Avoiding condensation in such cold weather

richardc1983

This should explaini further look at the example further down: House A & House B etc.

http://www.windowstoday.co.uk/condensation-explained.htm

Fire_Fox

Is there a through draft in the bathroom (window plus extractor) but not in the kitchen?

olly300

Fire_Fox wrote: »

Damp air, condensation and mould is a problem in many flats as they just don't have the natural ventilation of houses (windows to one aspect only/ front doors leading onto internal corridors/ internal bathrooms and halls).

All the flats I've lived in and all my friends/family who current live in flats have windows on at least 2 aspects, some have had it on 3 aspects.

Strangely I've only been in houses that have had bathrooms without any windows. Even my friends who have en-suite bathrooms in flats have a window in the bathroom.

Fire_Fox wrote: »

Even if you didn't have cold spots on the walls, the water would simply settle on the window glass instead as you'd still have high humidity. It's the water/ ventilation that needs addressing not the insulation as most flats are fairly well insulated by their neighbours.

Depends if you are at the end or not.

The problem in the OP case is the kitchen is not heated at all and is too cold.

That means regardless of what they do unless they can raise the temperature of the kitchen, if they cook in the kitchen on the hob they will generate lots of condensation.

My own kitchen didn't have a radiator in it until 2 years ago. However the lowest temperature without the heating on, using a thermometer, in my flat is 15 degrees. My kitchen is West facing so gets warmed by the sun and the outside and internal walls are cavity walls. There are no neighbours next to my kitchen. All I had to do when I was cooking (and still do ) was open a small window and I had no condensation problems. In addition I also kept (and still do) the bathroom door closed.

When I lived in a friends' flat who had storage heaters, her kitchen didn't have heating. However as her kitchen led on to her living room she removed the door to the kitchen so the living room storage heater was heating the kitchen as well. Again all we had to do to keep condensation down was keep the bathroom door closed and open a window when cooking. The kitchen and living room had windows on 3 aspects and were not double glazed.

I've had worse problems living in places where the bathroom had no heating.

In short OP if you cannot heat the kitchen then you need a dehumidifier.

neas

We use a DEM10 dehumidifer (delonghi one).. it extracts 10 litres a day and requires emptying once it has 2 litres in it. They are around 100 quid.

Got ours on ebay for 90 quid delivered (offered some guy 5 quid off his buy it now price etc).

Its a good dehumidifier... but as its a cheaper make (or maybe all dehumidifers work similaryu) if its too cold.... the water it is 'condensing'/cooling will ice up and freeze it up..so it switches to a 'fan/heat' mode to defrost itself. This occurs more often if its colder in room.

Just a thought. Also suggest you buy a hygrometer (one people use to grow d rugs lol)... they about 7 quid on ebay... environlite is one we got.. works well.

50-55% RH is ok... 60-65% is getting too much and anything above 70% will be a perfect place for mould to grow.

Our rented flat has similar problems (not kitchen) but mornings we would get condensations and mould on a few clothes.... so we got the DEM10 and dehumidifer bags.. to help. So far doing ok.... also we heat more.

Fire_Fox

As stated most flats are well insulated by the neighbours - even if they don't have another flat both sides, they generally have one above and/ or below. My flat never seems to fall below 12C despite minus whatever outside. :T You cannot assume the lack of heating is the only problem in the OPs case - they are obviously breathing, showering and admit to drying cloths indoors.

Many on these boards claimed lack of heating for my flat but having used constant low level heat since before Christmas, there has been NO discernible improvement in the condensation. :mad: In my case the problem is poor ventilation combined with metal window frames: confirmed very recently by discussions with an engineer and an architect (both friends of family!).

poppysarah

kai_lani wrote: »

Appreciate what you're saying and as I say, I do the main drying at the launderette, it's just I can't do the launderette after cooking and need to make some effort to dry out the towels to minimise the wet stuff still in the flat - we're talking 3 damp tea towels, the outdoor kit that's wet stays in the garage and then usually goes back on, still damp and a whole lot colder brrrrrrrrr................

Get one of those spinners to dry the washing more than the washer does.

kai_lani

@richard - thanks for that, i'lll look it over later tonight

@FF - bathroomhas heating, but no draught as such, just an open window, albeit only a 1/3 opener not full opener. And we're in a top floor corner flat - one below VERY cold communal area outside front door. And you're right, there is a little drying indoors, but it really is only minor, and only in the bathroom. I appreciate that even this will increase humidity across the whole flat despite my obsession with keeping doors closed to maintain heat in the heated rooms.

@Neas - thanks for the quick and simple explanation - the hyro thingy/clock/thermometer is reading 55%, 12d, 17:15 not too bad by your post, gotta work out this relative bit though.


I think the plan should be, a dehumidifier for a while and see how that goes, along with being a bit less anal with keeping doors closed - let the heat spread instead of keeping it only in the "living" rooms.

richardc1983

55% relative humidity at 20-22C is not a problem or the warmer u get.

But at 12C if thats what you mean then the air cant hold all that so it goes on your walls.

I dont think you have a damp problem just need to get that room heated.

Nixer

You can get dehumifiers that have a laundry mode which is useful if you have to dry clothes in the flat. In a warm room mine will get a load of towels dry in about 4 hours. I have a Prem-i- Air but not sure of the model (in a previous condensation thread I said it was an X Dry but it isn't). It has a tube which you could put into bath or basin (or maybe a covered bucket) if you don't want to empty it but I wouldn't need to empty mine in one session usually.
I did do my sums when I got it and I think I worked out that it was marginally cheaper than using a tumble dryer, but it's obviously not quite as quick.

It might be worth trying to borrow or hire one to see whether it will help with the kitchen - it will work better with warmer air but it will still work in the cold.

neas

richardc1983 wrote: »

55% relative humidity at 20-22C is not a problem or the warmer u get.

But at 12C if thats what you mean then the air cant hold all that so it goes on your walls.

I dont think you have a damp problem just need to get that room heated.

Sorry to contradict what you are saying but relative humidity RH... is dependant on temperature... hence why all hydgrometers have a temperature reading.

from wikipedia:

The relative humidity (Φ) of an air-water mixture is defined as the ratio of the partial pressure of water vapor (ew) in the mixture to the saturated vapor pressure of water at a prescribed temperature.

Damp is a problem because if you have 50% RH at 20-22 ºC... but then the temperature drops to 10 ºC (i.e. in OPs kitchen) then the relative humidity there will be up to 60-70% compared with the 'hot' room... which will be a nice environment for mould. So although the water in the air is eventhroughout the building... living rooms and bedrooms (at 20ºC) will not get mould... but the cold room (at 10ºC) will.



Also the even if you have a RH of 50% at 20ºC... or even 30ºC.... because your windows/external walls are at 0ºC when the water vapour touches the window it will condense (as you put it there RH at that point will saturate i.e. go above 100% and form to water)

I think we saying similar things just in different way :P. In winter with cold windows you will always get a bit of condensation unless you get really low Relative humidity. With OP its worse because room is cold and produces lots of water vapour to start with.