Black Mould

MouldyOldDough

What about heat exchanger fans?
(those that extract damp air but not heat) 
Screwfix doesn't list any 

Phil4432

MouldyOldDough said:

Emmia said:

MouldyOldDough said:

Our dehumidifier meter reckons that our house humiity averages 65% - does that sound acceptible ?

65% sounds a little high, ours is about 50% these days - when it was 65% we had a bit of a mould problem.

OK How do we reduce it to more reasonable levels ?

If we leave the dehumidifier on for 24 hours - and get the humidity down - won't the moisture re-enter the house when the fronr door is opened ?

Depends on the day; if the humidity outside is low it could have the opposite effect. 

One person on the forum said that they will not vent despite their mold issues, as they feel they'd be losing heat.  Its a point, but if the ambient temp of your house is 18C and above, you wont lose that much heat with an hours venting.

You have to vent your house, its worth losing a couple degrees heat to do so.  Bit of an aside, but thought I'd mention.

Venting when cooking, bathing is very important.  Doors for those rooms should be closed when cooking/bathing.

Phil4432

MouldyOldDough said:

the_lunatic_is_in_my_head said:

Bleach tends to remove mould on the surface but not get to the roots inside the materials it is growing on, mould cleaners should have additional ingredients that kill it off properly. 

We had a go this morning with CILLIT BANG mould cleaner -  this has got rid of all of the mould on the actual ceiling - but not in the corner - we used a sponge and old paint brush to apply.

It does say on the bottle "works best on non-porous surfaces" - but it has worked a treat on the ceiling !

Sure its not the stain left by the mold?  If so, that wont come off with mold cleaner, you'd need a stain block paint then paint over the top. 

MouldyOldDough

I have found them - they run at 2 watts on low power

2 watts – 1/500th of a unit per hour

1 Unit = 20p

So 20/500 penny per hour

Or 2/50th penny per hour

Or 1p per day

is this correct ?

Emmia

MouldyOldDough said:

What about heat exchanger fans?
(those that extract damp air but not heat) 
Screwfix doesn't list any 

If you're keeping your house at 14 degrees, then I'm not sure there is much heat to exchange (you will lose warmth from the air coming back in) - a google search indicates they're £250 + so, roughly 2 - 3x the cost of a fan with a humidstat and no heat exchanger.

MouldyOldDough

I have always assumed that to clear damp - you need fresh air (hence have opened windows) - but, thinking about it - if the house is, say 60% humidity and outside is 80% - is it not best to keep the windows closed because outside is more humid than inside ?

Or is there more to it than that ?

I know that warm air holds moisture in suspension better than cold air

grumbler

MouldyOldDough said:

I have always assumed that to clear damp - you need fresh air (hence have opened windows) - but, thinking about it - if the house is, say 60% humidity and outside is 80% - is it not best to keep the windows closed because outside is more humid than inside ?

Or is there more to it than that ?

I know that warm air holds moisture in suspension better than cold air

80% at 5C becomes about 40% if heated to 20C (50% at 15C)