Bathroom extractor fan recommendation

deeobrien

Hi All,

I renovated my ensuite about 2 years ago. Before the renovation, I had no problems with dampness. The room is in a dormer house so the room has a sloping roof. The ensuite had an extractor fan that came on automatically with the light. There was no window in the room. A Velux window was installed as part of the renovation. The plumber replaced the extractor fan. It turns out the previous fan was an inline fan in the attic. He removed that and taped up the duct where it had been. The ducting has a 3 to 4m run across the attic to the roof vent tile. I don't know why the roof vent is so far from the ensuite - perhaps the house layout changed in the past.

Since the renovation, I've had big dampness problems in the ensuite. On damp/humid days the water is literally dripping from the ceiling even with the fan on and window open. I think the fan is not powerful enough or perhaps given the length of the ducting run, or it should have an inline fan? Or maybe a new roof vent tile?

There are a lot of extractor fans out there - is there any particular brand I should look at? Also if I were to get someone to sort out this problem for me what kind of trade would it be? A plumper? electrician? or some other trade?

Thanks,

Deirdre

10-10-20

Hi, is the new fan still on an over-run timer and how long is that set for? Can you feel it pulling the air in if you put your hand to it? And finally, is there sufficient clearance under the door to allow the air to circulate in and replace the air that the fan is pulling out of the ensuite?

deeobrien

There is no over-run timer on the fan - it goes off with the light. I normally leave the light on for a while afterwards (10 mins or so). There is a gap under the door and I typically leave the door open a jar anyway. The Velux window in the room is open a bit as well. It's a small space.

It's an Xpelair fan with a round front (looks like this one Xpelair C4SR 100mm (4") Axial Bathroom Extractor Fan White 220-240V - Screwfix). I put my hand up to it (had to put my hand right into gap under the cover) and I could feel air (although it didn't seem very strong to me).

10-10-20

Inline fans tend to be more powerful than the wall-mounted units, so that's one of the significant issues there as that long duct is causing the pressure to drop and the fan to become less effective.

If you're sticking with a wall-mounted fan then you definitely need a timer or humidity controlled unit as you'll need around 40 mins to an hour of run-on time to clear a small room of high humidity. Even at that it could probably benefit from being run for 20 mins every hour after that as things like towels dry off. You might be best off looking at a humidistat based fan as that would automate some of this for you.

https://www.chadwicks.ie/breeze-timer-humidistat-fan-white-74468.html

There are no inline fans with humidistats that I know of unfortunately.

But how the room isn't improving even with the Velux slightly open is unusual - it suggests that there isn't through-air-flow.

Anyway - back to the question of who takes care of these issues… it's no-man's land in that respect. The best advice would be to engage an electrician for it as the job needs to be compliant to the electrical spec as it's a bathroom, but a plumber or even a roofer might be more capable of completing the job to a higher spec… 😕

deeobrien

Yah, it's strange, I'd have thought an open window would help. On dry days I don't have that much of an issue, but on damp or humid days it's more of a problem. The shower stall is walled on 3 sides (opposite end to the Window) so it's a very enclosed space in an already small room which probably doesn't help. The paint around the fan on the ceiling is starting to crack again - despite being painted with a BIN anti-peal paint and bathroom-specific ceiling paint.

I have another larger bathroom (Also with a sloping roof on one side) with no fan but a more open shower space and it doesn't have the same issue.

Thanks for the advice.