Announcement

Collapse
No announcement yet.

kITCHEN EXHAUST FAN

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • kITCHEN EXHAUST FAN

    I'm doing some planning for a kitchen update and have what I think may be a stupid question about an exhaust fan outlet. As a result of furnace and water heater upgrades, there are 2 unused B vents through the roof of the house now and I would like to consider using 1 of them for a kitchen exhaust fan, not a crazy volume unit, just a 200 - 300 CFM fan. It's a 60's bungalow so not airtight. I would propose insulating the duct to the roof vent to reduce condensation.

    Anything else I should look at? Is this not a good idea? Any suggestions would be appreciated.
    The difference between a master and a beginner: The master has failed more times than the beginner has even tried.
  • Thread Continues Below...

  • #2

    Re: kITCHEN EXHAUST FAN

    Peter,

    I suspect your question will generate some debates. For my own education, could you please tell what a B fan is?

    In terms of your project, is your exhaust fan located on an exterior wall? What would be the total length of your conduit for the two scenarios (wall vs roof)? How many elbows?

    Regards,

    J.

    Comment


    • #3

      Re: kITCHEN EXHAUST FAN

      The roof and roof vents were recently replaced on my strata (condo duplex) building. The kitchen fan vents through the roof (as it did before). But now I notice when the wind blows there is a stream of cold air coming down the vent. I now have a piece of plastic held by magnets over the intake at the stove when not in use. I asked at the building center about flappers on the outlet of the range hood or at the roof vent and was told that isn't normally done. My old house where the range hood vented through the wall had a flap where the vent exited. It would rattle a bit in the wind but at least provided some seal against a cold draft.

      Comment


      • #4

        Re: kITCHEN EXHAUST FAN

        Originally posted by Jacques Gagnon View Post
        Peter,

        I suspect your question will generate some debates. For my own education, could you please tell what a B fan is?

        In terms of your project, is your exhaust fan located on an exterior wall? What would be the total length of your conduit for the two scenarios (wall vs roof)? How many elbows?

        Regards,

        J.
        The B vent is one that had been used for a gas appliance 4" diameter.
        The proposed fan will be on an inside wall and, if I use the existing vent, would have 2 45 degree elbows.
        The exhaust fan in the bathroom vents through the soffit. I could do the same thing in the kitchen if necessary.
        The difference between a master and a beginner: The master has failed more times than the beginner has even tried.

        Comment


        • #5

          Re: kITCHEN EXHAUST FAN

          Originally posted by Kayak Jim View Post
          The roof and roof vents were recently replaced on my strata (condo duplex) building. The kitchen fan vents through the roof (as it did before). But now I notice when the wind blows there is a stream of cold air coming down the vent. I now have a piece of plastic held by magnets over the intake at the stove when not in use. I asked at the building center about flappers on the outlet of the range hood or at the roof vent and was told that isn't normally done. My old house where the range hood vented through the wall had a flap where the vent exited. It would rattle a bit in the wind but at least provided some seal against a cold draft.
          Good point. I hadn't considered backdraft as an issue.

          I wonder if a backdraft prevention device could be installed inline?
          The difference between a master and a beginner: The master has failed more times than the beginner has even tried.

          Comment


          • #6

            Re: kITCHEN EXHAUST FAN

            Originally posted by Kayak Jim View Post
            The roof and roof vents were recently replaced on my strata (condo duplex) building. The kitchen fan vents through the roof (as it did before). But now I notice when the wind blows there is a stream of cold air coming down the vent. I now have a piece of plastic held by magnets over the intake at the stove when not in use. I asked at the building center about flappers on the outlet of the range hood or at the roof vent and was told that isn't normally done. My old house where the range hood vented through the wall had a flap where the vent exited. It would rattle a bit in the wind but at least provided some seal against a cold draft.
            Here's what you need Jim. I've used them before and they work well. Don't buy a cheap one -- it will fail.

            Here's another one.
            Last edited by Wally in Calgary; 03-25-2020, 12:35 PM.

            Comment

            • Thread Continues Below...

            • #7

              Re: kITCHEN EXHAUST FAN

              Thanks a lot for that Wally. I'll follow up with the building manager and see if the wrong vents were installed. I'm surprised the guy and my Home Building Ctr didn't identify these as available.

              Comment


              • #8

                Re: kITCHEN EXHAUST FAN

                Peter:

                Looks like Wally found exactly what you need. One concern I had was the backdraft that Jim raised.

                J.

                Comment


                • #9

                  Re: kITCHEN EXHAUST FAN

                  Ditto on Wally's suggestion. Recently changed a similar situation on my parents place and this was the ticket.

                  Comment


                  • #10

                    Re: kITCHEN EXHAUST FAN

                    I never liked the fact they melt the snow and cause Ice build up in winter so had a sht metal shop make me one up with a damper that exhausted 16" above the roof. Where possible I prefer wall exits.

                    Comment


                    • #11

                      Re: kITCHEN EXHAUST FAN

                      Thanks all for the suggestions. I should be able to find something from those recommendations to adapt to the existing roof opening to accommodate the exhaust fan.

                      Thanks for the links, Wally.
                      The difference between a master and a beginner: The master has failed more times than the beginner has even tried.

                      Comment

                      • Thread Continues Below...

                      • #12

                        Re: kITCHEN EXHAUST FAN

                        Before you finalize your purchase check your new fan - I assume this is a range hood fan - but regardless, many of them have built in dampers. You don't want two dampers in the line. You do definitely want the grill screening. Given your temperatures in B.C. I wouldn't think the temp differential in the attic, or wall, or wherever, would be enough to cause any noticeable condensation, particularly given the sporadic use of a kitchen exhaust fan.

                        With a damper at the fan rather then the outside end, you would avoid wind-blown flapping noise.
                        Start slow and wind down gracefully

                        Comment


                        • #13

                          Re: kITCHEN EXHAUST FAN

                          Originally posted by Woodwreck View Post
                          Before you finalize your purchase check your new fan - I assume this is a range hood fan - but regardless, many of them have built in dampers. You don't want two dampers in the line. You do definitely want the grill screening. Given your temperatures in B.C. I wouldn't think the temp differential in the attic, or wall, or wherever, would be enough to cause any noticeable condensation, particularly given the sporadic use of a kitchen exhaust fan.

                          With a damper at the fan rather then the outside end, you would avoid wind-blown flapping noise.
                          Steve:

                          I have a feeling that Peter (the OP) would like to enjoy the BC winters that Jim experiences .

                          Regards,

                          J.
                          smallerstick and like this.

                          Comment


                          • #14

                            Re: kITCHEN EXHAUST FAN

                            Originally posted by Jacques Gagnon View Post

                            Steve:

                            I have a feeling that Peter (the OP) would like to enjoy the BC winters that Jim experiences .

                            Regards,

                            J.
                            LOL You bet I would but life in northern Ontario is still pretty good. Insulation for the ducting here is a given.
                            The difference between a master and a beginner: The master has failed more times than the beginner has even tried.

                            Comment


                            • #15

                              Re: kITCHEN EXHAUST FAN

                              Originally posted by smallerstick View Post

                              LOL You bet I would but life in northern Ontario is still pretty good. Insulation for the ducting here is a given.
                              Peter -- THIS is what I usually use.

                              Comment

                              Working...
                              X