I am installing a new range and vent hood in my new kitchen addition, and I wanted to know the best way to cap and run the vent. I am running a 7″ duct approximately 4 ft straight up through a 4:12 pitched roof. How high up does my vent need to go? What kind of cap do I need? The range & hood are Viking. I live in Northern CA.
On a related note, is there a good web resource for building codes? I’ts crazy to me that the code books are hundreds of dollars, yet I am required to follow them. Yes I know I can go to the library, but it’s no where near as convenient as the web.
thanks!
Replies
I go to my HVAC supplier/sub for the range hood roof vents. They generally have them in stock .
What dovetail said. There isn't much for code requirements on range vents, really it's more just common sense. If you were in snow country you'd want to keep the vent away from the "ice dam area" and off very low-pitched roofs. You also want the shortest runs you can get, which it sounds like you have. Go for it.
Are you under the IRC? The book is about $70. Well worth it...
As far as your vent goes, run it a few feet above the roof, install a roof jack, storm collar, and rain cap and call it good. This is not a flue or chimney--I don't believe there is a code-required height. Good waterproofing should be the main driver.
If I'm not mistaken, the code prohibits the use of corrugated duct between the range hood and exterior vent (something about accumulating grease deposits I think). That's the only restriction that I'm aware of in residential applications. Then again, it could just be a local code here in my area.
I always use the 28-gauge galv pipe that's smooth. Corrugated makes sense for almost nothing to me.