Quizzes & Puzzles6 mins ago
Window condensation
8 Answers
We have DG windows, but still get condensation on the bedroom windows in a morning. Why and what can we do about it. Is it just lack of ventilation or what ?
Answers
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Generally, the main reason for condensation is poor insulation and poor internal circulation/
19:02 Thu 16th Sep 2010
Hi Maz ......... DG windows don't give quite as much insulation as people think. It's still the coldest surface in the room for water to condense on.
Modern windows should have trickle vents to let the vapour escape. A little ventilation is the only answer ................... that, or stop breathing lol
Modern windows should have trickle vents to let the vapour escape. A little ventilation is the only answer ................... that, or stop breathing lol
Generally, the main reason for condensation is poor insulation and poor internal circulation/ventilation - this is why condensation is a major problem in the UK and not generally seen as a threat or even occurring much elsewhere even where the outdoors is at times significantly colder than here. The reason is that the UK (a cold country) housing stock is generally extremely poorly insulated if at all, and often extremely draughty. From this stems another problem which is very limited heating, leading to people partitioning their accommodation into small pockets that are (slightly) warmer than the rest of the house, but only for part of the time, and thus sharply increasing the likelihood of condensation forming. Traditionally, the national solution is to furiously vent to the outside (ether by leaving windows wide open to the winter cold, or by constantly allowing a draught - central cooling, if you will) and this is something that at a stroke does away with any warmth there ever is or might be ultimately available to dry things out. This still goes on a lot and it is clear that large numbers of people (notably including those who should know better because they are looked to for advice) completely fail to undertsand the mechanism that brings about condensation.
Kitchens are cells with the doors closed, bathrooms are closed all the time, and the same goes for living rooms and bedrooms. All of these rooms are cold most of the time and only when occupied does the temperature rise - and that is just the air, not the rest (hence the draughty feeling even within a closed room). Britain is close to being unique whereby pieces of domestic furniture are heated to combat the cold (heated food trolleys, electric blankets, etc.), and little wonder: Who would in effect pour their money into the outdoors trying to heat a house that thermally leaks like the proverbial sieve.
Kitchens are cells with the doors closed, bathrooms are closed all the time, and the same goes for living rooms and bedrooms. All of these rooms are cold most of the time and only when occupied does the temperature rise - and that is just the air, not the rest (hence the draughty feeling even within a closed room). Britain is close to being unique whereby pieces of domestic furniture are heated to combat the cold (heated food trolleys, electric blankets, etc.), and little wonder: Who would in effect pour their money into the outdoors trying to heat a house that thermally leaks like the proverbial sieve.
Part 2
But this means that all surfaces in each and every room are pretty much permanently cold. When the air temperature (yes, including in our breath) rises, it starts to dry out the furniture, linen, drapes, carpeting, etc., and even the walls. The upshot is that moisture increases in the air, sometimes close to saturation level, and when that air comes into contact with a colder surface it cannot retain the water and condensation settles on that surface. Thus, the coldest and/or most heat conducting surfaces will show the condensation first: Glazing and mirrors, tiles and unheated metal surfaces, the insides of cupboards such as in the kitchen, wall areas behind furniture, shiny and impervious surfaces and then all wall/ceiling/floor surfaces generally.
Having curtains drawn across a window demonstrates the effect very well - the air is to a substantial degree trapped in a slow moving mass where it has time to cool way below the room temperature and as it does it dumps the moisture it contains onto the glass. For the very same reason, a cold bathroom that is not only kept closed during showering but also firmly shut afterwards will see large amounts of water deposited on every surface within it. Only if the room is warm to start with, afterwards and is within a warm house with freely circulating air within it (generally open doors or at least well ajar) will condensation at most be seen as very slight fogging at the edges of the window glass (nowhere else) and only on a cold day. To keep the house warm at a manageable cost (very modest if foreign standards are adopted) you must have good insulation, good draughtproofing, and aim for temperatures at 18 degrees or above at all times (stop-start heating is the least effective and relatively most expensive). Otherwise you are doomed to a traditionally British life of feeling cold in dank conditions. But at least you can alleviate the worst effects by not deliberately making things worse - a
But this means that all surfaces in each and every room are pretty much permanently cold. When the air temperature (yes, including in our breath) rises, it starts to dry out the furniture, linen, drapes, carpeting, etc., and even the walls. The upshot is that moisture increases in the air, sometimes close to saturation level, and when that air comes into contact with a colder surface it cannot retain the water and condensation settles on that surface. Thus, the coldest and/or most heat conducting surfaces will show the condensation first: Glazing and mirrors, tiles and unheated metal surfaces, the insides of cupboards such as in the kitchen, wall areas behind furniture, shiny and impervious surfaces and then all wall/ceiling/floor surfaces generally.
Having curtains drawn across a window demonstrates the effect very well - the air is to a substantial degree trapped in a slow moving mass where it has time to cool way below the room temperature and as it does it dumps the moisture it contains onto the glass. For the very same reason, a cold bathroom that is not only kept closed during showering but also firmly shut afterwards will see large amounts of water deposited on every surface within it. Only if the room is warm to start with, afterwards and is within a warm house with freely circulating air within it (generally open doors or at least well ajar) will condensation at most be seen as very slight fogging at the edges of the window glass (nowhere else) and only on a cold day. To keep the house warm at a manageable cost (very modest if foreign standards are adopted) you must have good insulation, good draughtproofing, and aim for temperatures at 18 degrees or above at all times (stop-start heating is the least effective and relatively most expensive). Otherwise you are doomed to a traditionally British life of feeling cold in dank conditions. But at least you can alleviate the worst effects by not deliberately making things worse - a
Part 3
But at least you can alleviate the worst effects by not deliberately making things worse - allow air to circulate freely within your dwelling and don't deliberately cool things down by opening windows or directly funnelling the cold outdoors straight into your house. Consider moving away from Victorian values and insulate, draughtproof, etc. - all that after closing off the chimney (totally making sure of at least filling the pipe from top to below the roof line) and ripping out the fire place.
But at least you can alleviate the worst effects by not deliberately making things worse - allow air to circulate freely within your dwelling and don't deliberately cool things down by opening windows or directly funnelling the cold outdoors straight into your house. Consider moving away from Victorian values and insulate, draughtproof, etc. - all that after closing off the chimney (totally making sure of at least filling the pipe from top to below the roof line) and ripping out the fire place.
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