Do in-line extractor fans require maintenance?

[Johnny2R]

Putting a thin layer of loft insulation over the vent pipe should sort the condensation

I did that earlier, over the duct as far as the inline fan (the rising section). I'll find some more to put over the section on the other side of the fan but I'm thinking that any condensation there would probably just run out through the soffit vent.

 

[Harry Bloomfield]

I did that earlier, over the duct as far as the inline fan (the rising section).

That insulation, was likely why you found no moisture in the duct, when you cleaned it out.

 

[Johnny2R]

No, I did it after I'd completed all the cleaning.

 

[Lower]

Everywhere

Nearly no properties in this country are built with anything like a decent level of air tightness. There will likely be square metres worth of gaps, cracks, holes and splits throughout the structure, around windows, doors, floor edges and between floorboards, in the loft, around service entry points.. You name it; point a camera in any direction and I bet it'll catch at least 3 potential sources

So you're saying don't open a window because you'll pull in moist cold air, but you're happy to pull in moist, cold air through other leak points in the house?

Don't forget that the moist, cold air will rapidly heat once its in the house, and as it heats its relative humidity will drop rapidly and therefore will no longer be 'moist'. Whereas the bathroom will be full of warm, high relative humidity, saturated air that you're much better getting rid of and replacing with air from outside that will be much drier once warmed up.

 

[yorksbuilder]

Humidity outdoors in UK oct-mar can be very high, so its likely to be damp air coming in when your window is open.
Usually there is a standard gap you need under a bathroom door to allow air flow.
Saying that, I always have ensuite doors closed when showering as want as little moisure to get into the bedroom as possible, and have the window open a bit, and rely on that and the door gap. Plus 20 mins overrun timer, better to have it running on a bit and remove the moisture. Do shut the window sometimes when its very cold or windy

 

[Harry Bloomfield]

Humidity outdoors in UK oct-mar can be very high,

True, though quite low at the moment, due to the cold - 61%, I make it. Indoors is not much lower, at 55%.

so its likely to be damp air coming in when your window is open.

True, and the airflow/wind, needs to be blowing in the correct direction, window on the lee side, for it to draw moisture laden air out.

Usually there is a standard gap you need under a bathroom door to allow air flow.

The air volume able to enter the room, needs to perfectly match the air being extracted, for it to have the best effect in removing the moisture laden air. Have the bathroom door open too wide, and the moisture is able to spread beyond the bathroom. Cross-flow, through an entire room, is also worthwhile - so an extract fan is drawing air out from one side, with replacement air coming in from the opposite side of the room.

 

[Bayardmm]

I fitted a Manrose 100mm Standard Mixed Flow Fan in the attic 3 years ago, to replace a failing fan there. Of late we've been getting an unusually high level of condensation in the bathroom after showering, and I've been trying to determine the cause. There was a fair bit of gunk build-up on the grill above the shower, and also on the grill in the soffit outside, and I've cleaned them both and hoovered out the insides of the duct as much as possible. But I was wondering if the fan itself might be pulling less air through, and might need some kind of maintenance. Or is it a case with these fans that they tend to either work fine or fail completely?

I used a vacuum cleaner nozzle on our inlet side and dislodged the trunking. I went into the loft to refit it and was amazed at how much dirt had accumulated on the fan blades. Used a small brush to clean it and its efficiency improved considerably. You could see steam being drawn into the inlet.

 

[robinbanks]

So you're saying don't open a window

Don't remember saying that, sorry

Are you confusing my post with someone else's?

you're happy to pull in moist, cold air through other leak points in the house?

Naw, if you look for other ventilation related threads that I participate in you'll find me banging on about MVHR; I'm a big fan of recovering as much of my paid-for heat as possible into the incoming fresh air, when dumping stale air out the house

Controlled ventilation is one of the most significant upgrades houses in this country sorely lack, despite improvements in other areas of building regulation

 

[foxhole]

We always put the heating on for 30mins before a shower , warm room supports moisture allowing time for extraction to work .
Cold room ( window open) rapidly condenses moisture to walls .

 

[Lower]

Don't remember saying that, sorry

Are you confusing my post with someone else's?


Naw, if you look for other ventilation related threads that I participate in you'll find me banging on about MVHR; I'm a big fan of recovering as much of my paid-for heat as possible into the incoming fresh air, when dumping stale air out the house

Controlled ventilation is one of the most significant upgrades houses in this country sorely lack, despite improvements in other areas of building regulation

Yes, i am confusing your post with someone else's. Sorry

I agree on controlled ventilation.