Low energy dehumidifier?

rightee · Post by **rightee** » 17 Jul 2010, 10:05

Hi all,

Our rented flat is in a 200 year old house with really thick walls and over the winter we had a lot of problems with humidity and damp on the walls of the bedroom. This room doesn't get any sunlight during the winter (and also in the last few days it's been getting damp again due to the sun)

It seems to me like the only solution is some sort of dehumidifier? But I know they can use a lot of energy, we'd only want to use it intermittently - probably during the day to get the majority of the moisture out of the room.

Anyone got any potentially low energy (and low cost) solutions?

JohnB · Post by **JohnB** » 17 Jul 2010, 11:11

I've got a dehumidifier bought from the local electrical shop. There wasn't much choice, so I just got what was available. I haven't checked the actual electricity usage, but it generates some heat and helps to heat the room, so you can turn the heating down a bit.

Post by **adam2** » 17 Jul 2010, 14:15

Dehumidifiers dont vary that much in energy used per L of water extracted, I would buy any well known brand that you like the look off.

All the ernergy used by a dehumidifier ends up as heat, so is only wasted in mild weather when a dehumidifier is unlikely to be needed.

If you have an off peak electricity supply then it is worth using a timeswitch to only energise the dehumdifier during off peak hours, this will be much cheaper and greener.
At my mothers home, 3 dehumidifiers cost in total about 15/20 pence a day to run (total loading for all three is about 600/700 watts, used from 02-15 until 07-45 every night)
They are used about 100 days a year.

If you dont have an off peak tarrif, it could be worth changing to one, depending how much energy use you could shift to nightime hours.

In mild sunny weather damp can somtimes be removed by simple ventilation, but in cold wet weather a dehumidifier is very useful.

rightee · Post by **rightee** » 17 Jul 2010, 14:26

Cheers John and Adam.

In warm weather we've had the window open which solves any problems, but it sounds like in the winter the dehumidifier could work well as we have a wood burner in the main lounge room and rarely have the heating on. So the dehumidifier could warm the bedroom area up slightly.

http://www.DODGY TAX AVOIDERS.co.uk/Delonghi-148110 ... 38&sr=1-13

This one seems to get quite good reviews so we'll look into it for the winter.

Cheers,
Andy

JohnB · Post by **JohnB** » 17 Jul 2010, 17:41

I was advised to only buy one with a humidistat. This is the one I've got, and was about £160.

This is quite a useful discussion to read on dealing with damp. It's a bit disjointed, but I picked out the bits that were relevent to me.

emordnilap · Post by **emordnilap** » 17 Jul 2010, 18:25

rightee wrote:Cheers John and Adam.

In warm weather we've had the window open which solves any problems, but it sounds like in the winter the dehumidifier could work well as we have a wood burner in the main lounge room and rarely have the heating on. So the dehumidifier could warm the bedroom area up slightly.

http://www.DODGY TAX AVOIDERS.co.uk/Delonghi-148110 ... 38&sr=1-13

This one seems to get quite good reviews so we'll look into it for the winter.

Cheers,
Andy

It's a very reliable, solidly built model. We have one for winter, to use in the shower room after a shower otherwise it soon mouldies up. In summer, it's only necessary to use it if the weather is cool and damp.

They're also useful to have anyway (they'll last for years) after any building work, to help move the job along where plaster and cement have been used.

Usual reservations about electrical appliances and water apply.

The water can be used in a iron, though there does tend to be a lot. You can take the water container out and dump the water in a water butt.

Generally I try to minimise use of any electrical items (I only realised the other day that I only ever use one electrical item in the kitchen) but our supplier provides 88% wind generated, so it eases the conscience a tiny bit.

rightee · Post by **rightee** » 17 Jul 2010, 19:46

Thanks, yes we also try to not use anything electrical if not necessary.

Our (myself and wifes) weekly meter reading has average 20kWH for the first 8 months we've lived here. So I'm imagining one of these devices might bump that up a lot.

RenewableCandy · Post by **RenewableCandy** » 19 Jul 2010, 21:17

If it's only one room where most of the damp is produced (e.g. bathroom) you could try installing a single HRV fan. About £300 bought-and-installed but uses only a few watts most of the time, going up to about 50 when it detects damp air that needs shifting. Air quality's nicer too, because it brings in air from outside (warms it using the heat from the expelled air).

madibe · Post by **madibe** » 19 Jul 2010, 22:39

?

erm...we are talking TEOTWAWKI and de-humidifiers?

erm... we are talking oil crash..

erm population runaway..

erm... feckwinkle

RenewableCandy · Post by **RenewableCandy** » 19 Jul 2010, 22:55

Look, if I'm sitting down to a tasty potage of my neighbour's squirrels, I don't want the experience to be ruined by peeling wallpaper and mildew, do I? One must have standards.

JohnB · Post by **JohnB** » 19 Jul 2010, 23:13

Do you fancy popping round and removing 2" of very hard cement from my internal walls, cement render from the external ones, and the concrete path that's on floor level and touching the outside of the walls, Maudibe? It shouldn't take you many weeks! After that it all needs re-pointing with lime mortar. Then after 6 months or so the walls should be dry, and the damp gone. If not, I sometimes need to use a dehumidifier to make the rooms usable, until the work can be done. Unfortunately it's one of those things that has to be used during the transition from where we are now, to where we need to be.

emordnilap · Post by **emordnilap** » 20 Jul 2010, 11:59

I'd rather have a dehumidifier than a dishwasher.

JohnB · Post by **JohnB** » 20 Jul 2010, 12:19

emordnilap wrote:I'd rather have a dehumidifier than a dishwasher.

I know I've said it before, but I have to run my bloody dishwasher occasionally to stop it smelling. I've no idea how to use it for washing dishes!

rightee · Post by **rightee** » 20 Jul 2010, 12:37

I know the end of the world is nigh, but while I can, I'd like to avoid black mould on my bedroom walls! (just until the power goes out of course, then I'll just have to get on with it!)

OrraLoon · Post by **OrraLoon** » 20 Jul 2010, 18:35

RenewableCandy wrote:If it's only one room where most of the damp is produced (e.g. bathroom) you could try installing a single HRV fan. About £300 bought-and-installed but uses only a few watts most of the time, going up to about 50 when it detects damp air that needs shifting. Air quality's nicer too, because it brings in air from outside (warms it using the heat from the expelled air).

Bought something called the Prem-I-Air for £79 aboot 3 years ago. Somewhat surprisingly it did arrive one sunny day from afar. Does the job.

But then it's for my bedroom. Where it only occasionally gets hot and steamy.