Condensation in and on double glazing

kuepper

2 months ago I had new windows fitted in kitchen and bathroom and a new back door with glazing that opens into the kitchen. Now the weather has got colder I've noticed condensation on the new windows and door and even when I wipe it off it soon recurs and I can see it glistening where the rubber seal meets the glass. It's always on the lowest part of the glass.

I've read elsewhere that this is normal though I didn't expect it - I've had trickle vents open all the time and as I live alone I don't generate much steam. 

However I'm concerned that after only 2 months there appears to be condensation on the inside of one of the glazed units in my bathroom, photo attached. So does the unit need replacing or the whole window? I wondered if water from the condensation could have weakened the rubber seal but it shouldn't have been able to get in anyway should it as the unit is supposed to be a vacuum  so is it a manufacturing fault?

Chickereeeee

If by 'inside' you mean there is condensation within the double glazing unit, between the panes of glass, then it has failed, and needs replacing. Just the pane that has failed, not the whole window. (FYI, it is not vacuum between the panes, but a noble gas with large molecules).

It is unusual  to get condensation on  a double glazed window, unless it is in a particularly steamy or cold room.

Mark_d

Chickereeeee said:

If by 'inside' you mean there is condensation within the double glazing unit, between the panes of glass, then it has failed, and needs replacing. Just the pane that has failed, not the whole window. (FYI, it is not vacuum between the panes, but a noble gas with large molecules).

It is unusual  to get condensation on  a double glazed window, unless it is in a particularly steamy or cold room.

I think you're generally correct though I have often observed condensation on the inside of double glazed windows where there has been inadequate air circulation.  If this is the case then keeping the curtains open as much of the time as possible should resolve the issue.

Chickereeeee

Mark_d said:

Chickereeeee said:

If by 'inside' you mean there is condensation within the double glazing unit, between the panes of glass, then it has failed, and needs replacing. Just the pane that has failed, not the whole window. (FYI, it is not vacuum between the panes, but a noble gas with large molecules).

It is unusual  to get condensation on  a double glazed window, unless it is in a particularly steamy or cold room.

I think you're generally correct though I have often observed condensation on the inside of double glazed windows where there has been inadequate air circulation.  If this is the case then keeping the curtains open as much of the time as possible should resolve the issue.

Yes, I was going to add that. Curtains, or poor air circulation generally, allows the static air near the glass to lose heat, even through DG, and go below its dew point. Then, condensation forms.

kuepper

I don't have any curtains in my kitchen or bathroom. Both those rooms are to  I never had any condensation problems with my old double glazed windows, they were  draughty but they didn't have trickle vents like the new ones have. 

I don't want to have central heating on just to heat rooms I hardly use, the whole point in getting new windows was to give me better thermal efficiency and cut my bills not to have them ncrease 

Newbie_John

Kitchen and bathroom tend to have high humidity. You also mention keeping them cold. With new windows all that steam shows up on windows - it is really expected - as it can't go anywhere else.

Your choice is to either:
- air it in the morning before putting heating on
- wipe it off
- use a window vac to sack the moisture
- get a dehumidifier
- keep rooms warmer

Regarding water inside the window - that needs replacing.

kuepper

Newbie_John said:

Kitchen and bathroom tend to have high humidity. You also mention keeping them cold. With new windows all that steam shows up on windows - it is really expected - as it can't go anywhere else.

Your choice is to either:
- air it in the morning before putting heating on
- wipe it off
- use a window vac to sack the moisture
- get a dehumidifier
- keep rooms warmer

Regarding water inside the window - that needs replacing.

I don't generate much steam, a few kettles a day, few pans a week, washing up a couple of times a week, wash and shave every morning. Plus the trickle vents on the new windows are open. Besides breathing and houseplants there's not much other water vapour created and I've no problem in bedrooms and living room 

Mr.Generous

kuepper said:

Newbie_John said:

Kitchen and bathroom tend to have high humidity. You also mention keeping them cold. With new windows all that steam shows up on windows - it is really expected - as it can't go anywhere else.

Your choice is to either:
- air it in the morning before putting heating on
- wipe it off
- use a window vac to sack the moisture
- get a dehumidifier
- keep rooms warmer

Regarding water inside the window - that needs replacing.

I don't generate much steam, a few kettles a day, few pans a week, washing up a couple of times a week, wash and shave every morning. Plus the trickle vents on the new windows are open. Besides breathing and houseplants there's not much other water vapour created and I've no problem in bedrooms and living room 

No baths or showers?

Chickereeeee

The only things I can add are:
- it sounds like you keep the place pretty cool, and the kitchen+bathroom colder than  the other '
day rooms'. This would mean the air is closer to its dew point.
- it may be that told, draughty windows caused more air circulation than the trickle vents, which are designed not to cause draughts.
- the recent weather - warm, followed by a sharp drop in temperature  - causes more condensation, similar to heat younget in the autumn,

ThisIsWeird

kuepper said:

2 months ago I had new windows fitted in kitchen and bathroom and a new back door with glazing that opens into the kitchen. Now the weather has got colder I've noticed condensation on the new windows and door and even when I wipe it off it soon recurs and I can see it glistening where the rubber seal meets the glass. It's always on the lowest part of the glass.

I've read elsewhere that this is normal though I didn't expect it - I've had trickle vents open all the time and as I live alone I don't generate much steam.

However I'm concerned that after only 2 months there appears to be condensation on the inside of one of the glazed units in my bathroom, photo attached. So does the unit need replacing or the whole window? I wondered if water from the condensation could have weakened the rubber seal but it shouldn't have been able to get in anyway should it as the unit is supposed to be a vacuum  so is it a manufacturing fault?

I suspect Chicker has it covered. "I don't have any curtains in my kitchen or bathroom. Both those rooms are two I never had any condensation problems with my old double-glazed windows, they were draughty, but they didn't have trickle vents like the new ones have.

My house is pretty draughty, too, so I generally have little issue with condensation forming on windows. It does happen during the current cold snap, tho', and I ain't going to 'ventilate' any more than current - brrrr! So, I tackle the worst each morn with a clean damp cloth - it takes seconds. So, I suspect that's all you are experiencing - your new DG windows are 'better', but they will still be the coldest surfaces in any room, and more so towards the bottom where the air temp is lowest, and air flow likely low too. If you don't want to ventilate even more - quite understandable - then it's either raise the ambient temp - extra energy - or simply keep it wiped away.
Your new windows have 'trickle vents', but these will be mounted at the top, and are for allowing a minimum amount of room ventilation, but not the type of draught that will keep your panes dry, especially near the bottoms - your old windows almost certainly achieved that by having a surrounding draught! The window in my son's room has morning cond if he doesn't crack it to 'vent' opening overnight, but I've also noticed in the very corner of the pane, where the two rubber seals don't meet at a perfect mitre, the resulting air seep keeps a thin perfect line of 'dry' in the middle of the cond beads, as if proving that 'ventilation' is key. And it is - he now opens them to 'vent' position overnight, a dives under the covers; he wakes to a dry room.

I don't want to have central heating on just to heat rooms I hardly use, the whole point in getting new windows was to give me better thermal efficiency and cut my bills not to have them increase" Any room you don't actually use, then heating off to 'frost protect', and leave it well ventilated - windows actually cracked open to that setting, and doors closed - these rooms will be cold, but dry.

If the bathroom window has condie forming actually within the glazed unit - ie you cannot wipe it away - then that unit has failed. No obvious cause - usually just bad luck. They will (should), of course, replace it without question.

If your new DG had replaced single-glazing, then I think you'd have noticed a more significant improvement, but all DG, regardless of how old, is actually pretty effective, so you are unlikely to experience anything transformative by upgrading.

As Chickereeeee points out, there's a fair chance your old DG kept cond away by unintentional ventilation! So, whilst your new stuff may appear initially disappointing, it is almost certainly reducing your energy usage a decent amount, even tho' you are still seeing some condie. There's also a fair chance that you are consciously lowering your home temp in order to save energy, and in the hope that the new DG would equalise things out, but it'll only do that to a relatively small degree.

Your home will be easier to heat, but you do still need to heat the living spaces as before if you are to keep that cond away. Or, ventilate it away. Or, just wipe it up. It'll only be on the coldest evenings.

FreeBear

ThisIsWeird said:

kuepper said:

2 months ago I had new windows fitted in kitchen and bathroom and a new back door with glazing that opens into the kitchen. Now the weather has got colder I've noticed condensation on the new windows and door and even when I wipe it off it soon recurs and I can see it glistening where the rubber seal meets the glass. It's always on the lowest part of the glass.

I've read elsewhere that this is normal though I didn't expect it - I've had trickle vents open all the time and as I live alone I don't generate much steam.

However I'm concerned that after only 2 months there appears to be condensation on the inside of one of the glazed units in my bathroom, photo attached. So does the unit need replacing or the whole window? I wondered if water from the condensation could have weakened the rubber seal but it shouldn't have been able to get in anyway should it as the unit is supposed to be a vacuum  so is it a manufacturing fault?

If the bathroom window has condie forming actually within the glazed unit - ie you cannot wipe it away - then that unit has failed. No obvious cause - usually just bad luck. They will (should), of course, replace it without question.

If your new DG had replaced single-glazing, then I think you'd have noticed a more significant improvement, but all DG, regardless of how old, is actually pretty effective, so you are unlikely to experience anything transformative by upgrading.

One thing I did notice after having new double glazed windows fitted was condensation forming on the outside of the glass on some chilly days. This condensation looked very similar to @kuepper and could be mistaken for moisture within the sealed unit. Before calling the installer, give the outside of the window a quick wipe down.

And replacing my knackered old 1970s vintage DG windows instantly improved comfort levels inside. Rooms are now much easier to heat.