Extractor Fan

[casper46]

Hi i wonder if anyone can give me me any advice

I am going to fit a shower in a downstairs utility room in a flat roof extention .
The shower will be in a corner next to an interior wall and am looking to fit a fan vent in the ceiling above and vent it out through the garage and out through the wall using approx 4 mtrs of ducting . I would as there is very little room aboce shower have the actual fan on the inside of the garage wall . Is a fan powerful enough to suck the air 4 mtrs and push it ot .

Thanks

 

[Taylortwocities]

It depends on the fan!

Cheapo 10mm fans can barely push air through a 9"wall.


A centrifugal fan usually has a better performance for longer duct runs.
Something like this
http://www.xpelair.co.uk/premier-dx180-dx200-and-cf20-centrifugal-extractor-fans.html

 

[ericmark]

The main problem in extracting moisture is that it will condense in the pipe. The pipe needs a slope if only slight to ensure water can run out. In the main this means smooth sides so even a small fan will push out some air but as to if it will push out the air required by building regulations is some thing else.

What controls the amount of air extracted more than fan size is the size of ducts to bring air into the room. Clearly if air is dragged under doors only no fan will push out much air. Vents in the door is a common way to allow air into the room.

Of course careful consideration must be given to any open flue appliances this means anything which burns fuel which does not have a balanced flue including any gas cooker. Where open flue devices are used better option is to use a heat recovery system which pumps air in as well as out so does not produce a negative pressure in the house.

Reading the building regulations it is rather contradictory at some points it says same room and in others treats the home as a whole. One has to look at the vents into the home and decide where any extracted air will come from. I know with solid fuel fires putting vents right by the fire can really reduce drafts so you may need to consider an input of air as well.

 

[casper46]

Thanks to both of you for your replies but I am unable to put fan near shower so what i want to do is put it at the end of the 4 mtr run and would an inline fan be better

Thanks

 

[Taylortwocities]

Where would you put the in-line fan. I thought you had a flat roof?

 

[casper46]

Sorry I didnt explain myself well enough it is a flat roof but it has quite a slope so where the shower will be is in the corner under the loowest part which does not reallt allowe enought depth above to fut a fan but the extention is joined to the garage so what i would like to do is have the vent at side of shower and have duction run through wall into garage and run along and went out of the garage wall via a fan either just in garage so would pull aiar from shower and push it alonf duct sme 4 mtrs out of garage wall via vent

Thanks

 

[Taylortwocities]

OK

One of these will sort you out then....

http://www.tlc-direct.co.uk/Products/SLTDK250T.html

 

[1028741]

As others have said, choose a high-performance centrifugal fan. Installing it as far away from the shower as possible will make it very quiet. The MOST IMPORTANT consideration is to use INSULATED ducting, I learnt this the hard way. In the garage, water will condense in an uninsulated duct, causing mold and dripping. Either use this flexible duct:
http://www.tlc-direct.co.uk/Main_Index/Ventilation_Index/Accoustic_Ducting/index.html

or as it is running through an unheated garage, rigid PVC or galvanised duct would be best, but must also be wrapped in foil-faced insulation and taped:
£8 for 3 metres http://www.ductstore.co.uk/acatalog/galvanised_spiral_tube_lengths.html

or http://www.fastlec.co.uk/ventilation-ducting-thermal-duct-insulation-c-329_2151.html

 

[casper46]

Thank you all for your replies and now know what to do