Mould/condensation and dehumidifier help

Fire_Fox

Fleabag wrote: »

There's no extraction in the bathroom, only the kitchen ... We don't have a tumble dryer, and do sometimes dry clothes indoors when it's too wet to hang them out (hopefully the dehumidifier will easily deal with that).
I suppose I have reservations that one unit, even more powerful than recommended for a house of our size, will be able to draw moisture from a room so far removed from it.

Does not sound like the window structure is the problem, but rather the lack of a ventilation strategy. Purge ventilation becomes much more important in properties without background or mechanical ventilation. Briefly throwing open the windows at either end of the house, or in the areas worst affected by condensation that day can make a big difference. Although you will lose the warm (damp!) air, the building itself should act as a reservoir of heat so it is not chilly for long.

Like you, I am not convinced a single dehumidifier can substitute for a bathroom fan, kitchen cooker hood, tumble dryer as well as deal with general humidity (breathing, making hot drinks, mopping floors, washing the dishes).
Having two portable dehumidifier units would be more flexible. Then you could target tools and laundry, or kitchen and bathroom.

Fleabag

Yes, I have thought that a second unit might be necessary to deal with the studio, especially given how important it is to keep my tools dry - though I wish that wasn't the case.
I think I may start by running it downstairs centrally or towards the back of the house for a few days before siting it upstairs, in the hope this might improve the whole house humidity. Another option is to run it on the landing, but bring it downstairs for a couple of days a fortnight, as my step sons would be here and likely to trip over it in the dark if it stayed on the landing then. I'd have to get my other half to move it around, as I have arthritis, so can't lug it around the house

Fire_Fox

Good luck with the experiments: let us know how you get on!

spirit

I'm surprised that no one has mentioned the cavity wall insulation as a possible cause in a house of that age. A quick search on this board will unearth plenty of info/evidence.

Doozergirl

The root cause of condensation isn't our lifestyles, it's a fundamental issue with how the house is working, usually because of the 20th century obsession with blocking everything up. Most of us can live perfectly well without any condensation, despite 'modern lifestyles'. Doing inconvenient things like washing and breathing isn't the problem, although it's clearly producing moisture.

I agree that ventilation should be managed properly, air bricks in the subfloor are essential and cheap - what are you waiting for?, extraction in kitchens and bathrooms is essential, humidity sensing fans would be a good idea. Trickle vents can be fitted to windows retrospectively. Are the windows fitted correctly? I know we're talking about ventilation, but if you've got constant cold blowing in from around the edges from failed sealant, unit seals or just huge amounts of air where windows have been placed in openings much larger that the windows then you're going to have a permanent draft.

Have fireplaces been blocked up in the house? Open them.

Not many houses from 1893 have cavities. If they do, they're very small and the amount of insulation you can fit is only small and probably not very effective - even if it were fitted correctly. Insulation can be really helpful in removing the risk as the internal face of the wall stays warmer.

Your gas heater in the studio will be producing lots and lots of moisture - you're heating the air to increase the amount of moisture it can hold, but if you close the door at night then the temperature will plummet and the water in the air needs somewhere to go!

You need to address your heating as a matter of importance. If the house is cold while you're living in it, then condensation is going to be virtually inevitable.

You should also check for general damp in the house caused by problems with rainwater goods, breaching of the damp proof course etc as moisture inside walls will also reduce the temperature of the walls.

Erica_L

Why would not you just place 2-3 smaller dehumidifiers on different floors? I guess it would be more effective than one but big.

neilmcl

Erica_L wrote: »

Why would not you just place 2-3 smaller dehumidifiers on different floors? I guess it would be more effective than one but big.

The thread is a year old.

dunroving

neilmcl wrote: »

The thread is a year old.

I spotted that also, but I often wish we would get an update on some threads like this one - I wonder whether the OP solved her problem, or what she learned in trying to solve it for example.