Upgraded bathroom extractor, still misting up problems

[garmcqui]

Hi all,

Newbuild (in 2014) house, main bathroom has no windows and mists up terribly when anyone has a shower, especially the large mirror.

Here's the layout:

The original fan was a horrible looking surface mounted Nuaire Genie, which according to their specs produced a rather weedy max flow of 25L/s:

So I've upgraded the fan to an inline Manrose MF100T, which produces noticeably more airflow (max flow of 68L/s). But the bathroom still mists up badly, even if the door is left open a crack.
Any suggestions? Would moving the fan grille to above the bath/shower help? What about using a 100mm Y-junction (which I have) and having the existing grille AND a 2nd above the bath/shower?

(still some patching up to do to ceiling!)

Any suggestions appreciated!

Thanks,

Gareth

 

[JohnD]

the picture of the loft ducting won't enlarge. Can you show us where it comes out?

you say there is good airflow. When does the fan turn on and off?

 

[garmcqui]

Thanks for replying.

Yes, airflow seems to be good enough, will easily hold a sheet of A4 paper up against the grille.

Hopefully these photos will work.

Fan comes on with the bathroom light (which, as there is no window, is any time someone is in the bathroom) and, unlike the previous fan, stays on for ~10mins after light is turned off.

 

[big-all]

do you have about a 12mm gap under the door to draw warm air from the rest off the house to allow airflow

 

[garmcqui]

Not at present, but I will have soon (once I get my hands on a plane).

But today I had the bathroom door ajar, so there was plenty of air able to be drawn from the rest of the house.

Starting to think that a mirror that size in a smallish bathroom will always steam up when someone's in the shower, regardless of what I do. Just wish I could add heating pads to the back of it, but it's bonded to the wall (why, I don't know!).

 

[foxhole]

The manrose is woefully under power required, My son in law bought it for the same reason and has the same problem still.
Needs something like this.
https://www.tlc-direct.co.uk/Produc...MIrfK3tfWx1QIVhjLTCh3jsgqUEAQYBiABEgKH_fD_BwE

 

[cwhaley]

I would agree with Foxhole. When I bought my house last year it had a tiny little Manrose thing and we had terrible problems with wet walls and a mirror that steamed up. I bought a new in-line fan which extracts at 157 L/s. It seems like overkill but it reduced the steam clouds and things are nowhere near as bad.

We still get condensation issues on the upper external walls but that's because we're in a house with solid brick walls; the bathroom is a room I have not insulated yet so there's only so much you can do. One day I intend to get it tanked/waterproofed so any condensation simply runs down the walls and into a drain leaving the external brick dry.

I have always thought bathrooms in Britain are woefully inadequate compared to ones I've seen in European property guides and magazines. So many of ours' are just like ordinary rooms that somehow deal with huge volumes of water and water vapour.

This is the fan I bought http://www.extractorfanworld.co.uk/turbo-tube-pro-150-6-inch-inline-fan-with-timer-3793-p.asp

 

[foxhole]

I used a 6" fan connected to twin 4" hose inlets via a Y joint.No condensation at all even to ceiling height mirror adjacent the shower

 

[cwhaley]

Although a fan isn't the one-stop solution for all - there's too many variables (north facing wall, distance of fan, size of bathroom, volume of water vapour, etc., etc.)