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