Whats with condensation?

fatchance

Hi all,

what the hell is it with condensation? I have a new house, well insulated and with double glazed uPVC windows, and there is still a lot of water on them in the mornings!!

I remember as a kid there'd be near puddles on the window boards when we got up for school, people used to say it was the windows?

Any reason for this other than warm air meeting a cold surface????? It's all windows too, but bedrooms worse as you'd expect. And each room vented.

Is yours the same?

Confused

cnocbui

Yes, the same.

Ireland has very high humidity for most of the year. The cold windows are just acting like dehumidifiers. Speaking of which, a dehumidifier might help in reducing the problem.

Mine pulls about 5 litres of water from the air in a day, so there is a lot of moisture there to condense onto windows - unless the dehumidifier gets it first of course.

fatchance

5 Litres a day!! Thats a fair amount. Is that humidifier you have a small thing and is it noisy?

If it wasn't too expensive (things tight atm) I might consider geting one.

cnocbui

Mine is about the size of two microwave ovens and It does make some noise, but it is a sort of background thing.

They of course vary in quality and capacity and so prices vary, but they can be had from about €115 upwards. There are some here but argos have them as well and no doubt elsewhere as well: http://www.powercity.ie/?par=40-55

Currys seem to have them too, at good prices:http://www.currys.co.uk/martprd/store/cur_page.jsp?BV_SessionID=@@@@0064000011.1259534252@@@@&BV_EngineID=ccciadeimfmdledcflgceggdhhmdfhm.0&page=Product&fm=null&sm=null&tm=null&sku=359384&category_oid=

bazzjazz

I was just going to post up the same query. 2 upstairs bedroom windows to the front of the house suffer very badly from condensation. We also get a build up of mould around the window frame and adjoining wall.

Do you get the same? Would love to know how to treat the mould.

K_user

This is really odd! I was just going to ask that question as I have to same problem.

I just cleaned down 2 windows and the floor around my exterior French Doors.
All of which are in my Kitchen/Dinning room.

The house is brand new, we are just a year in it, self build, there wasn’t a problem up until last week, its warm, well heated and double glazed.

The only thing I can think of is that the windows directly face the sunrise. Might that effect the condensation and cause mould growth?

youtheman

It's basic physics. Air has the ability to absorb a certain amount of water (into vapour). Once it hits the limit it is saturated, and can't take any more.

The very act of living in a room means we are putting extra moisture into the air. During the summer the air starts off dry, so can absorb a lot more. During the winter it is already fairly saturated, so can take a lot more.

When the warm air hits a cold surface then some of the water is transferred from the vapour phase into the water phase (i.e condensation).

So to help the problem you have a few options:

1. keep the air warm, and avoid the condensation you get when the warm air hits a cold surface.

2. get rid of the saturated air and replace with fresh air (i.e. ventilation or extraction)

3. dry the air (i.e. de-humidification).

4. reduce the amount of water being transferred into vapour. Don't dry clothes on radiators. Limit the numbers of persons in the room (I know, not practical). Don't leave the door from the en-suite open following a shower.

So in an ideal world you would have a good thermal bridge in your windows (the inside of the window would be at, or near, the same temp as the room temp). So you have no condensation. Then when you get up in the morning you open the windows and replace the saturated air with clean fresh air.

Alun

For reference, does anyone know what's a 'normal' humidity percentage at average room temperatures?

barney150

regarding the mould, detol do a spray 'Mould & Mildew' remover. In a green bottle, available in most supermarkets. Excellent stuff and only costs about €3. spray once and mould is gone in a couple of minutes

youtheman

Copied from the web:

The human body is comfortable when relative humidity ranges between 20 and 60 percent. In your home, an average relative humidity of 35 to 40 percent is appropriate when the outside temperature is 20°F or above. However, during cold weather, higher humidity ranges may cause structural damage because of condensation on windows and on the inside of exterior walls. As outdoor temperatures fall, condensation problems inside may develop.

JohnDigital

Condensation can also be a sign of Carbon monoxide in the home, so its worth checking the appliances in the home too!

http://www.bordgais.ie/corporate/index.jsp?1nID=93&2nID=96&3nID=611&nID=612

shellyb73

Hi,

Quick tip for you is place a cup of salt in the window this helps with condensation, tried and tested..;)

cnocbui

My dehumidifier has a hygrometer built in and displays the current humidity level so I think I have a fair idea of the humidity levels in a new build house with wall vents in all rooms. The humidity is never below 50%, 55-60 some of the time and over 60% for most of the time, topping 70% on not a few occasions.

I tend to turn it on whenever it is 60% or above.

Chlorine/bleach kills and eradicates mold and is cheaper than proprietary products.

Salt is very hygroscopic so will act like a little dehumidifier.

Happynappy

fatchance wrote: »

5 Litres a day!! Thats a fair amount. Is that humidifier you have a small thing and is it noisy?

If it wasn't too expensive (things tight atm) I might consider geting one.

I'm looking to buy one and have been doing a bit of research on what features to look for, which might be of help to you if you're doing your
own research.

- Dehumidifiers with built-in hygrometers measure relative humidity and display the number
- An adjustable humidistat allows you to dial a desired humidity level and the unit will automatically maintain it
- Unless you live in a climate that is warm year-round, consider a unit with an automatic defrost feature
- Dehumidifiers with two-speed fans run quietly at lower humidity levels. They also save on energy costs.
- An overflow protection valve will cause the unit to switch off when the tub is full and needs to be emptied.
- Dehumidifiers that carry the Energy Star label will save money on utility bills.
- Some models have filters that protect the coils from dirt and dust. Make sure you can easily remove the filters and wash them, a task you should do about twice a month. This will allow you to replace the filters less often.
- Built in timer feature

and based on these recommendations , the one I'm looking at at a decent price is
http://www.argos.co.uk/static/Product/partNumber/4250203/Trail/searchtext>DEHUMIDIFIER.htm

Would anyone recommend this or not? It dosen't appear to have a timer feature , how big of a disadvantage is this?

Its € 199 here or else £139 up north.


Another question, I have 2 rooms that I would use this on - the box room and front bedroom. If I were to run it on the landing with both doors open would it be any way effective for both rooms or would I need to move it between each room alternatively?

Murdec

@OP , do you have open vents in the rooms you mention? Lack of airflow is a big contributory factor in condensation.
Personally i would not like to be living along side a dehumidifier , i cant imagine it would be good for your health

cnocbui

Happynappy wrote: »

and based on these recommendations , the one I'm looking at at a decent price is
http://www.argos.co.uk/static/Product/partNumber/4250203/Trail/searchtext>DEHUMIDIFIER.htm

Would anyone recommend this or not? It dosen't appear to have a timer feature , how big of a disadvantage is this?

Its € 199 here or else £139 up north.


Another question, I have 2 rooms that I would use this on - the box room and front bedroom. If I were to run it on the landing with both doors open would it be any way effective for both rooms or would I need to move it between each room alternatively?

Seems to be fine but something with a larger tank would be less hassle. If the rooms are a bit damp at the moment, the most effective use would be to initiailly shut it in each room and let it suck out the bulk of the dampness then use it on the landing, it should be effective because it will reduce the vapor pressure in the air near it which should cause the damper air to difuse out.

I have a big mitsubishi unit that just sits in a central location and I let the difference in vapor pressure even things out.

Murdec wrote: »

@OP , do you have open vents in the rooms you mention? Lack of airflow is a big contributory factor in condensation.
Personally i would not like to be living along side a dehumidifier , i cant imagine it would be good for your health

What negative health effects do you think there might be from filtering dust from the air and discouraging the formation of mold spores and the breeding of dust mites?

I love the ventilation argument. The main reason outside air in this climate might have a lower humidity level than indoors is because it is way colder than the air in a house. Hot air can hold a lot more moisture than cold air. So if you have good enough ventilation you are going to have to heat the incoming air, which is very costly. I would suggest running a dehumidifier would be a lot cheaper.

The only decent form of ventilation in a cold climate is a whole house heat recovery ventilation system where cold incoming air is heated by warm outgoing air, thus preventing the loss of large sums of money you spent heating the warm air.

Unfortunately, such ideal solutions are not cheap.

K_user

I don't know about the OP, but the two windows in my house are on Adjoining walls and there is a vent in between them.

Murdec

cnocbui wrote: »

What negative health effects do you think there might be from filtering dust from the air and discouraging the formation of mold spores and the breeding of dust mites?

To be honest it's not an educated statement , i do know from working in areas with large industrial dehumidifers [construction projects on a time scale] that you feel de hydrated after a few hours!

Happynappy

Murdec wrote: »

To be honest it's not an educated statement , i do know from working in areas with large industrial dehumidifers [construction projects on a time scale] that you feel de hydrated after a few hours!

I think this is where the humidstate plays and important role, in maintaining the RH at a suitable level, around 30 to 50% rather than totally drying out the air.

cnocbui

Murdec wrote: »

To be honest it's not an educated statement , i do know from working in areas with large industrial dehumidifers [construction projects on a time scale] that you feel de hydrated after a few hours!

I'm from Australia where the relative humidity is usually pretty low. My experience is that the low humidity is not necessarily unhealthy so long as you have drink or three.

Rujib1

Leave the window open just a little. Air circulation is the key to a healthy room atmosphere.
The whole country is driven totally bonkers with an insane drive to seal everything up, double glazing blah, blah.
We do not need half the bloody heat. We do not need to live and sleep in rotten air because we have sealed the inside from the outside and cranked up the heat.
Remember when you could literally walk out under the fornt door without opening it, because there was such a gap between floor and bottom of door.
Didn't have the constant sore throats, sniffeling, reach for the lemsip kids than that we have today.
Duncan Stewart is driving ye all mad :rolleyes:

R

Naux

Rujib1 wrote: »

Leave the window open just a little. Air circulation is the key to a healthy room atmosphere.
The whole country is driven totally bonkers with an insane drive to seal everything up, double glazing blah, blah.
We do not need half the bloody heat. We do not need to live and sleep in rotten air because we have sealed the inside from the outside and cranked up the heat.
Remember when you could literally walk out under the fornt door without opening it, because there was such a gap between floor and bottom of door.
Didn't have the constant sore throats, sniffeling, reach for the lemsip kids than that we have today.
Duncan Stewart is driving ye all mad :rolleyes:

R

Well said :D.

WHU

I think I read recently:
Condensation on dbl glazed windows is down to bad fitting, ie not insulated correctly around the frame. The outer pane of glass is ment to keep the chill away from the inner pane keeping it at room temperature. If not insulated correctly the inner pane cools and warm air condensates on the cool glass.

Has anyone else heard of this?
It does fall into line with someone I was speaking to recently who had terrible condensation and black mould spots appearing on paintwork but have just had their cavity walls insulated (injected) including around windows etc and the problem has stopped.
Hopefully this is the cure, I will definately be looking to get this done, (when I can afford it :rolleyes:)

Happynappy

WHU wrote: »

I think I read recently:
Condensation on dbl glazed windows is down to bad fitting, ie not insulated correctly around the frame. The outer pane of glass is ment to keep the chill away from the inner pane keeping it at room temperature. If not insulated correctly the inner pane cools and warm air condensates on the cool glass.

It makes sense and if the seal is failed between panes and the vacuum between is missing, you would expect fogging between the panes, where you can't wipe it off because its on the inside. This would be a good indicator that this has happened.

gsxr1

I live in ireland.

I have no condensation.

I do have open vents. and a warm house.

. ventilation and insulation. Key

leftofcentre

I live in your classic old terraced irish house. When we first moved in the dampness was crazy. I tried the usual keep the windows open trick but no joy. Argos had a dehumidifier for half price so i got one to try it. It is one of the best things i have bought, the first few weeks it took out gallons of water. Now it takes out at least 2-3 pints a day.

Note there is no leaks or anything in the house, the main problem seems to be that we have single brick walls with no cavity (the house is 100 year old). When its cold outside water condenses on the walls.

I would 100% recommend a dehumidifier, argos give you the one month return so you have nothing to lose.

Note I also believe in the benifits of fresh air, and i do open our windows daily for a while, but as our climate is so damp you really do need a dehumidifier to get rid of the water.

A tend to move the dehumidifier around the house, but a friend said you can keep it in one spot as humidity will even out all over the house, anyone know if this is true?

RKQ

K_user wrote: »

The house is brand new, we are just a year in it, self build, there wasn’t a problem up until last week, its warm, well heated and double glazed.

No offense but we are experiencing unusually cold weather at the moment. So prolonged periods of sub zero temperatures will show condensation. It is simply warm air meeting extremely cold surface - 16mm of air cavity or argon gas in window isn't making a huge difference.

Condensation in the cavity between the glass is usually a problem with the window.

Lack of ventilation can increase condensation. A dehumidifier will ease the symtoms but make sure you resolve the cause - check wall vents are clear & open, use mechanical vent in bathrooms, kitchen etc