On Jan 23, 8:00*am, wrote:
I need to extract 247 cubic metres per hour from my bathroom. I will
be using a 150mm ceiling fan capable of extracting 250 m3/ph. Can you
tell me which ducting system I should use for this? I have a 1.5 metre
run. Currently I have 100mm circular flexible hose already installed,
I intend to use a 150mm – 100mm reducing spigot. Do you think this is
sufficient or should I increase the hose diameter, to system 125 for
example?

If I go larger than 100mm hose I will need to use rectangular flexible
hose. It seems that the only rectangular flexible hose options are
options available are “system 125” (150mm x 70mm) or “System
204” (204mm x 60mm). *System 150 (180mm x 90mm) does not seem to be
available as rectangular flexible hose. Is this correct and what do
you recommend?

Many thanks for you help

Is heat forced air, try having fan run 24-7 for now. Spray mold with
laundry bleach. If forced air maybe you need better supply and
returns. There are alot of other possibilities like overhumidifying
your home with a humidifier that you have not gone into. In winter
ducting outside is a waste unless its new tight construction and you
are to humid. There is alot more to the overall picture nobody knows
about, is this a Steam Room.