Been running 2 of these since just before Xmas. Prompted by SWMBO having to sleep on a hospital bed in the lounge.
No condensation since using them and they are pulling about 1L every 4 days between them.
Meanwhile our BFO dehumidifier (compressor etc) is pulling about a litre a day from the front room - washing dries quickly in there.
We had an issue with mould in the wardrobe in our bedroom, particularly on leather (handbags, belts, gloves, etc). The internal volume of the wardrobe was about 3.5m^3. A humidity meter measured around 73% RH in the wardrobe.
I got a small peltier dehumidifier from Argos, and left it in the wardrobe with the doors closed. It removed 125ml water a day (consuming
22.5W/h). Over time, the RH decreased until now it is consistently under 60%. In the 4 months it has been running, 12 litres of water have been collected. Mould is no longer a problem.We also run a Dimplex compressor dehumidifier on occasion in the spare bedroom (unoccupied for months, yet always getting small amounts of mould on external wall corners at ceiling level). At the start, this was removing over 1.5l/day, now it's down to less than 0.5l, and the mould has gone. But why is there moisture appearing in that room, even though we keep the door closed?
You can do all sorts of sums. However the TL;DR is that the water being collected and poured away is *not* going anywhere else.
I shudder at all the people who think heated airers are the DBs. Where do they think that moisture goes ?
Yep. We have a condensing tumble drier and it's remarkable how much water is in the tank at the end.
Check clothes are aired before putting in wardrobe after washing.
Outside walls can be a problem, especially if you don’t have cavity insulation.
When we aren’t using the motor home, I try to ensure the temp is at least 7 or 8 degrees, higher during the day, and run a small dehumidifier. We open all the cupboard doors. No really practical in a house. Moisture in motor homes is a common problem - while not sealed they are small and you cook, breathe etc. all in a confined space for weeks at a time.
Would they be the same people who think that any ventilation is just a draught?
Out through the vent in the wall?
Down the drain for every condenser washer/dryer I've owned.
All washing in the cold months is tumble-dried to "cupboard dry". If it was aired it would be more likely to pick up moisture!
I was concerned about the wardrobes being on an outside wall, so although we have CWI I put 30mm polystyrene insulation on the wall inside the wardrobes in the main and spare bedrooms. I think the problem is that there are two of us breathing out water vapour for many hours, although how it gets through the closed wardrobe doors I don't know.
Superinsulated homes in Scandinavia don't seem to suffer mould problems do they? How do they avoid it?
MVHR systems so you're always exchanging stale/moist inside air for fresh outside air, while retaining heat. Even if it's wet outside the cold outside air carries little humidity so its RH drops as you warm it up. You can also dehumidify it on the way in if you want.
Theo
More insultaion and heating than you could ever get in a motor home...
Do yourself a favour & lose the peltiers, use the compressor machine. Peltier energy efficiency is pitiful.
Moisture comes from breathing, cooking, bathing, laundry & leaks. Houses failing to get rid of it are down to either too much input or some fault inhibiting elimination. That doesn't answer your question, no-one can with info you've given, but it does move one step closer.
It's about a quarter that of a compressor dehumidifier, but that's not the primary concern. Firstly, it's 9 times smaller than the Dimplex, and there's not a lot of room in the wardrobe. Secondly, it's almost silent
- the fan is imperceptible. When the Dimplex compressor kicks in, you know it; it really is not suitable for an occupied bedroom.
The peltier consumes 22.5W/h. The Dimplex is said to use 410W, but that would be intermittent. Would it only be on for 1/18 of the time of the peltier? Perhaps, but as the peltier removes enough moisture to keep the RH below 60%, why be concerned about its inefficiency? It's under a fiver a month, and it wouldn't be in use all-year round anyway.
The question was somewhat rhetorical. I'm pretty certain there's no rising damp as the mould only ever appears at ceiling level where there's little or no air movement. Fortunately, it's easily removed with bleach.
However, the Peltier effect machine is light enough to carry upstairs, which would be a struggle with the compressor machine. It is also low voltage, so I can use it in the bathroom, where I use it to dry the liners for my compression stockings, which cannot be wrung or heat dried. If the bags of absorbent clay had not already removed the condensation from my car, I would probably use it there too.
Usually I would put a dh in the room rather than in the wardrobe - the latter might reduce its run time somewhat, so you might not lose out so much on energy use. Peltiers are typically 12v 4A, about 48w, and run nonstop. W/h is meaningless.
Rising damp is very rare. Mould at the top of the wall is quite likely to be faulty rain handling.
The energy used will also go towards heating the room so not wasted, especially if only used in the colder months.
Also there's a virtuous circle: heat into the room raises the air temperature, which encourages more water to evaporate, which means the dehumidifier can extract more water.
As a result of this thread I just bought one:
It's been running a couple of hours and only got a few drops so far, so not exactly quick. It claims to take 39W, which I have yet to measure.
While it's not loud, the fan noise is enough to be annoying to sleep with, even in the next room. So I'm going to have to look into replacing the fan with a quieter computer fan. Also you can't control it via the mains plug you have to press a button on it to start, so I'll probably have to link that out. At the end of the day they're just a fan and a peltier device, so skipping the electronics and giving them about 12V (haven't checked the internal PSU of this one yet) and they should do the job... slowly.
Theo
50w of heat isn't going to make any difference. A fan could.
check the peltier temp before & after, any old fan is not going to do it.
Peltiers should not be switched. Leave it running until it's no longer needed. Switching them kills them preaturely, and as you've already found their performance is misrable enough when run 24/7, let alone when off much of the time.
what electronics?
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