Windows to solve condensation problem?

[freddiemercurystwin]

/sigh

So your solution is what? Fit new windows? Dig off the reveals to squeeze some foam in and re-plaster etc? Fit new DG units?

One or a combination of the above may work. They may not. But they are all more expensive than fitting a couple of vents.

Buildings still need to breathe even in 2014. Though the products/technology may have evolved, the physics for allowing that to happen has not.

 

[AronSearle]

So your solution is what? Fit new windows? Dig off the reveals to squeeze some foam in and re-plaster etc? Fit new DG units?

No, my advice to the OP, who asked whether he should get new glazing or new frames as well, was to get an IR thermometer.

Knowing surface temperatures will help evaluate how much of the problem is due to the windows.

And certainly foaming around the windows, if this is missing, could make a significant impact on managing condensation.

But they are all more expensive than fitting a couple of vents.

But vents may not provide enough ventilation to remove condensation if surfaces are excessively cold.

Ventilation will solve all condensation problems, but sometimes the level of ventilation required is excessive or unreasonable.

Buildings still need to breathe even in 2014.

Yes?

 

[ronniecabers]

But new windows or glass will not cure the problem....it will just move it to the next coldest point in the property. You also need to look at levels of humidity in the property , in general, and thus quantity of water vapour.

No one thing will solve the problem completely, in fact you will never solve condensation completely, only manage it.

 

[footprints]

We had tenants in a 1 bed flat we used to own, the first couple had no problems the second in the same flat had windows running with condensation, it has to be down to life style, or perhaps the second couple were "more active" during the night

We supplied a dehumidifier (we used a Delonghi ) and it solved the problem, OK you have to factor in the running costs, but that is an answer, unless you arrange a mask to breath through a hosepipe run to outside at night

 

[stork]

Thanks for the replies and discussion.

The windows don't have trickle vents, although there are three other upstairs windows which do. They're in an extension which is built to more modern standards (2002 I think). In those rooms, one of which is used full-time as a bedroom, we still get a small amount of condensation on the window, but much less than in the other bedrooms (even the spare one which is only used occasionally) and bathroom. We don't get any condensation/mould problem on the window reveals in the newer part of the house.

We do use the night vent settings on the windows in question, although on cold nights the heat loss becomes excessive. The heating goes off overnight, and no doubt this encourages the formation of condensation by the morning as the air cools and needs to dump its moisture somewhere, and the window and reveal surfaces cool down. But we don't really want the heating on all night either.

I have an IR thermometer which might work -- it was really intended as a body temperature thermometer but I'm sure it has a wider useful range.

I agree that more ventilation is the cheapest solution in terms of up-front cost, but of course this could then demand more heating.

 

[crank39]

The condensation threads could run and run and run much like the airplane and conveyor belt thread, in truth and in fairness to all the replies its going to be a combination of everything that's been suggested

 

[foxhole]

Good balanced ventilation is the only solution to condensation, physically impossible to get you house structure to a temperature where condensation will not occur[increase in temperature is directly related to the amount of moisture it will support]. Also ventilation prevents spores settling and mold.

 

[stork]

I've taken a couple of temperature readings this evening, will try to do some in the morning over the next couple of days too.

Outside temperature is about 2 C. Inside of glass just under 13C, inside of frames 14-16C, reveals just under 13C. Room is comfortably warm, probably 19-20C. By the morning, everything is likely to be a bit colder.

This is suggesting to me that the frames aren't so bad, but that the reveals may be less good.

 

[freddiemercurystwin]

AronSearle shall be along to digest this valuable information and will evaluate how much of a problem is due to the windows.

 

[AronSearle]

I've taken a couple of temperature readings this evening, will try to do some in the morning over the next couple of days too.

Outside temperature is about 2 C. Inside of glass just under 13C, inside of frames 14-16C, reveals just under 13C. Room is comfortably warm, probably 19-20C. By the morning, everything is likely to be a bit colder.

This is suggesting to me that the frames aren't so bad, but that the reveals may be less good.

13c is a problem, you will find it hard to avoid condensation at that temperature without leaving windows on the night latch or turning up your heating, bearing in mind that it may get colder than that in 0c weather. It might be worth doing some poking about to determine if there is insulation around the window frame, or as you said if the brickwork is returned in. Are there easily removable plastic trims?

14-16c is not great, but trickle vents should almost certainly provide enough ventillation to avoid condensation on those surfaces, new glazing within the frames should easily maintain higher internal surface temperatures, but this is where you might find the payback unpallatable.

physically impossible to get you house structure to a temperature where condensation will not occur

Rubbish.

At *80%* humidity and 20c, surfaces need to be 16c or lower for condensation to occur (80% humidity would be fairly grimm, but just saying as an example).

It's only our **** poor housing stock and the quality of work and fittings that make condensation such a problem. Far too many houses have very poor insulation detailing, resulting in lots of thermal bridging and cold surfaces.

But new windows or glass will not cure the problem....it will just move it to the next coldest point in the property.

Assuming there are colder points for it to move to.

 

[freddiemercurystwin]

Sooooooooo in a roundabout fit some trickle vents and see what happens?

 

[AronSearle]

Sooooooooo in a roundabout fit some trickle vents and see what happens?

indeed.

Try re-reading my post, you clearly didnt read and consider all the points properly.

 

[stork]

So, the temperatures first thing this morning, with an outside temperature about -1C, were:

Glass: 10C or slightly under (thermometer only reads down to 10C).
Frames: 12-14C
Reveals: 11-13C

My first step will be to improve the bathroom extractor fan. The current one is feeble and it has a most bizarre ducting arrangement (through ceiling, right angle into fan, then 180 degree turn out of the fan followed by another right angle towards the soffit cavity, right angle down into the soffit cavity, right angle along the cavity, right angle back into the wall cavity, right angle down inside the wall cavity, right angle to the grille on the outside of the wall!) (I'm not quite sure how it gets through the wall cavity, but it's definitely in there, and the wall is intact from both outside and inside).

That should reduce the moisture load on the upstairs rooms to some degree.

Next step probably to consider retrofitting trickle vents to the windows -- maybe experimenting with night vents overnight would be a good idea first. Then consider cost of replacing sealed units or whole windows with or without cavity insulation/closers.

Heating is about as high as I want to put it.

Thanks again for the comments.

 

[AronSearle]

You could replace the extraction for one with a humidity sensor.

what you need to remember about trickle vents is that they work poorly when temps are near 0c, because in this country cold weather normally goes hand in hand with low winds.

Surfaces sitting at 10c will be really prone to condensation, and bearing in mind the above, you will need to be fairly proactive to avoid condensation.

 

[JohnD]

they work poorly when temps are near 0c, because in this country cold weather normally goes hand in hand with low winds.

Although in UK homes, moist air will rise (water vapour is lighter than air) and will try to escape through any gaps at the top of the house, and cool dry air will tend to enter at the bottom.

This can be strikingly illustrated if you open your loft hatch in cold weather.