Increasing the cfm's on a downdraft blower is like racing you engine in neutral. The downdraft plenum (where the air is drawn in) is really only capable of handling about 600 cfm any increase in blower power will just add noise level. You are not using a Grill (BBQ) so 600 is more than adequate for 15 ft plus an elbow

Interesting info. They offer a 600 and 1000cfm inline motors. Is the 1000 needed only if you have a long run or multiple angles?

Daven,

You did not mention which model of the Thermador downdraft? I can tell that the best scenario is to get the highest rising height possible, and to get a remote fan unit (external to the residence). Buy the best one or you will regret it later. Downdrafts are simply no match for hoods so the better the specs regarding the one you are purchasing the happier you will in the long run. The Thermador Cook 'N' Vent® System downdraft models have a full fourteen (14) inches of riseÂour current Dacor downdraft only has an eight (8) rise; eight inches is not adequate as it pulls the burner flames horizontally when on high, and simply does not evacuate flumes properly when set on low speed; medium fan speed is a mixed blessing for us.

I had a similar question. I have a dacor downdraft 36" to go w/ my 36" dacor cooktop. The owners manual says you can use either the 1000cfm or the 1600cfm. How do I know which to use? My ducting will go straight down, make one turn and then go about 8 feet straight outside.

daven, Im with you, I can usually find answers to my questions by searching here and online, but this one has me stumped. There seem to be a lot of varying opinions. Im hoping it's the 1000cfm cause it costs a lot less. LOL

I don't know what to tell you, mrs. andrews. I just bought one with the 1000cfm remote inline blower and called Dacor because I had three less-than-90 degree turns and a 15-foot run. They said that was the limit before effectiveness dropped.

The remote blower is making noise now under my crawlspace, vented through the foundation under my covered porch. It is amazingly quiet in my kitchen now. I hear it humming, but it's far away.

I find I'm using it a lot more due to its lack of jet-engine noise, so it's already more effective than my previous hood.

We hardly fry anything anymore, just occasional sauteing, so I felt I'd be OK with 1000cfms. Dacor was very helpful, 'tho. Why don't you try calling them with your question? Don't call Customer Service...call Service/Support.

I'm planning on the 14 inch rise unit. I saw a post recommending fantech inline blowers with their silencer sleeve: http://www.fantech.net/fkd.htm. Pricing is lower than the name brand units but I need to call the company and check compatability.

Currently, I have 6" ducting so moving to one of these would require new 10" ducting. I only have a 6" exit vent in the foundation. If I transitioned to this I'm afraid that the back pressure may be too great?

We have had the Dacor Epicure cooktop (ESG366sch) and downdraft and the 1000cfm remote blower for 3 years. They're great. Our run is about 12 feet with one right angle and it's mounted outside my house. Daven check with Dacor because the inline motor is only for certain installation conditions and wasn't recommended for mine.

Maybe fahrenheit has a different model. Our Dacor vent rises 10 inches and it does not pull the flames at all. Downdraft model ERV36, Blower REMP3.

The 1000 cfm is perfect for our installation. My husband initially wanted the larger 1600 cfm unit but we didn't have enough room to mount it outside the house.

Does the owner's manual for your unit give a recommendation for the downdraft and cfm's?

Pamela- thanks for the suggestion to call dacor service/support rather than cust. service. great idea

Daven, thanks for the info. about the less expensive possible option. I'll ask about compatibility for that one too

McMann- The owners manual states that it can be used with the 1000cfm or the 1600cfm and doesn't give any details about how to choose between those two. Real helpful! LOL

Wow, I just called Dacor service/support and the guy I spoke with, Ed, was very helpful. He said there is a formula you can use. For every 10,000 btu's you need 100cfm. Im sure you have to take distance and turns into account also though. Then I told him I was going 8 feet with 1 90 degree angle and he said the 1000cfm would be more than sufficient.

Fantech's website had some useful info. on it also. They have a pdf file on planning your kitchen venthilation.Also, their price on the blower I need was only about $50 less than Dacor's so I think I'll just go with Dacor.