[b]Kitchen ventilation[/b]

Discussion in 'Kitchen Fitters' Talk' started by spingers, Feb 24, 2007.

  1. spingers

    spingers New Member

    Does anyone know where I can get rigid 100mm round ducting 90 degree connectors? I am really struggling to complete my kitchen extraction.
    It seems as though everyone does flat ducting these days but we had a very nice man from Expelair come round and do some working out and he based his maths on 100mm round ducting. I have tried contacting him again but I may have used up all my brownie points so am trying to do it myself.
    It is a long way to the nearest external wall 6.5 meters and as I understand it flexible reduces the air flow considerably more than rigid. To be inline with building regs F1 I need to achieve 30 l/s of extraction which is possible using the instruction the epxelair man gave us.
    I have a very strict bulding inspector to impress so I want to have done everything in my power to answer any further questions,
    I'd appreciate any advice on the subject.
  2. JJH

    JJH Member

    May sound like a silly suggestion, but;

    How about mitering two short pieces of round pipe at 45 degrees . Then solvent weld back together to create the desired 90 deg??? Then its just a case of using 100mm pipe connectors to attach to the extract pipework.....

    Just a thought????
  3. Slimes

    Slimes New Member

    I often use 4" soil pipe to fit an extractor fan- solid length through a cavity wall with wall mounted fan and wall mounted external flap makes the job quick and simple.

    So maybe white pipe and swept bends will sort you out?


  4. STGO

    STGO New Member

    Two excellent replies
  5. kitcheneer

    kitcheneer New Member

    If you are looking for good airflow then you need to be looking at bigger pipe. 120/125mm pipe will flow a LOT more air than 100, not just the bigger cross section (cross section will increase as the square of the radius) but there is proportionally less pipe surface to provide resistance. This is especially important if you are using, as you may need to, corrugated pipe.
    Another thing, tight bends are disastrous to airflow.
  6. spingers

    spingers New Member

    Thanks for all the above replies, very useful.

    next question, anyone bored and want to do it for free;-)


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