Shower Fans

[blondemoment]

I don't think our shower fan/light is powerful enough and think we should upgrade, my husband however says it makes no difference and all showers get mouldy, but ours is mouldy on the ceiling and I think we should have a more powerful fan and vent it outside not just into the loft!!! Views please

 

[SLIPSHOD & SLAPDASH]

Quite right, most people dont realise you need air to get in , window vent , gap under the door etc

 

[ProDave]

If it's mouldy on the ceiling then the first thing to look at is the level of insulation in the loft. almost certainly there is not enough and the ceiling is cold and water condenses. 

If you don't do the whole loft, at least improve the insulation above the shower room.

You can check if the fan is working by seeing if it has enough suck so suck and hold a sheet of A4 paper against it.  What sort of fan, i.e in the wall, in the ceiling, and if in the ceiling is there a long length of flexible ducting? that is notorious for filling with condensation and blocking the flow.

We have 300mm of loft insulation and not a spec of condensation or mould even if we don't turn the fan on.

 

[Murdoch]

Did you write its venting into the loft then that is the first problem as the hot air will turn into moisture and then the ceiling will get wet from above.

Also, does the fan have an over run timer? This is important as you need to extract the hot air/moisture for a while after you have finished in the shower.

Hope this helps.

 

[Blue Duck]

It vents into the loft!

should go outside or your gonna have more expensive problems!

also you say fan/light it's not one of those horrible things from wickes is it?

Not all showers get mouldy.

 

[NozSpark]

Definately vent it to outside either through the soffits or through a tile vent or you could cause some very expensive problems to your roof.

As for those shower light/vents.... the extractor fans in those are IMHO only just strong enough to meet the minimum requirements of the building regs,,, I would never recommend them... in fact I've just replaced the fan unit on one for a centrifugal fan which has at least twice the extraction rate (if not three times as much).

As others have said, condensation is formed when warm moist air hits a cold surface so make sure that your loft (above) is well insulated, make sure that air can get into the room underneath the door and make sure that you have an extractor fan with timer over run and set it to at least 15mins.....

I know that these extractor fans make some noise, but it can be reduced if its installed off the roof trusses and not on the ceiling joists.

 

[SPECIAL LOCATION]

I don't think our shower fan/light is powerful enough and think we should upgrade, my husband however says it makes no difference and all showers get mouldy, but ours is mouldy on the ceiling and I think we should have a more powerful fan and vent it outside not just into the loft!!! Views please

Your husband is wrong!!

The strength of extractor fans varies considerably...

And the length of the ducting that the fan has to move air though has significant effect as well..

Just as a quick illustration.. consider one of those "typical fan & light arangments"..

http://www.screwfix.com/p/manrose-in-line-led-shower-light-fan-kit-bright-chrome-mm/45818

Have a look at the extraction rate.. "86m3 per hour"...

Whereas:-

http://www.screwfix.com/p/manrose-mf100-w-100mm-mixed-flow-fan/26867

can move "245m3 per hour"!

around 2.8 times as much air volume can be moved in the same amount of time...

BUT..

as has been pointed out no mater what size of fan is used..

YOU MUST HAVE SUFFICIENT AIR COMING IN TO THE ROOM AS WHAT YOU WANT TO EXTRACT OUT.. 

i.e.

no good having a tight fitting door with deep pile carpet at the bottom and/or no air brick and/or no open window etc..

and its no good turning the fan off immediately that you stop using the shower/bath..

as any moist air still in the room or in the duct is still there!!!

Where rooms have no opening window building regs suggest a 15minute run on timer.

Guinness