Dehumidifiers 24 September 2022 at 11:42AM in Green & ethical MoneySaving 37 replies 4.3K views

ossian

Newspapers are full of pseudo-scientific articles promoting humidifiers as part of the current energy conscious world however their is little solid reasoning and I don't know if dehumidifiers are worth it for people without respiratory illnesses.   I get a bit of damp in my house, which is especially noticable if we go away for a few days.  In winter we dry clothes for a household of four in the utility room.  We get mould appearing in corners of the house.  I am keen to reduce tumble drier usage but we are at air drying capacity in the house and I don't want any more damp.  Will I reduce energy usage if I buy a dehumidifier or am I just adding to my electricity bill to get an air quality improvement?  I assume it would be a refrigerant one.   Thanks.

uk1

If you are looking for general air improvement rather than dehumidifying we have bought 8 x Levoit PUR-131 air purifiers and they are good value.  It has made a huge difference to our air quality.  We use kiln dried logs as a part of our heating and the Levoits keep the air sweet. They also remove a lot of cooking smells etc.  The house always smells sweet. 

QrizB

I can't speak for your specific situation but when we had a spare bedroom we'd dry laundry in it on airers, with a dehumidifier running in the room. This was slower but used less electricity than a tumble dryer would and we didn't get any signs of damp or mould in the room.

(We no longer have a spare room so we've mostly switched to machine drying when hanging laundry out isn't practicable.)

paul991

what  you need is a whole house mechanical ventilation heat recovery system. These remove the wet air  from the property replacing it with dry air with out removing the heat. Once installed running cost are low 

Northern_Wanderer

If you've got mould then you have a humidity problem and should take steps to improve that as you are damaging the building. If drying clothes inside, either open windows to ventilate (doesn't work well on a damp day) or use a dehumidifier. You can keep a check on humidity levels by using a Hygrometer. Acceptable levels of humidity vary by the season. Always ventilate to outside in rooms like kitchen or bathroom rather than letting moist air permeate the rest of the house. Humidity levels and mould growth are affected by temperatures as well. Best to get informed as you are doing.

Martyn1981

Hiya. We use a dehumidifier during the colder 'windows closed' months to finish drying off clothes. It works well, and allows us to use minimal tumble drying (on a low heat setting) before letting the clothes air dry with the dehumidifier. They also dry (hanging)  smooth, so no ironing needed.

But I would stress we have PV, so a lot of the time we are running this for free (so to speak). I think the dehumidifier is about 200W, but you get that back as internal heat gain.

But clothes aside, if you have damp and mould, then as others say, you need to do something, and a dehumidifier (if airing to outside isn't suitable) would help.

I may be wrong, but if there isn't a 'real' damp problem, such as issues with a wall, or damp proofing, then typically, damp/condensation in a house will be a result of our activities releasing more moisture inside such as showers, cooking, clothes airing, etc, than the house can air.

Magnitio

We use a dehumidifier in the colder months to reduce condensation. As humid air requires more energy to raise its temperature than dry air, there is an added energy saving benefit.

QrizB

There's a small benefit in that you also recover the heat of evaporation from the condensed water. IIRC for a typical 200W dehumidifier this can be around 60 watts, so a space heating COP of 1.3 or so.

silverwhistle

paul991 said:

what  you need is a whole house mechanical ventilation heat recovery system. These remove the wet air  from the property replacing it with dry air with out removing the heat. Once installed running cost are low 

You can buy single room units too: I'm considering one for my bathroom where it is obviously most benefical.

turnitround

I have one and it's the best thing I ever bought. I use it when the bathroom is all steamed up, I use it in son's bedroom as he hates sleeping with the windows open so in the winter months the windows are wet.
I dry my washing with it during the winter months, I put clothes on hangers on the landing or in the spare room and it's amazing how quickly they are dry.
It's not expensive to run at a fraction of what a tumble dryer would cost. Wouldn't be without it.

paul991

Has any one came across a single room through the ceiling mvhr unit