Condensation in the house

[Another John]

I'm noticing condensation a lot more these days: all windows in the mornings covered with it, and us having to clean it all off.

Now, it MAY be that it's simply that I'm noticing a lot more than I used, having retired only a year or so ago (in the past I'd be out of the house before any curtains were drawn).

Or, it may be that our house is now more hermetically sealed than ever before: roof insulation maxed up, cavity wall insulation, a porch added to the front, and all windows are double glazed (although some are old - DG units inserted into wood frames).

IS there anything sensible that I can do to improve the situation? Apart from not heating the house, opening windows, not cooking (gas here), etc. ?

BTW we try and keep our CH down to about 17, and it goes on at 0720, off at 0930, on at 1630 and off at 2030, with a few boosts during cold days when we're in.

I was wondering about acquiring a dehumidifier, but that might be going too far?

Cheers John

[meow2222]

A dehumidifier is often the practical option, unless you can reduce water vapour output somewhere, eg by using pan lids and low heat in cooking, drying clothes outside or in a condenser dryer etc

NT

[Chris Hogg]

I would certainly recommend a dehumidifier. We have two. But sensible steps that you can take before that are to reduce the amount of water vapour and steam being generated inside the house. Drying your washing indoors produces a lot of moisture vapour, as do bathrooms/showers, and cooking. Particularly bad are portable room heaters that run off bottled gas or paraffin. The rule of thumb I use for these is that every gallon of liquid gas or paraffin you burn, puts a gallon of water into the atmosphere as steam.

[Dave Liquorice]

Pragmatic IMHO, a house with suffcient air changes to stop it becoming stuffy shouldn't suffer condensation. Though I'm not sure what the OP feels compelled to clean it off, it'll go soon enough as the window warms up with the curtains drawn.

And use a kitchen and bathroom extractors. The cooker hood here when we moved in was a recycler and the windows in the kitchen and adjacent open plan study area would pour with condensation with almost any cooking. Converted it to a vented hood and one would really have to go some with an open pan of boiler water (say pasta) to get any condensation on the study windows. The kitchen ones still would but not pour with it, just a heavy misting.

[stuart noble]

Our CH is set slightly higher than that and comes on an hour before we get up. There are days when the windows, and the car windscreens are running with condensation, but I can't say it's often. Typical late Autumn weather I would have thought

[Brian Gaff]

Well you need the humidity. Sounds like the windows are not that good at insulating to me. I see this on frames of some old windows but not on the double glazed units. Some ventilation usually fixes this, but as you say, how to ventilate without making a draught and making it colder. Brian

[The Natural Philosopher]

most dg has trickle vents. Open them

[critcher]

critcher said............... turning heating on and off serves no purpose at all, if your house cools down it takes the same amount of heat to raise the temp as it would have to leave the heating on and maintain the temp.

[John Williamson]

Experimentation says otherwise.

[Bob Eager]

Wrong. Because while it's maintained at the upper temperature, it's losing more heat per minute than it is when at the lower temperature. Thus more heat input is needed.

[Paul D Smith]

...snip..

Years ago I owned a small dehumidifier because that was the only thing which successfully kept the condensation down in my flat.

If you get one that captures the water, you can use it in the iron (assuming your tap water is hard like in London). Offset the cost a little.

Paul DS.

[Chris J Dixon]

Not if it obeys the laws of physics.

Chris

[polygonum]

I must admit, it is amusing to think of the opposite - if it did take the same regardless. A building unheated for a few years or centuries would take an unbelievable amount of energy to re-heat! Perhaps the 350 degree C ceilings would be real instead of a typo?

[Lee]

We have our CH on 24/7 @23C during the day and 18C at night (using a prog stat) and see the same thing. Doubt the CH temp makes much difference.

[Man at B&Q]

It's when the curtains are drawn that the condensation occurs - on the windows due to the colder zone and lack of circulation created by the curtains.

MBQ

[Man at B&Q]

like the windows are not that good at

Most *new* dg does. Hardly any older stuff does IME.

MBQ

[dennis]

Its amazing how many people believe stuff like that. Education standards are really low these days.

[critcher]

critcher said........... can you explain those laws of physics chris ?

[Andy Champ]

Heat loss is a function of the two temperatures. Radiation, for example, is related to the fourth power (squared squared) of the temperature difference.

The bigger the difference the more energy it takes to maintain it.

If you let your house cool down overnight the heat loss from the house is less than it would be if you kept it warm, because the temperature difference is less. As it cools down you are losing heat you'll have to replace in the morning - but as the difference is less the amount lost is less. In the morning the boiler will have to work hard for an hour or two to heat it back up, but this will still be less gas than it if had been running gently all night.

Andy

[Broadback]

I cannot remember the figures now but during the war the heating was off in Westminster Abbey, it took months if not years to get the temperature back up again when eventually it was switched on.