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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Building Questions >> Condensation! https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1134489648 Message started by deefadog on Dec 13^th, 2005, 4:00pm

Title: Condensation!
Post by deefadog on Dec 13^th, 2005, 4:00pm

Hope this is the best place to post this -

I have a bungalow, with PVC windows, good attic insulation and cavity wall insulation!

When we get cold weather, what ever room that is slept in we get condensation on the windows!

I have tried those absorption trays. but they don't really work that well!

Is there anything i can do to stop this or is it just a fact of life?

Thanks

Title: Re: Condensation!
Post by sparxxxx on Dec 13^th, 2005, 5:08pm

Had exactly the same problem its condensation from the kitchen and the bathroom. You need to install extract fans in both rooms.
It's the only way

Title: Re: Condensation!
Post by CWatters on Dec 13^th, 2005, 5:37pm

If you seal up your house to reduce draughts the water vapor produced by breathing, cooking, washing, showering etc can't get out so it builds up. The air can only hold a certain amount of water before it condenses out somewhere - typically on the coldest surfaces like windows. You can try and eliminate all cold surfaces but that just delays the problem or moves it somewhere else.

You could use a dehumidirier that extracts the water from the air but they typically need regular emptying by hand and have running coats.

The real answer is to provide ventilation that allows the wet air out and dry air in. Ventilation is frequently provided by trickle vents in the frames of windows. Check yours aren't blocked or closed. If they aren't sufficient try adding bathroom and kitchen extractor fans and use them. Ideally hook them up to the lights so they are on when the room is in use. They blow damp air outside and fresh air enters through your trickle vents or other openings. This is somewhat inefficient in the winter because you have paid to heat the air that you are blowing outside.

In my view the only "perfect" solution is to install a "Heat recovery Ventilation systems". They work by extracting damp air from the kitchen and bathroom using ducts in the roof space. The damp air goes through a heat exchanger which extracts/recovers the heat and uses it to warm up the incoming fresh air. The warmed freshair is then fed into dry rooms like the bedrooms and living room by another set of ducts.

It's possible to DIY install these systems and you can see several suppliers at most of the selfbuild shows.

http://www.villavent.co.uk/heat-recovery-ventilators.htm

http://www.rega-uk.com/

http://www.feta.co.uk/rva/

Title: Re: Condensation!
Post by deefadog on Dec 13^th, 2005, 8:28pm

Thanks for the replies!

Our windows do not have vents :( and also the rooms affected are the bedrooms, the kitchen and bathroom are fine!

Fitting an extractor fan in the bedrooms will be too noisey and our young daugter will not appreciate that :)

I think the only thing to do is to get a dehumidirier, these can do the whole house can't they? so it can be running in a room away from th bedrooms, and as long as the doors are ajar they should work? not sure how noisey they are?

Last year i got a small fan connected to a timer plug and on the back of the fan i put some tumble drier piping and put the other end on the radiator so it would come on around 5AM and blow hot air at the windows!

It did work, but i guess it's just masking the problem, fresh wet air should have some release!

Looking into the Heat recovery Ventilation systems! maybe not for bungalow, as we plan to move, but as we are hoping on purchasing a property we can do up, these would be ideal, and easily forgot untill all the wok has been completed!

Great inks, thanks - etched in memory for the futre :)

Title: Re: Condensation!
Post by woodsmith on Dec 13^th, 2005, 9:25pm

A cheaper solution might be to open the window at night?

Maybe fit a lockable stay or a restrictor like this http://www.screwfix.com/app/sfd/cat/pro.jsp?cId=100635&ts=08975&id=23507

if you are concerned over security.

Title: Re: Condensation!
Post by big_all on Dec 13^th, 2005, 10:29pm

to add to woodsmiths comments
ventilation[open window essential]

if you have heavy [lined]curtains you will reduce the condensation on the window and keep the room a bit warmer and possibly avoid open window at night then you might get away with 30mins or so ventilation in the morning and evening [with the curtains open]

Title: Re: Condensation!
Post by billythekid on Dec 14^th, 2005, 1:02am

this adds nothing of help, lol, but I think i read somewhere you breathe out a litre of moisture(water?) a night while sleeping.

dehumidifier is my suggestion, or towel on the sill.

btk

Title: Re: Condensation!
Post by deefadog on Dec 14^th, 2005, 10:50am

woodsmith - thanks for the link, may fit these anyway - handy in the summer!

Living in a bungalow does have secuity issues!

Going to probablly get a dehumidifier, anyone know any good makes?

Just found this - http://www.4air.co.uk/product_info.php/products_id/996067879/pname/EF880S-Mini-Dehumidifier-Silver-Peltier-Technology

May get 3 of these for each bedroom! Waht do you think - will it do the job?

or this one - http://www.4air.co.uk/product_info.php/products_id/996067890/pname/QT120-12-l---day-Dehumidifier%2C-3.3-l-tank%2C-up-to-140-sq-meters

this will do the house, but i guess you would have to leave the doors internal doors open for this to be affective?

Title: Re: Condensation!
Post by CWatters on Dec 14^th, 2005, 11:12pm

That last one says..

Moisture removal at 30C, 70% R.H. L/day: 8.5 l
Removes up to 12 litres/day (QT120)
3.3 litre water tank

So you could have to empty it between two and four times a day?

Title: Re: Condensation!
Post by JerryD on Dec 15^th, 2005, 12:15am

I have a dehumidifier in my games room which is 20' x 30'. When I built the room there was a problem with condensation so I drilled a 20mm hole in the wall and connected a short length of hosepipe directly from the dehumidifer to outside.

It was left on permanently for several weeks but now is is never needed.

The hose idea meant I never needed to empty it.

These dehumidifeirs are a bit noisy though (sound like a fridge compressor but twice as loud) so might need to be away from bedrooms.

Title: Re: Condensation!
Post by deefadog on Dec 15^th, 2005, 9:32am

The noise is a concern especially at night!

I would only really have this on during this time anyway, as it's fine in the day!

There a few on ebay also, EBAC make, any good?

Title: Re: Condensation!
Post by JerryD on Dec 15^th, 2005, 11:40pm

Mine's a Matsui 135, very good (if still available?)

Title: Re: Condensation!
Post by supersparky on Dec 15^th, 2005, 11:43pm

id say a humidity operated extractor fan is best

ss

Title: Re: Condensation!
Post by deefadog on Dec 19^th, 2005, 9:39am

Jerry i could not find your one, but i got this in the end -

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=6022637509&rd=1&sspagename=STRK%3AMEDW%3AIT&rd=1

Supersparky - I agree - biut to much hassle for now, but i may do this in the future!

I'll post back when i recieve the humidifier and test it out!

Merry Xmas all

Title: Re: Condensation!
Post by deefadog on Dec 20^th, 2005, 7:03pm

Ok, the dehumidifier arrived today :) got it set up, but the instructions are very vague!

It has a humidistat! does this mean that when i set the conditions, it will only come on when the moisture raises above that level? and stop when it'd done it's job?

As it did work for about 10 minutes, now it has shut off on the setting i have it at, if i knock it up a knotch it will run again!

Thanks in advance, merry xmas!

Title: Re: Condensation!
Post by CWatters on Dec 20^th, 2005, 7:26pm

Quote:

It has a humidistat! does this mean that when i set the conditions, it will only come on when the moisture raises above that level? and stop when it'd done it's job?

Yes you got it... except the knob works backwards. You turn the dial UP (clockwise) to turn the humidity setting DOWN.

This looks like a generic manual on their web site..
http://www.ebac.com/dehumidifiers/literature/files/ddinstructiontext2003.pdf

Quote:

Humidistat: The humidistat is an adjustable sensor which detects changes in the moisture
content of the air in your home. The correct setting will depend on a number of factors including
the weather and your lifestyle. Initially, turn the humidistat fully clockwise (to its highest setting).
The unit will begin to operate and you will feel a flow of air through the front grille.
Leave the unit at this setting until signs of excess moisture (such as condensation on windows)
are reduced, This usually takes between 2 and 4 weeks although in extreme conditions it may
take up to eight weeks. When this is achieved, reduce the humidistat setting by turning the knob
slowly anti-clockwise until the unit switches off, but no further. The unit will now switch on and off
automatically.

Title: Re: Condensation!
Post by deefadog on Dec 21^st, 2005, 10:45am

Thanks, get i now!

Just got to trial and error now, untill i find the right setting :)

Thanks all for all the help and advice, most appreciated!

Happy Xmas and have a cyber pint on me :)