Questions and Answers for Broan-NuTone Roof Cap with Built-In Damper for 6 in. Round Duct in Black

A:  Thank you for your question on model 634M. This roof cap is designed for pitched roof installation only.

A:  Thank you for your question regarding the 634M roof cap. If the range hood requires a 7" vertical ducting, we would not recommend reducing the duct size. We do not provide data performance on a duct size that is not recommended on the hood. Both performance and sound will be affected.

A:  I believe it would be fine. A 6 in. dia duct X 8 ft. long has a cross sectional area of about 28 sq. in. and is rated at about 3900 CFM. This roof cap has a 4 X 10 in. outlet which is 40 in. sq. which is larger. If your duct length is longer than 8 ft., the 3900 CFM would be reduced, but it should still handle 600 CFM easily.

A:  I previously answered the question saying it should be fine. I forgot to say that for a range hood, you should use a metal duct. Aluminum is supposed to be okay.

A:  Hi natalie, Thank you for your inquiry on the 634M Roof Cap. Our Technical Support Team would recommend the model 437. That unit can safely be used with up to 1200 CFM.

A:  If the hood has a 6" round outlet or the equivalent in square or rectangular, 27 1/4 sq. in., it should work. If the hood has a larger outlet, you should probably use a larger size vent line and cap.The cross section of the vent cap outlet is somewhat less than the 27 1/4 sq. in cross section of the 6" round inlet.

A:  Hi Robo, Thank you for your question on the model 634M roof cap. This model will use a gravity damper.

A:  This is a gravity to close damper. A spring would require a lot of fan pressure which most bathroom vent fans or kitchen exhaust fans do not have. I have multiple dampers in use for both of these locations 

A:  Gravity style

A:  Yes. Rigid duct can be used. If you have further technical or installation questions, please contact our Broan-NuTone Technical Support Department at 1-888-336-6151 between 8:30 AM and 7:00 PM (EST) Monday-Friday.

A:  Yes, you can attach 6" rigid ducting to it, but attach the ducting before you install the roof cap in the roof. Mine is installed to vent an exhaust hood fan over a gas stove and I have rigid ducting attached to it.

A:  You may want to review the installation instructions that are provided on the Home Depot site. The 634 can be secured using roofing cement to seal top and sides of roof cap. Seal all nail heads with roof cement as well. If you have additional questions, please contact our Broan-NuTone Technical Support Department at 1-800-637-1453 between 7:30 AM and 6:00 PM (CST) Monday-Friday.

A:  I really can't answer your question as the roofing crew put it on. However, I'm sure it wouldn't hurt to apply some kind of sealant. Sorry I can't offer more help.

A:  It comes with complete instructions for installation and those instructions recommend rubber roofing cement, if my memory is correct. There’s a link to the installation instructions on the product page; https://images.homedepot-static.com/catalog/pdfImages/c9/c997765c-3987-4bbf-a5f6-b60e78b49108.pdf

A:  No. This is designed for a roof. The door flap may not close properly. If you have a unit that is exhausting though a wall, we recommend using the wall caps. If you have further technical or installation questions, please contact our NuTone Technical Support Department at 1-888-336-6151 between 8:30 AM and 7:00 PM (EST) Monday-Friday.

A:  yes , normal

A:  Never had this problem since I installed the roof cap 2 years ago even though the length of the duct is less than 6 ft. The issue may be related to the type of ducting used. Am using 6" insulated flex duct. I can hear when it rains real hard but it's a muffled sound and does not disrupt our conversation in any way.

A:  The roof cap can make noise. That is normal, however, you may want to reach out to our Broan Technical Support Department at 800-637-1453. They are available M-F, 8:00am - 6:00pm CST.