Extractor Fans - kitchen

    I am having a new kitchen installed at the moment, and the fitter installed a new extractor hood.

    It has an extraction rate of 550cubic.m/h

    The outlet is 6" and supply with the hood is 150mm ducting.

    My builders, due to ease of access have decided to use 4" ducting and a reducer.

    They tell me this will not affect the extraction rate at all, however, I can't see how that can be.

    Anyone knowledgeable about these things and can offer any advice, that would be appreciated.

    Kind regards


    Either way if the unit fails the manufacturer may walk away from any claim. Ask to see the instructions, and if in doubt contact the manufacturer.
    Edited by: "hubcms" 7th Dec 2016

    Why would you want a dead farmer in your kitchen?

    same volume of air will be extracted. velocity in the duct will be higher.maybe slightly noisier but I'd guess this would be fairly negligible

    I don't think they can prove that it will not affect the extraction rate at all. It will most likely be a little lower. However it should still work but with a higher back pressure from the exhaust side. Also the length of time you will run it for will be limited, so it should cope.

    Having said that if you have paying in full to get a job done then they should do it properly and not cut corners just because it is easy for them.

    Original Poster

    Thanks all, you are right about the paying in full and cutting corners, however given the above will let this one pass, there are other issues I'd rather be sorted, so will pick my battles. Sounds like this isn't a battle worth having.

    Thanks again all

    It's a common for a the hole to be smaller which causes the extractor to be noisy. It's caused by the air back pressure. Crazy really as everyone fitting these should have the right size cutter as this was a common problem raised over 10 years ago.

    Are you going to run the extractor at full speed often ?

    Original Poster


    Are you going to run the extractor at full speed often ?

    Post a comment
      Top Discussions
      1. love affairs1223
      2. What's the most impressive 4k / UHD film you have seen at home?1015
      3. Apples new update711
      4. What do you feel like whinging about today?1927348

      See more discussions