I'm really not sure if you'll notice the difference since the external would be so close, but my guess is it will be a little quieter for two reasons: (1) I've heard other people complain about the noise level of "Best by Broan", and (2)The 900 CFM blower when operated at low to mid speeds will probably make less noise that the Broan at the same CFM. It's just a guess. I'd be interested to hear your own conclusion after you try it if you choose to do so.

I also have a bluestar 36, and I have a 600 CFM internal blower hood. I pretty much always run it on low unless stir frying or searing meat or something is burning, then I put it on high. My rule of thumb is if the smoke detector goes on, you need more CFMs ;-)

You have a 99k BTU range?

You need at least a 1000 cfm blower.

A 1200 cfm blower at 500 cfm is going to much quiter than a 500 cfm blower at full speed or 500 cfm.

Mounting the blower outside directly on the wall will reduce noise but not by much.

You also need a 10" duct. Pulling all that air through a small duct will cause lots of noise.

Also, if you live in the North half of the US and have a relatively new house or renovated air tight older house you should consider make-up air. To make up for the air being sucked out by the blower.So as not to cuase a vacuum pulling in CO2 from your heater/furnace.

If you live in the Sourthern half you could always leave a kitchen window open.It should never be so cold when you are cooking a full meal. Lighting one burner for a midnight snack does not require blower at full CFM LOL.

Complicated? Such is life with a powerful pro-style range.

Thanks for the feedback. deeageaux, I would vent it out the top into a 10" round duct. I would get probably about a foot of straight duct before the right angle. I have to fit things into the space I have... Until I win the lottery and then I can bend things to my will... bwahahaha, ehem, excuse me...

dredpir8 - I just wanted to let you know your last post (bwahahaha) made me smile....and giggle to myself. Its been a dull day and I needed that! Good luck with your renovation. I purchased a 900 cfm Wolf internal hood and hope it will be quiet enough. Right now my downdraft hood is so loud that I would rather have the fire alarm go off than to turn it on.

motherof3

I have a question regarding make-up air.

I'm trying to avoid the $2,000 estimated cost provided to me for having a make-up air unit. I live in The Rockies, at elevation, so for six months of the year keeping a window open is not problem. For the other six months, I plan to just open a window in the mud room which is adjacent to the kitchen separated by a 34" door-less "door way", but in a corner of house (thus won't make the house so cold).

If I just open such a window by a few inches (and yes, I know I must never forget to do it) will it be sufficient?

Thanks!

I'm currently struggling to get our Broan vent hood with external motor installed in our kitchen. It's going to require some custom duct work which is holding us up. Just wanted to let you know how very very BIG that outside motor is! It's huge. We were initially going to vent it straight out to the outside wall, but the motor was so enormous and we couldn't make it fit on the outer wall due to an overhanging eave and a concave corner. So now we're trying to vent it out the roof just to accommodate the huge motor. The actual dimensions of the motor are about 27" long, 18" wide and 10" deep.

canyonhome - opening a window should work but the other questions are how airtight your house is and how many CFMs is your hood. Generally you can get by with 600 CFMs without makeup air but certain states up north require makeup air with any hood over 300 CFMs. You need to check code in your area and evaluate what works best in your situation.

It is just plain silly to buy a blower based solely on the maximum BTU of your range. Buy the blower size that meets the needs of how you cook. Do you typically use all your burners on high? The 100-CFM-per-10000-BTU rule of thumb has led many people to greatly over-ventilate, and to require makeup air, or deal with the potentially dangerous lack of it.

I favor a more moderate approach to choosing CFM, and suggest putting more emphasis on hood size, shape and position.

W, thanks for the post. I'm going with a 1200cfm with external blower. I'm in UT, so I'll have to ask my GC.

BTW, before you say "Whoa, 1200cfm, he must have merely used the 100-per-1000 rule", we went with that because we'll do inside grilling during winter and my primary cooking will be using the wok on the 22,000 BS burner. :)

Understood.

Indoor grilling needs a *lot* of ventilation.

Don't forget to open a window to help with the makeup air.