Siting a bathroom extractor

[Jupiter01]

I have an en-suite which is approximately 3.5m long and 1.2m wise. There is a shower enclosure at one end and the toilet at the other end.

It would be easier to site a extractor on the wall where the toilet is mounted but conscious that it’s away from the shower. Is that okay?

 

[Rad1o]

Our en-suite is like this and I put a humidistat extractor fan above the shower as that is where the steam is and the other side we have a good size tilt and turn window for ventilation. Depending on your ceeling joists direction you might be able to easily push a hose through.

 

[dilalio]

Should be opposite end of doorway or window so that a through draft is set up... Fresh air in through door and extracted through vent... Sometimes you are just governed... Also above a wc is good as it will help get rid of odours

 

[Jupiter01]

Thanks guys. As luck has it, the joists are running in my favour. I could site the extractor in the middle of this room and then have a duct which pushes it through the wall, further along.

Q. Am I okay to have a duct which is 1.5 metres in length and which type of duct should I use please e.g. flexible, rigid, foil, etc.

Thanks for your help.

 

[dilalio]

So, sounds like you're considering a ceiling mounted vent. Rigid is best and ideally you'll want a fall on it, away from the fan so that any condensation will drain away from it to the outside... Using flexible duct means water will collect in the ribs and go stagnant.

 

[Jupiter01]

Yes, ceiling mounted after the suggestion of floor joists in an earlier response. Appreciate the tip on the fall. Presumably, I need to go slightly higher first (vertically) to achieve the fall you have mentioned?
Final question for now please, are these rigid duct pipes always the same size? I am trying to determine which diamond core bit I will need for this.

 

[JohnD]

they vary a little. I made the mistake of using soil pipe which is readily available and cheap, but the internal diameter is too tight for many modern fans. Ducts are nominally around 100mm usually and around 114-118 externally. If you are mortaring them in a little extra space is OK.

If you go to a ventilation duct merchant (e.g. on ebay) you will find a wide range of ducts, elbows, backdraught shutters, cowls and connectors at a good price, and if the same brand they will all fit.

if the duct passes through an unheated space you can buy an insulated version which reduces condensation. Otherwise wrap well in loft roll.

If you can conceal an inline fan it can be quieter and three times as powerful as an ordinary bathroom extractor. A timed overrun is useful for a shower room as they take a long time to dry. With a quiet fan this will not be annoying.

 

[dilalio]

You can get rectangular ducting with adaptors to go from that to circular, which may help with a fall. Look at Manrose products

http://www.manrose.co.uk/accessories.htm

 

[Jupiter01]

Unless I have misunderstood, even if I concert to rectangle from circle, there is a need for the vertical pipe from the extractor to go up before the horizontal section can slope down?

 

[dilalio]

Yes

 

[Jupiter01]

UPDATE: All in place and operational now. I used rigid pipe and got the sloping pipe (as per suggestion) in place too. There's one issue (two actually) that are worth sharing as it caught me out in my first project with rigid duct piping and may help others.
With the vertical duct pipe popping out of the ceiling, I didn't pay much attention to the level and ensuring it is dead straight before I fitted the new ceiling. This meant that when I went to push the extractor onto this pipe and screw it to the ceiling, the bathroom extractor isn't flush!
Similarly, because the pipe exiting the exterior wall is at a slight slope, the vented grill is also not flush on the wall.

Perhaps the flexible ducting is more suited to this type of project in hindsight?

 

[foxhole]

UPDATE: All in place and operational now. I used rigid pipe and got the sloping pipe (as per suggestion) in place too. There's one issue (two actually) that are worth sharing as it caught me out in my first project with rigid duct piping and may help others.
With the vertical duct pipe popping out of the ceiling, I didn't pay much attention to the level and ensuring it is dead straight before I fitted the new ceiling. This meant that when I went to push the extractor onto this pipe and screw it to the ceiling, the bathroom extractor isn't flush!
Similarly, because the pipe exiting the exterior wall is at a slight slope, the vented grill is also not flush on the wall.

Perhaps the flexible ducting is more suited to this type of project in hindsight?

Just cut flush, the pipe should not exit wall or ceiling.

 

[Jupiter01]

I have had to leave some of the pipe poking out of the ceiling as I need to push into this duct, the extractor. Once the extractor was pushed into the duct sticking out of the ceiling, I pushed it and screwed the extractor to the ceiling. However, I wasn't aware of the criticality of ensuing this pipe is dead vertical.

Does this make sense and/or am I missing something?

 

[Jupiter01]

I was wondering if anyone can comment on the above? Have I misunderstood something and have I drawn the right lessons.

 

[Nige F]

If the extractor lies flat to the ceiling (sounds like it does) you're fine