On 13 Jan 2006 09:10:09 -0800, "Sheldon" > wrote:

>
>Chuck wrote:
>> Going to have to install range hood with outside exhaust (through the
>> roof) this weekend...
>
>Why through the roof, why would you want to cut a big hole in your nice
>brand new roof? If possible you're always better off with a
>residential exhaust exiting through a side wall with the ductwork
>aiming downward. My exhaust duct goes up through a kitchen cabinet and
>into the attic where it travels horizontally about eight feet and exits
>downward through the soffit... this arrangement also makes it easy for
>me to maintain the system myself, I can easily remove all the ductwok
>from inside the attic and take it outside to clean if necessary.
>Ductwork exiting a peaked roof tends to suffer from down droughts as
>even a slight breeze is amplified by the venturi effect as it travels
>over a pitched roof. For such a system to work properly you'd need a
>vent pipe that extends at least three feet higher than the roof ridge,
>very ugly. Those flush mount mushroom looking thingies don't work very
>well on many counts, the exiting exhaust grease will stain the roof
>too, badly... within a year you'll have a big ugli stain on your nice
>new roof, and everytime it rains that stain will expand and also run
>down to the eves... this won't look pretty. You don't want to place
>any extra holes in a roof, just another place for a leak to develop.

I've not seen the soffit fixture... Did you use a "wall" fixture there
or do they make one just for exiting soffit?... I prefer this
option...
Chuck (in SC)