Damp room/dehumidifier, etcetera.

Hheyes

The lounge in my son's (modern-ish, small mid-terrace) house smells musty, although there's no visible condensation or mould. And, when it's rainy (even is summer), the wood-tile floor buckles in one particular area (perhaps oddly, on the 'innermost' side rather than near the exterior wall with the sliding door).

Like me, he rarely feels cold and prefers a cool house. Although the room can feel a bit clammy early morning, it soon warms with daylight and doesn't feel particularly damp (I've lived in old houses where the skirting was rotting due to high damp).

I think that the musty smell is probably from the upholstery, due to the room having been too cold during the 5 years he's been there. So when I suggested that he increase the temperature during winter to help alleviate the issue, he told me that he's done that previously - to no great effect.

Trying to help, I've considered dehumidifiers. As a potentially ongoing 'slight damp' issue, rather than recovery after a flood or similar incident, I don't think short-term hire of an industrial model would be appropriate.

Whilst trying to understand enough to be able to know what I'm buying, as a temporary measure I bought a low-power portable Peltier-type unit. There seem to be several brands/models with similar-power outputs, although the 'suitable for room size' figures vary hugely. User-reviews vary from 'wonderful' to 'useless' and so do little to aid clarity.

Although it's too small to do much for the whole room, I'm hoping that if placed by the problem floor area it'll hopefully be some, albeit limited, use in shrinking the floor enough to lay flatter.

It's only been there a day, but I'm now wondering if it might be totally ineffective... without confusing myself too much with figures, the stated extraction rate of up to 250ml daily is probably less than the water content of the exhaled breath of one person.

So, I expect it'll quickly be repositioned in an under-stair cupboard which sometimes has damp shoes and coats, and I'll probably need to spend £150-or-more to get something suitable.

I also bought an inexpensive thermometer/relative humidity meter, which is indicating 83% at 16 degrees. This seems inaccurately high RH... but I don't understand enough to be sure.

With neither the desire nor budget to spend more than is necessary, I'm posting here in hope of appropriate advice from others who've more experience.

Perhaps relevantly, I'm wondering if the issue is one of damp rising from the slab - although common sense suggests that's unlikely as the problem is worse when raining. Having removed a square-foot-or-so of tile so we can at least open and close the door, the tiles appear to have been laid directly on the sealer-coated slab.

stator

Well you're right that the cheap small dehumidifiers don't really do much, you do need to spend at least £100 for a decent sized one.
83% seems very high but it would only collect on cold surfaces, in an old victorian house that would be the outside walls and/or windows. But if you have a modern properly insulated house the walls might not get cold. Are the windows cold?

Hheyes

stator wrote: »

83% seems very high but it would only collect on cold surfaces. Are the windows cold?

Thanks.

The walls are batten/plasterboard, and so aren't cold. The window in that room is a patio door, with what looks like a decent air-gap and so doesn't feel particularly cold... and I've never seen condensation on it.

The RH is currently showing 87% at 15 degrees - and that temp is probably the lower limit of the stated operating range for the dehumidifier (which seems to have removed about 50ml in 18-20 hours).

I'd have thought that at that level of RH things would feel very uncomfortable - but much of this is beyond my understanding.

benjus

How much is the dehumidifier actually extracting?

There is no noticeable dampness in our flat, but when I run the dehumidifier (desiccant type, EcoAir DD122 MK5 Classic) for a few hours it collects a pint or so of water (I bought it for drying laundry indoors).

I think only desiccant dehumidifiers are likely to work well at 15 degrees.

Hheyes

benjus wrote: »

How much is the dehumidifier actually extracting?

Thanks.

About 50ml in the first 18-20 hours.

benjus wrote: »

There is no noticeable dampness in our flat, but when I run the dehumidifier (desiccant type, EcoAir DD122 MK5 Classic) for a few hours it collects a pint or so of water (I bought it for drying laundry indoors).

That's interesting. My son also dries washing - but in his bedroom... which, like the rest of the house, seems fine.

benjus wrote: »

I think only desiccant dehumidifiers are likely to work well at 15 degrees.

Could be a problem. That temp feels fine to us, and we both like to open windows and get fresh air. I've lived in some not very good houses over the years, and never had an issue like this.

I notice that the floor doesn't have a full-perimeter cork expansion strip - and this clearly won't help.