http://www.ventahood.com/images/docs/fxr9%20under%20cabinet%20range%20hood%20specifications.pdf Both fori and heimert make a good point. Most people talking about VAH over Bluestars are interested in major smoke ejecting. The undercabinet ones are of a tamer depth 19-21 from my quick look. I chimed in because I am about to buy a 30x27 inch deep hood (probably out of consumer-gotta-have-it paranoia) for a small bluestar--everyboody seems to say go for the coverage if one can afford the space for the extra canopy which actually does make functional sense especially if you are in an apt. space as I am. (I'm definitely not adding anything new here, but trying to save you having to pick through all the venting threads)

Start detective work. Begin with the fan motor itself. Is it balanced, or does it wobble? then look at the housing. Caulk and insulate anything that moves when it's not supposed to. Then the duct cover....and keep going. You may not eliminate noise, but if you eliminate every little bit of noise from every source, you end up making a big difference overall. One of the bigger possible culprits besides the motor itself is the duct run itself. It should be secured to studs and have rubber isolation strips between it and the studs. It should be joined together fully with mastic at every joint. It should have an insulation blanket around it, and it should be encased in a drywall chase which has either foam or blown in cellulose.

Hi, We're looking at getting an extractor hood for our in island 30" cooktop (max output 52,000 BTU). I'm looking for the following specs if anyone has come across such models in their search, suggestions would be much appreciated! 1 - 500 CFM at least 2 - Low profile (glass hood with SS telescopic duct to fit 8ft ceiling 3 - External venting 4 - Low noise 5- A non return flap to avoid heating/cooling loss when fan not in use Many Thanks!

In order to begin to understand it, you would need to buy ANSI Z21.1 for about $650. There is some very technical engineering, even though it doesn't look like it, in the ventilation between walls of the oven and cooktop sides that ensures that the cabinets up against the range will not get hotter than 194°F. If you block the airflow by lowering the range (some people try modifying the feet for thin countertops that make them less than 36" tall), or putting ducts in for MUA, the outside wall of the range will get hotter. If you force that much extra air through the range, (push or pull) you change the way the gas burns, and create CO problems. Even if you can adjust the air shutters to compensate, you would then have to turn on the entire system just to make a pot of tea, in order to get enough air to get a clean burn. With holes in the floor or back wall, the natural draft intended/engineered to cool the outer walls of the range can be disrupted or diverted, leaving the heat to build up around the range - nothing to do with heat in other areas of the home. What can't tolerate more heat than the wood cabinets around the range? Another separate reason for no holes is the possibility of a gas leak. How much gas do you think that duct will hold, just waiting for someone to create a spark? The testing standards do not say no holes "unless someone thinks of some unusual excuse".