Green Building Forum - Condensation on the inner face of Double Glazing windows

Condensation on the inner face of Double Glazing windows

mugendo — Thu, 16 Oct 2008 13:46:29 +0100

I live in a standard brick construction house circa 1995.The house is well insulated with oil heating and double glazed windows.
During the cold winter months, heavy considation builds up on the inner face of all windows on the ground & first floor.
I have tried to resolve the problem by keping the heat on for along as possible, 10 hour periods evenings and 2 hours in the morning.
I would welcome comments.

Condensation on the inner face of Double Glazing windows

skywalker — Thu, 16 Oct 2008 13:56:47 +0100

Even the best double glazing will get condensation on it if there is is enough moisture in the air.

How well ventilated is your house - could be the trickle vents on your windows are not enough. Try an experiment, open a window just a crack in each room & see if the condensation gets better.

If this works you may need to look at ventilation - Mechanical Heat Recovery Ventilation is very good at curing condensation problems in houses which are fairly airtight and insulated - have a search here for numerous discussions.

Or your double glazing could be rubbish - are the galzing units clear or cloudy on the inside.

S.

Condensation on the inner face of Double Glazing windows

mugendo — Thu, 16 Oct 2008 14:18:46 +0100

Thanks, I will try your suggestion of the open window.
The glazing units are clear on the inside

Condensation on the inner face of Double Glazing windows

Paul in Montreal — Thu, 16 Oct 2008 14:22:41 +0100

You also should look for sources of excess moisture in your house. Do you, for example, dry your washing on your radiators? Do you mercilessly boil vegetables with no lid on the pan? Opening the window should not be considered a long term solution as you'll just be wasting energy. As skywalker said, a heat recovery ventilation system is a good solution. Or even a dehumidifier might be useful too.

Paul in Montreal.

Condensation on the inner face of Double Glazing windows

sipman — Thu, 16 Oct 2008 15:43:52 +0100

MVHR will solve the problem

we have a client who drys his washing in his loft space using MVHR (has thrown out his tumble dryer) no condensation anywhere in the house

Sipman

Condensation on the inner face of Double Glazing windows

Davipon — Thu, 16 Oct 2008 22:11:29 +0100

Have just finished a major refurb on a bungalow that had serious condensation,turned out to be failed Central heating pipework under screed,warning signs were constant drip in F & E tank,condensation & slight damp at base of some internal blockwork walls.Hope its just lack of vents.

Condensation on the inner face of Double Glazing windows

CWatters — Fri, 17 Oct 2008 11:27:15 +0100

Most likely insuffient ventilation as others have suggested. Life - breathing, cooking, showering - puts water into the air and without ventilation (deliberate or otherwise) the humidity climbs until it rains or condenses out no matter what the temperature. Raising the temperature does increase the amount of water the air can hold, and sometimes this is enough to compensate for a lack of ventilation, but there are limits.

The dilema is that leaving windows open a crack increases heating bills. That's the problem that heat recovery systems are intended to solve. They provide ventilation with reduced heat losses. We'd had problems in all three of the houses we'd owned. When we decided to self build we fitted a whole house vent system with heat recovery. Quite expensive to install but it does work very well. Perhaps too early for you to look at that though.

Condensation on the inner face of Double Glazing windows

tony — Fri, 17 Oct 2008 12:54:38 +0100

Having condensation on the inside of your windows is a good indication that the house is not full of drafts.

Most people dont get this problem because their homes are so air leaky.

Condensation on the inner face of Double Glazing windows

skywalker — Fri, 17 Oct 2008 16:22:38 +0100

I wish that was true in my Kitchen Tony!

S.

Condensation on the inner face of Double Glazing windows

skywalker — Fri, 17 Oct 2008 20:29:18 +0100

mugendo

hows that experiment going?

I'm interested as we are looking hard at MHRV/MVHR whatever the abbreviation is - a cookerXbox in our case (doesn't do bluray apparently - a bit tersely put by the salesman I felt but anyway...).

Although our circumstances are a bit different; leaky 1930's halfway through the destruction cycle.

Regards.

S.

Condensation on the inner face of Double Glazing windows

mugendo — Fri, 17 Oct 2008 23:28:24 +0100

Thanks for all the feedback, i tried the suggestion of opening the trickle vent at the top of the wooden double glazed units.
It worked no condenstation visible!I will try the experiment over a longer term basis.
Thanks again everyone
Mugendo

Condensation on the inner face of Double Glazing windows

midknight — Sat, 22 Nov 2008 15:35:52 +0000

Posted By: DaviponHave just finished a major refurb on a bungalow that had serious condensation,turned out to be failed Central heating pipework under screed,warning signs were constant drip in F & E tank,condensation & slight damp at base of some internal blockwork walls.Hope its just lack of vents.

Well found - nothing like a challenge

Condensation on the inner face of Double Glazing windows

EdF — Sun, 23 Nov 2008 10:14:22 +0000

We spent 4 nights in an excellent new barn conversion near Penrith last week (a holiday rental for a BIG birthday with classic car hire). It was completed last July and had conventional wet CH with radiators. I noticed that there was virtually no condensation on the bedroom windows in the morning, unlike our house, which was built in 1988 and the bedroom windows (DG) are running wet in the morning. The rental CH went off at 11pm and on at 7am, but after getting up in the middle of the night and going back into the bedroom, it was still warm. My only conclusion was that the latest insulation requirements make a LOT of difference.