GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Venting range hood under covered open-walled porch?

corkydork | Posted in General Questions on

Hey all,
I’m doing my obsessive research mode about venting before our hvac is installed next week and I’m having trouble making a final decision. We have an off-grid house, single pitch roof with a vaulted ceiling. Our kitchen abuts an exterior wall and this wall is under a covered porch (see plans). I want to vent a range hood and it’s most efficient/simplest directly through the back wall, but since that’s under a covered (open walled) porch it will introduce moisture up to the roof assembly through the 2″ roof vent which starts back there. Do you think it would be ok if the range hood exhaust terminates 4 feet below the roof vent under this long overhang?

The other option would be to go up through the roof trusses to side wall, which decreases efficiency of fan with the long run and takes 7″ of insulation out of our roof along the vent pipe. A last option would be to install a low watt wall mounted ERV behind stove instead -which we can always do but I’d like to try a range hood first (ERV complicated and expensive). We get insulation soon, so now is the time to run the exhaust pipes through roof trusses if I’m ever going to do this. It would be so much simper through back wall with the covered porch. 

Thank you!

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. Expert Member


    The answer is - who knows? There are so many factors that may tip it one way or the 0ther. In those circumstances it's probably best to err the side of caution. Can you run a bulkhead above the cabinets t0 the sidewall, or incorporate a chase into the top of the cabinets?

  2. corkydork | | #2

    Hey Malcom, thanks for your considerate answer. I considered a long cabinet run but there won’t be cabinets all the way to the side wall -the open space turns into a living room/dining area. I suppose I could make a custom shelf or bulkhead on the top of the wall to hide it, but I’m always thinking about possibility of remodels...I can’t have everything! Hiding it inside does seem like the best option. I could also vent out back at first and monitor. There is a very good breeze back there.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |