Help me suck harder!

March 30, 2008 12:28 PM

How do I increase the sucking power of my kitchen vent?

I have a GE Advantium over the range microwave/hood. The 300cfm vent is vented straight out the back wall outside. The run is about 8" total.
The blower is far from adequate for my cooking style. I need some serious suction.

Is it possible to retrofit something on the outside of the house where the rectangular vent comes through that I can use THROUGH the existing microwave hood that will be much stronger?

I don't want to add an additional vent or anything behind the range since the wall is all tile and would look stupid. I'd rather improve the "hood" that I currently have.

Please help!

posted by Thrillhouse to home & garden (9 comments total)

This external mount fan advertises 445 cfm. I don't see why you couldn't remove the inner fan on your range hood and mount that one on the outside - A good HVAC specialist or even a general handyman could likely do the job if you're not comfortable doing it yourself.

There are likely many other brands/varieties of external mount fans - that was just the one that came up first in google. You may even want to look into some commercial grade stuff.
posted by davey_darling at 12:51 PM on March 30, 2008

Do you think 445 will be enough? Today I seared a roast and filled the house with so much smoke in less than 5 minutes (with my vent on) that I set up smoke alarms on THREE floors.

Thats a good start, though, thanks.
posted by Thrillhouse at 1:08 PM on March 30, 2008

Are you sure that the range hood isn't blocked in some way? Have you been outside to check the airflow while the hood is on? Are there removable filters on your hood that can be cleaned? Are you absolutely sure that the hood isn't recirculating rather than venting?

It seems to me that you shouldn't be having this much of a problem with your existing setup..
posted by davey_darling at 1:17 PM on March 30, 2008

Oh its blowing all right. Outside you can feel the airflow. I've taken out the filters so thats not the issue. I thought it would be sufficient, too, but it seems to happen to a lot of people I know. You can feel the suction on the inside but the smoke just goes up the front of the microwave and into the house...
I don't get it.
posted by Thrillhouse at 1:31 PM on March 30, 2008

Before adding a stronger fan you might also want to investigate whether there's enough make-up air coming in. If your house is relatively tight and the windows are closed this could be the limiting factor, rather than the strength of the fan. You can easily determine if this is a problem by observing whether the hood ventilates better with a nearby window open.
posted by RogerB at 1:36 PM on March 30, 2008

Yeah, I tried that... doesn't seem to help.... Maybe SLIGHTLY. I have a slider nearby that I open all the way to see if it makes a difference and its barely noticable.
posted by Thrillhouse at 1:45 PM on March 30, 2008

You might consider tuning down the smoke production; it sounds like you're producing more than normal or necessary. Browning a roast -- slow it down a tad. Or do it under a broiler (convection broil if you have it) -- works better than pan-frying. If you've taken the filters right out, whatever fat-droplet-laden air is exiting the vent is now laying down a coating of grease on the inside of the duct, which is how restaurants end up with grease fires.
posted by beagle at 2:09 PM on March 30, 2008

Sorry to say it, but I'd say your cooking style may make this hard to overcome. Searing generates a whole lot of smoke, and you have a better-than-crappy-but-not-especially-great hood. I have hood that's rated for 600 cfm, but the only way I can sear steaks (on an iron griddle that's been heating for several minutes, thrust under a hot broiler immediately after the steaks are applied) without making the whole house hazy is to set a box fan in an adjacent window. Even if you improve the existing hood, you may have to look at alternative solutions when you're doing especially smoky cooking.

What size is the vent that comes through the outside wall? Hopefully it's 6" in diameter, which is what I'd guess your hood is designed for. If the installer reduced it to 4" so they could use a more easily available wall cap, then that would be a big part of the problem right there. In any case, the pipe size is likely to be a bottleneck that will restrict what you can do with the existing setup. If the pipe is on the small side, then no blower in the world can shove enough air through it to make it perform the way you want.
posted by jon1270 at 4:10 PM on March 30, 2008

4HP Briggs and Stratton oughta do the trick. but seriously, sounds like you need to replace your vent and go industrial. one problem might be related to pressure in the house. the fan imposes negative pressure and it will start to loose efficiency. open a window to equalize the pressure and allow for easier flow.
posted by spish at 8:37 PM on March 30, 2008