Condensation On Windows

Innys

maninthestreet wrote: »

Eh? Cold air cannot retain as much moisture than warmer air.

The external humidity where I live in the South East is currently over 80% - probably because of the amount of rain in the last couple of months. It's not that high in the summer.

It doesn't matter whether the external air is cold or warm. If it is full of moisture, that cold moist air will come inside when you have the windows open. The moisture will then condense on any cold windows and walls.

iris

Gloomendoom wrote: »

Ha ha! I was intrigued so Googled it...

10 eco products you don't need

ETA: The Which test seems to based on heat insulation rather than condensation prevention.

We only installed it to prevent the condensation, not to prevent heat loss, which is what the OP was having problems with.

All I can say is it works.

loracan1

Innys wrote: »

Get a dehumidifier.

Don't open the windows (in winter at least) as the air outside is likely to be more humid than that inside.

I only ever get condensation when I keep windows shut...

WestonDave

Innys wrote: »

The external humidity where I live in the South East is currently over 80% - probably because of the amount of rain in the last couple of months. It's not that high in the summer.

It doesn't matter whether the external air is cold or warm. If it is full of moisture, that cold moist air will come inside when you have the windows open. The moisture will then condense on any cold windows and walls.

Sigh! The reason the air outside is at 80% humidity is because its cold - cold air can hold less water than warm air - so if the air outside is say 5C it can only hold a very small amount of water before it is saturated (100%). Indoor air at 20C can hold a lot more water so with the same amount of water in it as the outside air it will be much further from saturation - say only 50%.

To give you some exact figures from a chart - if you bring in 80% humidity air at 5C from outside, and heat it up to 20C inside your house, its relative humidity will fall to around 30%. Bringing it in at 10C and 80% would get you just under 45% when heated. Its counter intuitive in many ways but the irony is that the worst time to open the windows to reduce humidity is during a summer thunderstorm - then the outside air is warm and saturated so bringing it in and not heating it means you are then bringing in a lot of wet air.

If your theory worked, car windscreen demisters wouldn't work - in a car you draw in air from outside (typically when its raining), pass it over a heater element and then blow it on the windscreen to dry it off. By bringing in that cold air and heating it, you increase its ability to hold moisture, it has spare capacity and so absorbs the moisture from the inside of the windscreen.

2Sheds

iris wrote: »

We have had a problem with condensation on our double glazed bedroom windows for years.

However, my husband has just fitted 'Stormguard' window insulation and I am pleased to say 'it works'. No more having to wipe the windows every morning:j
Give it a try. We bought our kit off Ebay for £5.99 delivered. It's a bit fiddly to install, but it really does work.

For that price worth a try and if it does the job I can turn off the drimaster

27col

I never ever get more than the very slightest mist of condensation occasionally and the windows are never opened. Certainly not in winter. It is not a question of lack of ventilation but of lack of heat. If the air in the room is cool then you will get condensation, if the air in the room is warm then you won't. It really is as simple as that. Of course, this supposes that there is cavity wall insulation as well as double glazing.

a&akay

maninthestreet wrote: »

It's caused by the occupant(s) of the bedroom breathing!

This is the reason. We've bought a Karcher wv50 (google it) and it's amazing how much water you collect in the container. It also cleans the inside of your windows each time. Otherwise open the windows to ventilate and lose £££.

sgoode

I've also just bought the Karcher WV50 and it makes the morning chore of wiping the windows down so much easier.

I've tried a dehumidifier and it didn't make a great deal of difference.

We have double glazing but it is quite old and we have thick floor to ceiling curtains so I think the lack of air circulation must be why we have excessive condensation.

Badrick

Dry your window, wipe with neat washing up liquid and buff off, probably would need re-doing weekly.
Simples.

Dustykitten

We too have lots of condensation, on the double glazing too. DS3's room is tiny and he gets the most as I guess there is less air to hold his moisture.

I did read somewhere that as the water will go to the coldest surface (usuallly) the windows it stops it from damaging walls etc in terms of mould, peeling wall paper so there is a bright side to it.