I got this extra-wide (42") range hood from a Sears store that sells refurbished appliances. It's dented right in front, but it was cheap, and it has twice the flow rate of a standard unit. There were knock-outs for a standard-sized (10"x3.25") rectangular vent in the top and back. I opted for the top and adapted it to 6" round pipe.
![](http://i1285.photobucket.com/albums/a591/crt0/c42f7b6489e76b01605205b4ccba6fe5.jpg)
In the next photo, you can see the round pipe running from the hood through the joist bay to the rim joist. I really ought to insulate that pipe.
![](http://i1285.photobucket.com/albums/a591/crt0/34f9f75be55bcf54c597af1fff40d8f3.jpg)
Here's the vent assembly on the outside of the the house.
![](http://i1285.photobucket.com/albums/a591/crt0/0f4972c74d59f5d4ce7ac1370e454441.jpg)
To put that in, I had to cut a hole in the side of the house. A friend with a hammer drill came over to help me (thanks, Tom).
![](http://i1285.photobucket.com/albums/a591/crt0/a5c72e7a9ad1daefc61f6e9c02babf93.jpg)
Keeping the fan on full blast during the boil keeps condensation and humidity in check. It doesn't completely eliminate the smell of boiling wort in the house, but it's a considerable improvement. I keep the fan on low when working with cooled wort or yeast, thinking the resulting updraft will prevent bacteria-laden dust from landing.