You need a proper hood. There won't be space anyway for a downdraft behind that cooktop.

This cooktop belongs along the wall, not in the island. That way you can exhaust it, and also cooktops in an island are impractical (see threads on why on the Kitchens Forum).

I am always surprised how people are willing to spend a lot for the cooktop with the highest btus they can find, but don't want to contemplate good ventilation for it.

So you're in the no island cooktop camp. I get it. Plenty of people get cooktops in islands and love them. Money is not the issue with ventilation. Constraints are the issue. I'm trying to get the best cooktop for my space. My research says blue star is the best. If I can't make it work I'll find something else. Anyone actually put one of these in an island?

It's not just that a cooktop in an island is poor kitchen design, nor that downdraft exhaust is a bad idea (because it both goes against the laws of physics (smoke and grease go up, not down), and because it will pull on the gas flames of the burners). Nope, those are not all the issues. On top of those things is that you have chosen a Bluestar open-burner cooktop for a downdraft arrangement. Bluestar cooktops are deeper than others. How deep is your island - is it deep enough to accommodate a Bluestar cooktop depth plus the added depth of the best downdraft you can find? And, because the burners are open, you are really pulling on those open flames with a downdraft.

Call Bluestar and see what they say. Report back.

The appliance store is already checking with BlueStar. In the meantime I was checking this board to see if anyone had done it before. I have not purchased anything yet. I'm still researching. So even if you get your "I told you so" moment and then I just buy a Bosch. It doesn't matter.

It's too bad too as most people are helpful without the sarcasm or attitude.

I am sorry that it read as sarcastic. I did not intend for even one word to be sarcastic. My attitude was unduly harsh on my first post, yes that is true. I get frustrated sometimes.

My second post was intended as informational (depth of island needed for Bluestar cooktop and downdraft, and the issue of pulling on open burner flames). And I really want to know what Bluestar says - again, no sarcasm, I truly want to know.

"Greg

I know these things throw off some serious heat so I want to make sure I get it right! "

Sahmmy is just trying to help you with this part of your request, which is the most important part of your request.

As far as not using proper ventilation, there have been a few people use a recirculating hood in tiny New York apartments with a BS range but it is far from ideal. Just because you can do something or someone else has done something doesn't make it a good thing to do. Part of it might depend on the cooking you do. If you use relatively low heat and not too much smoke, you might be ok but why would you be getting high BTU burners --unless you just want the look? If you don't mind the heat, grease and smoke wafting then you are good to go.

Having said all that, here is an article that might be helpful to you.

http://blog.yaleappliance.com/bid/97651/Most-Powerful-Strongest-Downdraft-Ventilation-Reviews-Ratings

Have you looked at induction? At least you would have a little less waste heat but if you use high heat in cooking, you would still have grease and smoke.

Thank you. Lots of good information on that site.