Good shower room fan

[gemshan1]

hi all, we have no outside window in our shower room and the fan is a cheap £20 job!! As you can imagine the walls are running with water after using the shower, could anyone on here recommend a extractor fan that will do the job properly, or am I wasting money buying a more expensive one?
Thanks

 

[stem]

The recommended air flow rate for a bath / shower room is a minimum of 15 litres / second (Building Regulations Part F) so a fan that has that capacity or more should be OK.

The price is not a definitive guide, because it relates also to the quality of the fan as well as its performance. But I would be expecting to pay about £40 for a decent quality basic fan for a bathroom, a bit more if it has a sensor or timer.

Bear in mind too that a fans performance will be greatly reduced if it is connected to more than 2 to 3 metres of ducting, or a duct run that has bends. In which case I would recommend a centrifugal fan that generates a higher pressure than a basic axial fan and can overcome the ductwork losses.

You should also make sure that there is somewhere for replacement air to enter the room, without too much resistance, such as a gap below the door. Ideally air will enter at the opposite side of the room to where it is extracted to get a flow of air across it, although this isn't always physically possible.

 

[gemshan1]

Thanks for that info stem, very much appreciated.

 

[stem]

Warm moist air will condense on a cold surface, so even with good ventilation you will still get some condensation forming whilst showering, especially if the walls are cold, but a good fan should clear it in a short time. One with a timer that keeps it running for a while after you have finished showering would be a good idea. In the winter, heat is also important. the warmer the walls, the less condensation forms on them. Also, warm air carries more moisture, meaning more moisture will be sucked out with the air.

 

[JohnD]

hi all, we have no outside window in our shower room

does the fan go straight through an external wall, or is there a duct?

Is the hole 4 inches/100mm?

is the fan wired to come on with the light switch, and does it currently have a run-on timer?

 

[gemshan1]

Just ordered one of these, if this doesn't do the job I'll shower in the garden cos it rain every b@@dy day lol

 

[foxhole]

For best results the fan should run every time the room is occupied , ceiling mounted sensor is good for this , fan should ideally be sited above shower cubicle with a powerful fan in my shower room we get no condensation anywhere anytime of the year .

 

[JohnD]

the one you have bought is a 4" ducted fan. Typically mounted in the loft to blow through a duct. I don't see the air throughput, but they are often in the region of 240 cu.m/hr, which is about three times the nominal output of the common cheap builder's fan. It should make a big improvement. They are usually quiet enough to run for long periods without being annoying, and use very little electricity.

Yours is quite a cheap one, often sold to people with cannabis plantations in the loft, but if it fails, you can get quite good makes next time that will swap in, but cost more.

As your bathroom has no window, the fan can conveniently be wirired to come on with the light switch.

Does your current fan have a run-on timer? If so, you may find an extra wire. Terminate it safely, you may want to use it if you get another Timer fan in future.