Damp shower room. No bathroom fan- just a ceiling vent linked to loft ducting with a pump midway along

[miramar]

I've just moved to this house.

There's a fully tiled shower room that has a condensation problem even after brief showers. There's what looks and sounds like an extractor fan flush into the ceiling. On investigating the loft, there's just a vent grille in the shower room ceiling, no fan. The vent grille is linked to the back of the house by 6ish metres of flexible ducting. Midway along the ducting is what looks like a fan or pump. So it seems that the air in the shower room is extracted (or not) by equipment several metres away from the room itself.

I expected to find a fan in the loft and either clean it or check the make and model to decide if it should be upgraded. Instead I've found something that I don't understand, and I can't find any info on the internet about this type of setup (possibly because I'm not searching for the correct terms.)

Any ideas?

The shower room isn't well heated (a separate heating issue) and has a window that is kept open in the night vent position. The fan is run for a long time before and after showering. There is a bit of a damp smell in the room. The shower room is at the front of the house and I expected the fan to be vented to the front of the house, but it's not. There's also a bathroom on the same floor which has an extractor fan that is ducted separately, also to the back of the house.

The pump/fan thing looks like this.

I'm no expert but surely the fan needs to be in the ceiling or wall (as close to the steam as possible) for it to be effective. Otherwise it's a bit like trying to hoover your hallway by wafting a nozzle around in the lounge.

As the hole is already there I would install a proper extractor in the room. We have just had one fitted in our bathroom (about 60quid I think) and it's made a huge difference to the condensation and dampness of the room.

I was thinking the same about swapping the vent grille for an extractor fan, but how to vent it? If I connect it to the existing ducting would I still need the weird black machine, and would both the new fan and the existing thing need to be active at the same time, I.e. the timers would match?

Unfortunately there's no obvious model or other info on the black thing, so I can't check online.

I think I need PigletJohn

Right I've just searched again, properly this time, no typos and it seems to be this-

www.vent-axia.com/range/linx-line.html

(discontinued

A range of 8 in-line mixed flow fans designed for use with flexible or rigid ducting. Mixed flow fans develop greater pressure than conventional axial fans making them ideal for use in ducted systems.

The LinX range consists of 4 sizes, 100, 125, 150 and 200 mm with air volumes from 190m³/h to 910m³/h in free air.

The compact size makes them ideal for use in restricted spaces such as ceiling voids traditionally found in refurbishment.)

Is that not a booster though rather than an extractor itself? May be used because of the long and bendy ducting needed to extract to the outside.

Hard to tell really. Can you do a bit of research re. Recommended fans for small shower rooms? A bathroom fitter/ electrician would probably tell you whhat you need for the space.

What you have got is a good inline ducted fan. It is better than a typical cheap builders fan.

It does not matter if the fan is at one end, or the other, or in the middle of the duct.

If you know anybody who smokes you could permit them to hold their disgusting fag under the grille and observe if it whisks the smoke away.

The flexible duct should have insulation flopped over it to prevent it getting cold and having the steam condense inside.

That type of fan is best wired so that it comes on with the light switch. Some people have an aversion to ventilation and will not turn fans on.

Thanks PigletJohn, from the manufacturer's info I found online I thought it should be more effective than a standard extractor. There's no insulation over the ducting, that should be an easy fix. I held flimsy toilet paper near the vent. When the paper was touching the vent, it was held in place, but could be pulled away easily. When held near the grille the paper wasn't obviously affected by air flow. I don't know any smokers but could try something similar.

The fan comes on with the light switch and runs for a while after the light is switched off. There's no isolator switch for the fan.

Some of them have two speed settings, but it is usually done by wiring to different terminals on the fan. Have a look for clogged grilles at either end from dust or cobwebs. Rigid ducts are smoother and better than the flexible hose, but more work to fit.

OOI, a bathroom fan is at is most effective with the window and door shut, then it creates suction. It will pull in warm air from the house under the bathroom door. If it is close to a window it might suck fresh air from the window out of the duct instead of clearing the room. Water vapour is lighter than air so if still, will rise towards the ceiling.

If the walls are uninsulated cold tiles they will be very prone to condensation. Do you have a hot water cylinder nearby?

P.s.

If you can see a way to run a duct to the front of the house, and it is shorter, the flow will be better, especially if done in smooth rigid duct.

The ceiling insulation looks poor and gappy. If buying more, look for loft rolls with Ecose treatement (it is brown not yellow) which does not shed dust and fibres. Knauf make it, but it is also own-labelled by Wickes and I think B&Q. It will say Ecose on the packaging.

Thanks again for the advice, I'll look into that. New, non-shedding insulation would be good. The hot water cylinder is downstairs from the shower room and at the back of the house.