to put in a hood as all of the utilities are in the space above that ceiling (HVAC, water, etc.).
We have however been able to install an Electrolux Icon downdraft vent system with an adjustable exterior 1600 CFM blower (that's more capacity than our Furnace!). I'm sure that will be more than adequate if it comes up out of the countertop high enough.

The issue is that the depth of the Bluestar range top (no oven) appears to be about 26" deep all by itself, which would hang out of a 24" deep cabinet already. Add in the island trim and the downdraft stacked behind it & it's sticking out like 4"!

Thus my question, it sounds like I really should call Bluestar and get their blessing, if possible.

Thanks again to everyone!

Having a Bluestar rangetop installed in a 24" deep cabinet, I can't see how there would possibly be room back there for a downdraft. However, since this is an island, can the downdraft be installed in the cabinet behind the rangetop's base? I still think a downdraft is an awful idea with the Bluestar, but if you're set on it, you're set on it.

This picture does a good job of showing how much the rangetop protrudes. Our columns bump out about 2.5".

Hi alku05,

Thanks for posting the photo of your installation, I've examined it closely before as well.

Yes, I think that you're correct, the downdraft will have to go behind the cabinet (actually in between the front & rear cabinets). I'll have to get all of the pieces and figure out what can go where - after I call Bluestar!

After thinking about it, I'm not so sure that the downdraft is really such a bad idea. We used it on our Viking reasonably well. The vent wouldn't really affect the flame of the burner - because it's covered by the pot or pan you've got on the stove. The vent will really be drawing the fumes from the top of whatever's cooking.

I see from the Bluestar brochure that the trim is really used to vent an oven below, if you've got one so I'm still not clear if I can simply eliminate it in favor of the downdraft. By the way, the thickness of the downdraft (from front- back) is 2-3/4", not as bad as I thought.

Thanks again