Kitchen Exhaust and Make-up Air in One Range Hood
rockies63
| Posted in General Questions on
Has anyone heard of or done this method before? It was designed by NS Builders out of Boston in tandem with Ross Trethewey, son of Richard Trethewey from This Old House.
Performance test:
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Replies
It is a neat and clean install option. It feels like it should work well, but it actually doesn't:
https://s3.amazonaws.com/greenbuildingadvisor.s3.tauntoncloud.com/app/uploads/2020/01/16133334/Optimizing-Makeup-Air.pdf
Seems to be the best option is make up air behind the stove, otherwise somewhere in the room.
I disagree with one thing, to me it immediately looks like it won't work. Why would the incoming air drop down to the cook surface instead of getting sucked right back out? They seem to be overestimating the force of gravity on that air, or maybe it's just wishful thinking. It actually irks me how many credulous commenters on the video are praising this design and build, which is not only a massive waste of time and resources, it's encouraging more to follow in their footsteps.
Unfortunately there is a lot of this type of information out there.
By directly sucking the make up air back out, it also means there is no cost for heating it up. It is about as green and efficient of a design as you can do with a 1200CFM hood.
The good news is that this setup is a great way to get a 1200CFM hood to work as well as a 200CFM unit.
The first giveaway that this isn't well designed is that the hood is the same width as the range. And the actual capture area is even smaller, given the 'hood within a hood' design. Effluent expands as it goes away from the source, so this won't capture it all.
Supplying make up air closer to the exhaust than the effluent source should be an obviously silly thing to do, but evidently it's not. The make up air is just going to short circuit into the exhaust. In fact, the "performance test" shows exactly that!
NS Builders does a lot of meticulous, well crafted work. Unfortunately, it's often way too much form over function for my taste.
The best source of residential range hood information I've found is on the Houzz (formerly Garden Web) forums, from a user who goes by 'kaseki': https://www.houzz.com/activities/user/kaseki
Their posts are an absolute wealth of information.