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Condensation on bedroom windows in the morning.

  • 25-11-2020 11:34am
    #1
    Registered Users Posts: 1,494 ✭✭✭


    Hi folks,

    I’m wondering how to solve condensation on my bedroom windows in the morning. My OH keeps some photo frames on the window sill and have just realized this morning that one of them has gotten mouldy.

    Windows are PVC double glazed. Curtains are closed at night, probably trapping cold air there. Room does not have a vent to the outside, but it does have trickle vents on the windows. North facing. Door closed at night. Rented property so can't do any mad DIY stuff. House is pretty well insulated, never gets too cold.

    I have read many threads around and just need a couple of pointers.

    1: Install trickle vents.

    We already have them on all windows in the house, and they’re open.

    2. Use a dehumidifier.

    A big dehumidifier came with the house (bad sign?) How do we get to sleep when it’s on? Or do we run it during the day? For how long? How often?

    3. Open the window when you sleep.

    We live on the ground floor in an urban area so can’t fully open it, but will open it on the “latch” open function and see if it works.

    4. Put that melted plastic cling film stuff from amazon on it.

    Does this work?

    5. Ventilate the house.

    There is a positive input ventilation contraption in the kitchen only. In the farthest corner of the house. Shouldn’t it be in the hallway so it can get to all rooms in the house? It’s pretty useless then, am I right? I’ve also read that the house must be airtight for this to work. We have trickle vents on all windows. I was thinking of turning this OFF as it just constantly blasts cold air into the kitchen. It’s like a butchers walk in freezer in the mornings.

    6. Use an extractor fan when cooking.

    We do.

    7. Use an extractor fan when showering

    The shower does not have one, nor does it have a radiator. We crack the window while showering.

    8. Do not dry clothes on radiators / hangers etc.


    We don’t We use a condensing tumble dryer.

    9. Heat the room that has the condensation problem

    It is heated for 8 hours a day. Not heated at night as the house is fairly well insulated and well, we're asleep.

    What can I try next? Or am I doing anything wrong?


Comments

  • Registered Users Posts: 14,643 ✭✭✭✭loyatemu


    Hi folks,

    I’m wondering how to solve condensation on my bedroom windows in the morning. My OH keeps some photo frames on the window sill and have just realized this morning that one of them has gotten mouldy.

    Windows are PVC double glazed. Curtains are closed at night, probably trapping cold air there. Room does not have a vent to the outside, but it does have trickle vents on the windows. North facing. Door closed at night. Rented property so can't do any mad DIY stuff. House is pretty well insulated, never gets too cold.

    I have read many threads around and just need a couple of pointers.

    1: Install trickle vents.

    We already have them on all windows in the house, and they’re open.

    2. Use a dehumidifier.

    A big dehumidifier came with the house (bad sign?) How do we get to sleep when it’s on? Or do we run it during the day? For how long? How often?

    3. Open the window when you sleep.

    We live on the ground floor in an urban area so can’t fully open it, but will open it on the “latch” open function and see if it works.

    4. Put that melted plastic cling film stuff from amazon on it.

    Does this work?

    5. Ventilate the house.

    There is a positive input ventilation contraption in the kitchen only. In the farthest corner of the house. Shouldn’t it be in the hallway so it can get to all rooms in the house? It’s pretty useless then, am I right? I’ve also read that the house must be airtight for this to work. We have trickle vents on all windows. I was thinking of turning this OFF as it just constantly blasts cold air into the kitchen. It’s like a butchers walk in freezer in the mornings.

    6. Use an extractor fan when cooking.

    We do.

    7. Use an extractor fan when showering

    The shower does not have one, nor does it have a radiator. We crack the window while showering.

    8. Do not dry clothes on radiators / hangers etc.


    We don’t We use a condensing tumble dryer.

    9. Heat the room that has the condensation problem

    It is heated for 8 hours a day. Not heated at night as the house is fairly well insulated and well, we're asleep.

    What can I try next? Or am I doing anything wrong?



  • Registered Users Posts: 6,544 ✭✭✭Mollyb60


    I used a 5L dehumidifier in my last apartment. It was left on 24 hours a day and would take about the full 5L out of the air each day and was quite effective in keeping the condensation in the flat to a minimum. It made a humming noise but to be honest, like most things, you get used to the sound and it never kept me from sleeping.

    If you don't own the place there's little you can do to control the damp, there's just not enough air flow through the house and that's not a simple problem to solve.


  • Moderators, Science, Health & Environment Moderators Posts: 4,665 Mod ✭✭✭✭Tree


    I use a window vac to hoover off the condensation in the mornings. Not gonna prevent it happening but it reduces the mould that used to form on the frame.


  • Registered Users Posts: 6,454 ✭✭✭10-10-20


    Two items: Are you sure that you have an extractor in the kitchen, or is it a recirculating filter? Many newer houses have just the recirculating one and that does not create a path for cooking moisture to escape. Secondly, is the shower alongside the room with the condensation? If so, I'd suggest that this is a major source of moisture. Does it dry out fully between showers? Is there mold there?

    Ideally you need to tackle moisture at it's source, so if the bathroom is large enough and it's electrically safe to do so, I'd recommend that the dehumidifier be fitted there and left to reduce the RH down to ~60% RH on average. Leave the window fully open when showering though, or have the landlord fit a ceiling/wall or window vent. If it's not possible to do the put the dehumidifier outside the door to the bathroom and leave the door open afterwards.

    Also get a humidity meter and use it to understand the relationship between temperature, RH and dew-point. It might help somewhat.
    See some of the info in this thread:
    https://www.boards.ie/vbulletin/showthread.php?t=2058132187


  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    Thanks. I don't think the landlord is going to fit an extractor fan. I've been waiting a month for him to fix some window hinges.
    Are you sure that you have an extractor in the kitchen, or is it a recirculating filter?

    How do I check this?

    Anyway we closed the bathroom door after the shower yesterday, and opened the bathroom window, and ran a dehumidifier in the bedroom for a couple of hours.

    The windows were find this morning.

    The problem is, I don't know which one of them fixed it. The dehumidifier? Or leaving the bathroom window open and closing the door? I also left the bedroom window open on "lock latch" or whatever it's called. The outside temperature wasn't as bad either so perhaps the windows were slightly warmer. Also, we left the curtains open a tiny bit to let air get into the space between the curtain and the window. So I need to do a process of elimination and find out which one of them sorted it. Because I don't want to be doing this rigmarole every night for the rest of my life (in this apartment anyway).

    Just another question on ventilation. Opening all the windows in the house for an hour - is this a good idea? Yes the house will get cold, but am I leaving moisture out or making it worse? Irish weather is pretty soggy at the best of times. Am I leaving soggy air in?


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  • Registered Users Posts: 14,643 ✭✭✭✭loyatemu


    I think generally the air outside is drier (partly because it's colder). It's generally a good move to open a window, probably not necessary to have them all open all day though.


  • Registered Users Posts: 6,038 ✭✭✭The Continental Op


    Just a note on the noise the dehumidfier makes. We have a big air filter thingy in the bedroom as it helps take stuff out of the air that upsets my wifes lungs. It was annoying at first but now its more difficult to go to sleep unless its on making its noise.

    Wake me up when it's all over.



  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    10-10-20 wrote: »
    Two items: Are you sure that you have an extractor in the kitchen, or is it a recirculating filter?

    Ah for FECK sake. Just checked and did a bit of googling and it's a recirculating filter. So I've been blasting moist air all over the kitchen when I thought it was actually being extracted. I'd leave the "extractor" on for a while afterwards thinking I better remove more moisture from the air.

    Whoever designed these houses need to be taken out the back and shot.


  • Registered Users Posts: 23,179 ✭✭✭✭ted1


    loyatemu wrote: »
    I think generally the air outside is drier (partly because it's colder). It's generally a good move to open a window, probably not necessary to have them all open all day though.

    An open fly window makes a huge difference


  • Registered Users Posts: 6,038 ✭✭✭The Continental Op


    Bet you've never replaced the filter in what is a system to remove cooking smells rather than ventilate the house.

    Wake me up when it's all over.



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  • Registered Users Posts: 24,647 ✭✭✭✭punisher5112


    Insulation and ventilation is key.....

    If possible open the windows in the mornings or during the day but if the insulation isn't adequate then that needs to be tackled as does having an actual vent in each room.


  • Registered Users Posts: 5,322 ✭✭✭JustAThought


    It sounds like an awful lot of effort for a bit of drizzle on the inside of a window in the morning. Now that you’ve spotted it can you not just keep
    the photo-frames off the windowledge and do what generations have done and wipe the window and windowsill clear every morning? Sounds like a lot less hassle?

    If the bathroom dosn’t have an extractor fan I’d be assuming it was a small bedroom converted or add on? I can’t imagine a room with no active suction out filling with hot steam twice a day would be great unless you have a through draught from another room to force the steam out the window every time you shower. Brrr. Big waste of heat.

    Next time you’re moving to rent if the house is
    filled with de-humidifiers and air balancing gadgets take the que and rent another place!

    I’d say go with the mildly annoying but lesser hassle of a dedicated facecloth or tea-towel.


  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    Bet you've never replaced the filter

    Well I've just moved in so you are correct.
    It sounds like an awful lot of effort for a bit of drizzle on the inside of a window in the morning.

    I think this house may have had a mould problem in the past. There's a strange odour sometimes that I can't put my finger on. And the place was freshly painted. It may be gone off paint, or they may have painted over mould spots. I'm just being extra paranoid.


  • Registered Users Posts: 6,038 ✭✭✭The Continental Op


    Well I've just moved in so you are correct.

    That could be an "interesting" job if its not been done in a while. You only need to get a cheap genric filter and cut it to size https://www.amazon.co.uk/Universal-Cooker-Carbon-Kitchen-Extractor/dp/B07846GGRR/ but if you are unlucky you may find an accumulation of fat and grease particularly if previous tenants did a lot of frying.

    Wake me up when it's all over.



  • Registered Users Posts: 11,698 ✭✭✭✭Goldengirl


    Well I've just moved in so you are correct.



    I think this house may have had a mould problem in the past. There's a strange odour sometimes that I can't put my finger on. And the place was freshly painted. It may be gone off paint, or they may have painted over mould spots. I'm just being extra paranoid.

    You are right to be concerned .
    A damp home can play havoc with your health .
    If this place isn't yours to modify ie new vents or better moisture extraction , you could use the humidifiers and open windows, early inthe day so you can avoid heat loss .
    Also mention it to the landlord and get him to invest in humidity contolled vents ( Aeroco do them ) and / or better extractors for kitchen and bathroom . Its in the landlords interests to keep the fabric of the building dry , I would have thought.


  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    Goldengirl wrote: »
    You are right to be concerned .
    A damp home can play havoc with your health .
    If this place isn't yours to modify ie new vents or better moisture extraction , you could use the humidifiers and open windows, early inthe day so you can avoid heat loss .
    Also mention it to the landlord and get him to invest in humidity contolled vents ( Aeroco do them ) and / or better extractors for kitchen and bathroom . Its in the landlords interests to keep the fabric of the building dry , I would have thought.

    I've seen lots of advice to open the windows. I was going to do it the other day and literally blast the house with fresh air opening all the windows for an hour, but checked the weather and it was 97% humidity outside! So just cracked them the tiniest bit.

    How is it a good idea to let soggy air into the home?


  • Registered Users Posts: 14,643 ✭✭✭✭loyatemu


    I've seen lots of advice to open the windows. I was going to do it the other day and literally blast the house with fresh air opening all the windows for an hour, but checked the weather and it was 97% humidity outside! So just cracked them the tiniest bit.

    How is it a good idea to let soggy air into the home?

    what temperature was it outside though? cold air holds less water than warm air.

    air at 10C that's at 95% RH, will only be at about 50% RH when warmed up to 20C

    RH is relative - 100% is the point at which water starts condensing out of the air, that's why it condenses on a cold window pane, but not a warm internal wall. It's the same air with the same amount of water in it, just the temperature is different.


  • Registered Users Posts: 11,698 ✭✭✭✭Goldengirl


    I've seen lots of advice to open the windows. I was going to do it the other day and literally blast the house with fresh air opening all the windows for an hour, but checked the weather and it was 97% humidity outside! So just cracked them the tiniest bit.

    How is it a good idea to let soggy air into the home?

    That air is colder as above poster said and won't hold as much moisture .
    Look at my post , that was the minimum that I suggested could be done and early in the day so you can then warm the house afterwards.
    It was the only option most people have had to air their homes out in the past and while not ideal is better than wet and mould building up in your home .

    Ideally condensation is prevented by good windows , removal of moisture laden air by ventilation or extraction ,and good insulation.
    You know that if the PIV isn't working it might be where the unit is positioned , whether it has access to all areas ie doors closed , or too much moisture being produced , when dehumidifiers and extractors need to be used .
    I think that you should contact the landlord and ask him to check the PIV unit and maybe install some stronger extractors , and / or new vents ..


  • Registered Users Posts: 797 ✭✭✭3d4life


    ...



    This came up as a suggestion while I was looking at another YT.


  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    Just a quick update. I posted this thread over a week ago.

    I have not had condensation on the bedroom window for a few days now. Well, just a tiny bit at the bottom but barely noticeable. Looks like somebody breathed on it. And it was 2 degrees outside last night. Last week it was if somebody emptied a spray bottle on it.

    My bathroom doesn't have a radiator, nor an extractor fan. Whoever designed this place should be put up against a wall and shot.

    So I used to leave the bathroom door open after a shower, crack the window about a centimetre open (because it was frozen outside). The idea was to leave the heat in and roast the moisture away. I guess it was just roasting the moisture into the air, probably not going anywhere.

    Anyway, we started closing the bathroom door after a shower, and leaving the window fully open for about 15 mins. This probably fixed it. The bedroom is next door to the bathroom.

    I also blasted the dehumidifier one day for about 6 hours. Probably extracted about a litre of water. Haven't used it in a week. So I'm guessing it's the shower door that sorted it.

    This solution is very annoying though. Because my missus would have a shower, leave the window open afterwards (2 degrees outside) then it's my turn for a shower but the bathroom is now 2 degrees centigrade. Horrific. Might as well just use a bucket of warm water out in the bush, at least there'll be some nice scenery while I'm scrubbing me bits.


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  • Registered Users Posts: 33,649 ✭✭✭✭Hotblack Desiato
    Restaurant at the End of the Universe


    Funny how you never mentioned in this thread that you like to keep the windows open at night in the middle of winter :rolleyes:

    It took a while but I don't mind. How does my body look in this light?



  • Registered Users Posts: 1,494 ✭✭✭JackieChang


    Funny how you never mentioned in this thread that you like to keep the windows open at night in the middle of winter :rolleyes:

    I'm not able to keep the window open at night in the middle of winter because I'm on the ground floor in an urban area.

    What's your point?


  • Registered Users Posts: 8,560 ✭✭✭CoBo55


    Just a quick update. I posted this thread over a week ago.

    I have not had condensation on the bedroom window for a few days now. Well, just a tiny bit at the bottom but barely noticeable. Looks like somebody breathed on it. And it was 2 degrees outside last night. Last week it was if somebody emptied a spray bottle on it.

    My bathroom doesn't have a radiator, nor an extractor fan. Whoever designed this place should be put up against a wall and shot.

    So I used to leave the bathroom door open after a shower, crack the window about a centimetre open (because it was frozen outside). The idea was to leave the heat in and roast the moisture away. I guess it was just roasting the moisture into the air, probably not going anywhere.

    Anyway, we started closing the bathroom door after a shower, and leaving the window fully open for about 15 mins. This probably fixed it. The bedroom is next door to the bathroom.

    I also blasted the dehumidifier one day for about 6 hours. Probably extracted about a litre of water. Haven't used it in a week. So I'm guessing it's the shower door that sorted it.

    This solution is very annoying though. Because my missus would have a shower, leave the window open afterwards (2 degrees outside) then it's my turn for a shower but the bathroom is now 2 degrees centigrade. Horrific. Might as well just use a bucket of warm water out in the bush, at least there'll be some nice scenery while I'm scrubbing me bits.

    Don't open the window until you're both washed or go playboy and shower together:D save electricity too, keep the Eco's happy.


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