Cheapest = open your window wide during a shower and for a while afterwards, but tried this last night, not sure I'll do it again, -2 degrees not the best temp to step out of a warm shower. Perfect in the summer.

Next cheapest = extractor fan, simple and effective, plus without the severe freeze you get with an open window.

Then you get to dehumidifiers, that are really most effective at dealing with the aftermath of leaving the window shut/extractor off and the rest of the house is now damp. They are expensive to run, but usually quite effective. I tend to use a dehumidifier to remove any lingering moisture after a shower.

There are two types of dehumidifier, those that work with a compressor, these use a similar process to the freezer, but in reverse, so you chill the air, condense the water and extract. What they don't tell you is that the 4l per day or whatever rating is based on living in the tropics, with high temperatures and humidity, 4l becomes 2l at 20 degrees, i.e. a relatively high temperature, 1l at 15 degrees and barely anything at lower temps - the exact amount depends on the brand and generally cannot be gleaned from the literature, because they don't want you knowing this. Plenty of people will tell you their compressor dehumidifier works as intended, but as this is down to laws of Physics and not the manufacturer using clever technology, it's largely wishful thinking.

The other type is the desiccant dehumidifier, this works by using a similar material to silica gel, which absorbs moisture, this is then heated to expel the water which is collected. These do not vary so much depending on temperature, but the rub is, you're heating stuff, which costs electricity, on average it can cost twice as much to run, but you do warm the room up. These are also supposedly more likely to break down, even though they are simpler in design - I can't comment as mine works fine.

I have one of each type, cold rooms and damp (it's Manchester = wet). Both machines are rated to the same level, the desiccant variety needs emptying two or three times daily, in a 24 hour period, there was barely a cup of water in the compressor type.

mike

That's what I said in my post, without a doubt more expensive to run (at least double), I happened to put my desiccant one in a closed room at 7 degrees yesterday, after 2 hours of dehumidifying, the room was at 11 degrees and the water container nearly full, which quite simply a compressor couldn't achieve. I tend to prefer to use mine in rooms I plan to use, it's a pretty good space heater. I never use this one in the summer, when I don't need warmth.

I'd agree that you get more water in air at a higher temperature, however you've got to think where this water comes from, e.g. a shower or kitchen where you're not in an equilibrium situation, and of course atmospheric pressure affects the amount of water. The mathematics starts to get quite complicated (you have to include atmospheric pressure), before you start to introduce the desiccants own performance, which although affected by temperature and humidity, generally will remove almost as efficiently at lower temperatures and humidities, certainly the sort of humidities caused by cooking or having a shower, so even if you have less water contained in the air, the desiccant still removes almost as much water in a given time. It's important to remember the cost of running the desiccant dehumidifier is directly proportional to the amount of water extracted, so if it extracts at a lower rate, the heating of the desiccant is reduced, this is by far the most electrically expensive part of the equation (and quite the reverse of the symptoms of a compressor dehumidifier, where the expensive part is the compressor, and this runs for longer the lower the extraction).

In the absence of proper scientific experimentation (and willingness to do the maths), sticking the two different systems side by side in the same room, proves all I need to know. Desiccant types work better in lower temperatures, but the cost is much higher.

It seems rather dubious to me that all the manufacturers all quote dehumidifying capabilities at what is frankly an almost unachievable temperature in the UK, the validity of those figures is about as useful as measuring the acceleration of a Ferrari in free-fall dropped out the back of a Hercules.

mike

Go to Home Bargains, go to the cleaning isle and buy a Mould Spray called KillRock. It's £1.99 all you do is spray the Mould and it disappears after 5 minutes you don't need to scrub it or anything. Ours never came back!

My vote for 12l one

What is the best and most effective and cheapest to run solution to take damp from a bathroom? Anyone have any good advice? My bathroom is starting to get little mold patches in my bathroom and I want something to stop it before it spreads.

nice, thanks

Wish I had read this before I bought the 12l compressor one last week. Do you think it would help locating the dehumidifier next to the radiator? This is in my dining room with open conservatory.

The rub is that desiccant ones seem to cost double to run, as shown by user tests.

Cold air by its nature does not hold much water so the desiccant too removes less when cold, it also using more electricity to heat the colder and lesser amount of water.

That 275W spec is likely 200W when running, 265 the very short startup drain for the compressor. A 16l desciccant is likely to be 500W.

Bought one of these on Saturday. Absolutely brilliant. Highly recommended

Have to say, when i researched this before purchase I ended up going the dessicant route. Bought an EcoAir Classic from Aplliances Direct (cheaper than Amazon after I'd taken out the Which trial which gave a £20 discount) and would,'t be without it now. We live in a bungalow that was definitely suffering from damp (75%+ himidity in some rooms). Ran the EcoAir on full setting for a few days and now the 'base' reading is around 45% - 48% in all rooms. We only run it (on lowsetting) for 2 hours a day now and we simply cannot believe how much water this machine has literally sucked out of our air.

Could anyone give me an idea of how loud these things are. I currently have the passive tablet style ones.

I realise its hard to evaluate sound with words but for example if its in the next room (eg hall) at night would you hear it? Or maybe it's like a small fan noise etc? Thanks!

Thank you for taking the time to explain, this was a very useful post !

Although I'm still unsure if I should buy a desiccant or compressor type dehumidifier, as our house is usually around 16+ degrees. Heating a room during or just before using a compressor dehumidifier might be a cheaper option in the long run.
I'm also thinking of giving my young tenants a dehumidifier, as they don't seem to open the windows at all during winter, and there is far too much condensation on the windows.

so you guys who have this dehumidifier rate this one do you? ive already one but looking for another as the other one is getting old.

Regardless of the comments above I have two Dimplex compressor type dehumidifiers and both work fine even in cold weather, which is the only time I need them running.
I have one in the conservatory which is north facing and separated from the house by patio doors and very cold, without the dehumidifier the glass runs with water in winter and I get black mould appearing on the plastic.
The second I have in the kitchen which was extended and has a glass conservatory roof, not cold as its part of the house but still get lots of condensation on the glass in winter without the dehumidifier.
I have both fitted with the continuous drain option and both work great and cure the problem for me even in the very cold conservatory, it's most certainly not wishful thinking.

One other point worth mentioning. I have two dehumidifiers one compressor type and one desiccant type. I cant use the compressor type upstairs as the vibration against the (carpeted) floorboards creates a horrendous din. No problem with the desiccant type though.

I've heard from a few comments above dehumidifiers are expensive to run?...

After I'd done a little research before purchasing mine about a year ago, I was reading they WEREN'T expensive to run...

16 degrees is a difficult temp to decide on, compressors won't be as efficient, but this is the point where they start to extract similar amounts for the same power as a desiccant - but only if the compressor type is a high end machine, your cheap ones from Screwfix and Aldi are not the most efficient, so if on average your house is often higher, then you can probably choose either, and expect them to cost the same. The main advantage to desiccant at this temp is that it will be quieter and will warm the room up a degree or two. If the house temp is 20 or higher then the compressor type starts to win out, but will usually make more noise.

Most of my rooms are lower than 14, desiccant is a clear winner.

I've never found heating a room temporarily that effective, I've got a wood burning stove, so I heated my dining room to 20+, and ran the compressor dehumidifier, it extracted better, but still nowhere near the levels the desiccant type managed in the unheated room. I suspect that's because the heat drops the relative humidity significantly, and therefore it's harder to get water out.

For tenants, you're not paying the electricity bills, but you would cover the cost of fixing a broken dehumidifier, in this instance the desiccant type is definitely a little more fragile and the filter requires regular cleaning. I would probably go for the compressor type.

I should add I've got 3 compressor dehumidifiers, two Ebac and one Aldi, I noticed it was taking days to fill the tanks, which according to the spec. would need emptying daily, hence looking into the science.

mike

We also have an EcoAir DD122 - Desiccant type and its completely transformed a cold bedroom with poor heating and condensation problems. Its brought the humidity down from the high 70's to high 40's/low 50's and its set to auto, running maybe 6 or 7 hours out of every 24 and it fills its tank up at least once per day.

Mike, is your Aldi one the LE 2013 or LE 2014, 20l? It would be good to know as in another thread, that unit seems to be almost the same as the Meaco 20l one (but without the mechanical louvre). Same base unit though.
Many thanks for an update!

Thanks OP, ordered and heat added.

I assume this is a compressor dehumidifier?

This is a bargain. Bought a dehumidifier recently and the cheapest I could find a 16L model was about £150.

Thanks for the replies telling me to open a window in my bathroom but my bathroom has no windows.

Simply astounded by the amount of money people are prepared to spend on equipment for damp houses. It's clear from the comments that the majority of those that need this product either a) have leaky roofs/walls and/or b) don't heat their houses enough.

Not pointing fingers and naming names but "most of my room rooms are lower than 14"? It's well pulicised the press that living areas should be a minimum of 18C before you start getting health risks such as hypothermia and pneumonia - the damp caused obviously contributes to this. Sure, a pantry behind a closed door doesn't necessarily need to be this warm but bedroom, bathrooms, kitchens etc need to be warm and stay warm. Let them drop a little downstairs overnight if you like, whilst you're wrapped up in bed, but warm them up again in the morning.

Most of these compressor devices use 150-200W of electricity - that's going to be about £15/mth of electricity just for dehumidifying a room that needn't be damp. Swap it for a dessicant devices, required because you refuse to heat your room, and you're talking more like £30/mth - just to dehumidify - you could probably heat your whole house for that.

I just don't get it.

Nothing personal, but this site is about saving money - buying a dehumidifier isn't a good way to do that.

Reading through the thread - couldn't decide if to vote Hot or Cold :P (voted Hot for me as just ordered).

I voted cold, like your house.

ro53 is a cultrure breeder in summer!
Not everyone needs a dehumidifier.

BTW, my Aldi is far better than my Dimplex. No, its maybe not more effectve than desiccant for cold empty rooms in winter, but even there, at one third the power, its still a fair deal on your bills.

I don't have one. It cost me nothing and the running cost is zero.

I have no damp or mould.

​Thanks Mike this is very helpful. appreciated. :smile:

​I checked on Amazon and there seems to be a few by different companies. I don't have a home bargains near me. Can you provide me the company who makes it please and thank you by the way :wink:

http://www.kilrock.co.uk/about.asp

Blast Away Mould Spray
Effectively removes stains caused by mould and algae.
This professional formula has a bleaching action. Ideal for all interior surfaces.
In bathrooms, kitchens, basements etc. Also effective outside the home.
Treats approx. 3 square metres of wall or 8 square metres of tiled surface.
500ml

No, it really isn't that difficult and there should be no need to spend hundreds of pounds on equipment and more on running costs to resolve.People have already confirmed in the thread that they clearly don't heat their rooms sufficiently to even be within the recommended parameters for healthy living.

Having an old house is no excuse. People live in Victorian houses, even castles, they don't need dehumidifiers. You just need adequate heating and ventilation - sticking some socks in a ventilator brick to reduce your drafts is not a solutions, buildings need to breathe.

Op

You missed 3% Quidco
3.15% TCB

Price drops another £3 if you apply

You can suspect, and I'm quite sure you will also be correct. I don't want my kids to die prematurely from respiratory disease.

I've got a highly efficient heating system but I doubt even that can compete with people who are prepared to inadequately heat their homes to the point of excess humidity and damp.

You should go selling humidifiers to Eskimos, I'm sure you'll find a few idiots out there.