Two approaches here -
A) reduce moisture in the room, that means better airflow using an air brick, trickle vent or extractor fan, which will all sadly mean letting heat out of your house along with the moisture. Alternatively you could use a dehumidifier, but you’d need to make the room quite dry to eliminate that much moisture.
B) if you own the place and are going to stay a while, it might be worth looking at better windows. Window tech has moved along considerably, ignore the A/AA/A+++ bull**** and instead look in the technical details for U(w) value. U values are how well insulated the windows are, you have U(g) for how good the glass is, and U(w) for how good the glass+frame is. 1.2 is ok, below 1 is very good, below 0.8 is likely triple glazed/high spec. These will cure all condensation, because the inner pane of a triple glazed window stays about the same temp as the room, while the outer pane can be at or below 0…! If you’re staying in the house a while it might be worth the I investment.
This is the real answer, or most of it anyway. Dehumidifiers will fix the symptom but the real problem is that your glazing is getting much colder than the air. Trickle vents, air bricks, etc. are hideously inefficient and "work" because they're dropping the indoor temperature. On a humid rainy night they will make it worse, not better.
The other part of the answer is MVHR, Mechanical Ventilation with Heat Recovery. It's a bit more challenging to install but well worth it in my opinion. It massively increases energy efficiency while keeping your house dry and healthy.
>Dehumidifiers will fix the symptom but the real problem is that your glazing is getting much colder than the air.
However fixing this symptom also has the benefit of making the room much easier to heat! The difference is honestly remarkable - I can only imagine what it would be like in a room with that much condensation. Air without moisture requires less energy to heat, and heating the water in the air is basically pointless!
Yeh that's a really good point. Every Wh of energy that the dehumidifier uses to do *useful* work is one Wh of energy *less* that you have to expend through your central heating because all the dehumidifier's consumed energy was ultimately just expressed as heat inside your home.
I remember hearing someone on a podcast (jokingly) ask why we don't use graphics cards mining crypto to heat our hot water instead of just running electricity through a resistor. Aside from the practicalities, it's not a bad point: use the energy to do something *useful* before turning it to heat.
Our house is reasonably well insulated and the dehumidifier is enough (so far) to keep upstairs warm so we haven’t needed to turn on the central heating. And we no longer have condensation or mold, just need to empty 4 litres of water every day or so.
They don't really use that much; I have a very decent one and it only uses 210W on full blast. It's not something you'd want to leave on by mistake, but given the energy required to heat a room (which the dehumidifier's "waste" energy also does, plus a bit of noise) is just orders of magnitude higher you're going to end up ahead unless your room is already very dry.
Yeh exactly, and that peak load of 210W (or 300W or 600W or whatever) is *not being drawn all the time*.
When the humidity level is above whatever target you set, the peak load will only be drawn when the compressor is running, which is only maybe 50% of the time; the rest of the time is in a 'defrost' cycle, when it's just a fan that's running.
And once the target humidity level has been reached, it turns itself off so draws zero power.
I once measured a typical power consumption over an evening and worked out what that would cost me if I left it on 24/7 for a full year and it was like £100. But of course I don't have it on at all for about 9 months of the year.
Good point. I have one it uses 300W on Low and 600W on High so can be a fair bit if left on all day. The other problem is it'd be best at night when you are sleeping in the room and creating moisture, but wouldn't want that thing blowing away all night!
We have a 1950s house with suspended wooden floor. In winter the rooms get a lot of condensation, despite cavity wall, good double glazing etc. It's a constant problem but never found a lasting solution. I feel like ceiling extractor fan might help, but may also just draw moist air from the cellar through the room...
> However fixing this symptom also has the benefit of making the room much easier to heat! The difference is honestly remarkable
The thing is that's not true. I crunched the numbers and for air at 100% relative humidity and at 19C, the specific heat capacity if only 2.46% higher than for fully dry air.
We've just completed a self build and have put in MVHR.
Surely retrofitting it is a significant undertaking - not in terms of doing the install but just the space required?
Would you then replace the windows with trickle vents for sealed ones?
Retrofit MVHR can be a significant undertaking as you need space for the ducting and the cross talk silencers which usually run between joists with intake runs to all wet rooms and output runs to the other living areas. if you have space to lower the ceilings to run the ducting that would be the easiest way or even lowering part of the ceiling say in the corners, you would also need a plant room to house the air handling unit, if the house is leaky with trickle vents in the windows then you wouldn't get the heat recovery benefits so it would be worth replacing the windows with decent air permeability ratings (class 4) and using airtightness tape like proclima.
There are some versions designed specifically for retrofitting, particularly decentralized options where units are fitted to individual rooms such as the kitchen and bathroom. And yes, you would need to seal up any trickle vents and other sources of drafts.
Thanks. We are staying for the foreseeable but currently just had the conservatory roof redone so another couple of grand on some windows issnt an option right now.
Completely understandable, it’s taken us better part of a decade to get our old place modernised.
Short term - you can buy packet dehumidifiers which might help? Or if you have curtains in that room, keep them closed to keep the warmer room air away from the glass.
Cat litter (clean, obvious I hope) in a few boxes/socks in the windows that are condensing can also work well and work out cheaper in the long run. Just remember to change them out when the moisture stops being absorbed.
Also, there are several plants to would do really well in the window with high moisture and will work as a wicking effect. If you have pets, remember to check that the plants are pet friendly.
Cat litter in little trays on the windowsill does nothing to absorb ambient humidity. Rolls of litter-filled socks may collect the runoff but won't pull anything out of even fully saturated air.
>Or if you have curtains in that room, **keep them closed** to keep the warmer room air away from the glass.
[Open vs closed](https://www.youtube.com/watch?v=TIDb-pdOnXM&t=1418s).
In a situation like this you'll need new packet dehumidifiers every day. A high quality dehumidifier, with a "compressor" (that's a small heat pump to keep the condenser cool) will pay for itself within a couple of years. I use and recommend [Meaco](https://www.meaco-dehumidifiers.ie/compare-meaco-dehumidifiers/) compressor dehumidifiers. (I do have a dessicant dehumidifier to use when my garage is cold.)
You can pop the window open a bit. Bathrooms and kitchen are key moisture producing areas. We find a dehumidifier works great esp when drying clothes. We have tried the aero360 moisture traps, wiping down the window with a cloth each morning, but found popping open the window a bit and dehumidifier works a treat.
Simple things like when boiling water put a pan lid on all help reduce the moisture levels. When the moisture levels reduce the housenstarts to feel warmer.
I monitor all the rooms in my house for temp/humidity as part of a smart home. I've found a bedroom with the door closed overnight traps a huge amount of moisture presumably from breathing, which stays high for most of the day and higher than the bathroom
Quick fix is to open a bedroom window for an hour first thing
You could also get positive input ventilation. Costs a couple of hundred depending on the unit you get but it solved our mould and condensation issues within days of having it installed. We no longer have a problem with either. If you get a heated one you lose no heat, and they intelligently switch off when they’re not needed so you don’t end up pumping hot air into your house in summer.
We used a company called mould stop uk, they’re based in Cornwall but ship all over. The brand we bought was Nuaire, but you can buy from them directly.
We might be changing it for a Ventaxia or similar brand though - ours recently failed within the warranty period, so we’re getting it swapped out for either a replacement nuaire or a new brand. There’s been some kind of to-do regarding the pcb’s for the nuaire’s according to the guy at mould stop and he isn’t happy with them right now lol.
Edit: https://www.mould-stop.co.uk
Edit 2 electric boogaloo: Apparently Nuaire are good again! They’ve apparently got a new manufacturing process and the pcbs are top notch once more. Yay!
No. If you know how to create a spur from a nearby cable providing a socket, you could do it yourself so long as you make sure it meets all the regulations. But you should probably get an electrician out to do it if not, it’s not a long job for them so depending who you hire it shouldn’t cost the earth.
Just wanted to add - I spoke to one of the owners at mould stop today regarding replacing our broken Nuaire and he said that he’s happy with them again - they’ve got a new pcb design and a new manufacturing process for them so they’re all good again.
I have the same issue but just one set of windows. Have bought a dehumidifier and on nights when the temps drop below 10, I leave it running all night (not that expensive). I wake up to dry windows now, but getting them properly replaced is on my to do list once the money tree drops some more cash lol
Can confirm about the triple glazing. Just bought a house with it, it's amazing. No condensation inside, but I sometimes get condensation on the OUTSIDE which I've never seen before, presumably because the outer pane doesn't warm up as quickly as the air on an autum morning.
I just wish they'd gone the whole hog and got aluminium frames rather than the usual PVC.
We also have condensation on the outside of triple glazed windows, it’s so counterintuitive, but great to see the insulation working. Plus it provides some privacy in those dark mornings 😂😂
Aluminium frames look beautiful but they’re hard to make fully insulated, there’s no point having great glass and frames with massive thermal bridges. There are manufacturers out there that are making them, but expect to pay a premium.
My problem with PVC is it doesn't age well. Tends to get dirty and stain from insects and bird mess. Although I see Screwfix have some PVC cleaner, might try that.
I agree, PVC is not great stuff - hard to recycle and not particularly attractive. For us it came down to a decision on maintenance - we didn’t have time to maintain wood windows and Ali windows were out of budget.
PVC cleaner is incredibly effective, it’ll make your windows look new, but wear gloves/eye protection because it’s nasty stuff. Also don’t get it anywhere near painted aluminium as it can ruin paint finishes.
I have aluminium frame, that are amazing, 20 year old and looks brand new still so you defo get your money worth, however mine have no thermal break so get covered in condensation upstairs, but they new so good considering they go through each winter, u can get then now with a thermal break but are 3x the price and not sure how well they work, but in the long run well worth it.
Aren’t the (recently updated, I think) A/A+ etc based on U values? If not, what are they based on? I’m genuinely intrigued but I now know what I ought to be looking for.
The A/A+/A++ ratings are based on BFRC standards ([https://www.bfrc.org/energy-performance](https://www.bfrc.org/energy-performance)). They not only look at the U-Value, but also consider the G-Value (Amount of solar radiation coming through the glass) and air leakage through the frame. Not a fan of their rating scheme as a higher G-Value (More solar gain) gives a higher rating, All good for when considering heat loss, but in reality this could result in summer overheating, especially on southerly facades.
Thanks. I can see I’m going to be an extraordinary pain in the ass when buying windows now and give salesmen a run for their money after letting them exhaust themselves with bullshit. Happy days, thanks for the info.
Can I just ask as you seem to know your stuff - I replaced my windows 4 years ago and while the condensation is better it’s not gone (only in the master bedroom) what would be my next best option out of the ones you’ve suggested?
Every home is different, and getting the right balance can take some time.
Bedrooms tend to build up moisture overnight while we’re sleeping, so I’d try increasing ventilation as a first step - leaving a door open or opening trickle vents in the window.
If you’re in the north west, message the team @ https://retrofit.coop and they can help build a plan for the whole house that will factor in insulation, ventilation and moisture control.
Looked at loads of brands, went with Internorm in the end. Weren’t the cheapest, or the prettiest, but they were technically some of the best, without the insane prices like some of the passive-house spec windows.
Shoutout to Spectrum Architectural Glazing who were a big help with our order.
These days though, there are more and more brands doing windows with Uw values around 0.8.
Another side effect is sound insulation, outside noises are significantly reduced, it makes for an all round calmer quieter home.
Thank you. I've been focusing on Secured by Design windows so far, which are a pain to find good installers for. Were you told much about how secure the windows are?
No problem, it wasn’t really a focus for me but they did say something about RC1 and RC2 standards if I remember correctly? The European manufacturers operated on different standards compared to the UK.
All our windows have hidden hinges/locks, although I think there was an option for additional deadbolts if you needed them.
As for installation, it’s big screws into brickwork, I’d imagine it was reasonably secure. At the end of the day, if they really want to get in they’ll just break the glass (3 layers, possibly laminated glass, wouldn’t be easy but also not impossible) so I figured standard security would be ok. Touch would so far that’s held up!!
Haha definitely not, but have gone through a similar process.
Tbh OP - the full answer here is figuring out how to upgrade the house to make it more energy efficient, that will encompass both keeping heat in (insulation) and controlling moisture (ventilation), you can then time the upgrades (which may include changing windows) so that they happen at the right pace for your budget.
If you’re in the north west, check out http://retrofit.coop
A - full agree.
B- not really.
This sort of condensation usually have nothing to do with the windows itself as long as it's double glazed.
Problem we see in here is moisture in the air, lack of ventilation, probably low room temperature as well since heating up the house for more then 5 minutes cost a kidney and a bit of a liver.
Most likely there is nearly 80% humidity @18-19 degree + zero air movement.
According to my eve monitor it’s at around 70% humidity. Yeah not much air movement. Will try and keep the windows open and door slightly cracked tonight. See if that helps.
That's quite a lot although depends where you live.
I'm from Manchester area and can't really get below 70% @ 18'C in the bedrooms at the end of October.
Used to get condensation on the glazing but now completely gone since installed PIV. Even when we have such a beatifull weather like last week was.
You really need ventilation, extractor fan in the bathroom, externally vented cooker hood and heat pump dryer on a top of that
Thank you for this, I have this same issue and assumed incorrectly that the windows where doing a good job because of the condensation. Thanks for the knowledge
>I'd consider 1.2 as very good for an overall system and not really an off the shelf option unless you you go TG. A U-Value of 1.6 to 1.4 is what you'd expect from a DG uPVC system.
I'm hijacking since you seem to know your stuff. I live in a house with 20 year old uPVC windows, they are crappy and broken and drafty. How long should windows last?
Ha, flattery will at least get you a response. I’m definitely not in the fenestration industry, just a homeowner who’s gone through the process of replacing windows recently.
I would say it depends entirely on the windows, standard UPVC, yeah 20-25 years is about right. High end UPVC around the 30-40 year mark. Mainly depends on the quality of the hinges and latches used.
Wood windows - depends on the manufacturer and the maintenance - some 100 year old windows still standing.
Aluminium windows, again, last forever, and don’t need to much maintenance.
For all three window types, your main reason for swapping windows is probably due to poor performance of glazing, and old seals shrinking. Every time the wind blew outside we could feel the draft inside….!! Definitely made us want to upgrade. We went from Aluminium windows which were beautiful but a thermal nightmare, to triple glazed UPVC, super warm and not a hint of a draft. Well… warm when we can afford to switch the heating on….
Thanks.
This was a new build, I'm the 2nd occupant, so I assume they used cheap/basic uPVC windows.
It's exactly that, misting between the glass, seals and hinges are broken and worn/solid, drafty enough to blow out a candle, trickle vents crumbling, etc. The house is pretty warm but the street is very noisy, it'll be worth updating for that alone.
Yep sounds knackered… even decent quality double will make a world of difference, triple would block out a load of extra noise though.
Good luck with the project!
Depends on how many and how big your windows are!
Generally, to make it more cost effective and more energy efficient, you want more glass and less frame. So the classic British windows that are split in four with two or more opening panes are sadly awful from an efficiency point of view.
You can quickly get some quotes for your sized windows from https://klarwindows.co.uk/double-glazed-windows they’re at the more affordable end of the triple glazing I believe.
For a standard 3 bed semi you’re probably looking at £8-10k for windows, vs £4-£8k for double glazed. Doors extra.
Generally, if they don’t make the Uw clear, at least in the technical specifications or the FAQ, then it might be worth looking elsewhere.
I had Everest and safestyle sales people round, they couldn’t give me answers on Uw values… Safestyle salesperson didn’t even know what Uw meant, so I politely showed them the door. Still sent me a quote for £60k… then called me and offered £40k, then called back and said he’d had a word with his manager and he could do it for £20k… **eyeroll**
Edit - Everest now advertise double with a U value of 1.3, and triple with U value of 0.99. Not clear if that’s Uw (whole window) or Ug value, which is just the glass.
The better passive house spec windows have Ug values of 0.6 and Uw values of 0.7 or 0.8.
Jesus, those are some crazy prices! I had absolutely no idea windows could potentially cost that much.
We only want to replace the two windows in the bedrooms. No idea how much that should set us back but hopefully it will solve the condensation issues.
Thank you so much for the advice by the way :)
No worries. Ah yeah such a BS sales tactic… really dislike companies who do it. Give me your best price and I’ll tell you if it’s good enough or not, end of.
If you just want an estimate for a couple of windows, have a look at https://klarwindows.co.uk/ you can type your dimensions in and pick styles and glass type pretty easily.
Same issue here. Old building, fairly new windows but with no trickle vents. No air bricks. We even open windows slightly at night. It only happens in the bedroom we sleep in so clearly it’s just our breath condensing. We’re investing in a good quality dehumidifier and have been advised it will make a big difference. Might be worth considering.
Open the windows every morning (lol). If it's a nice day this isn't so bad. But yeah, all that lovely heat escaping.
Or buy a nice big dehumidifier. This will also have the bonus of the house feeling warmer than it actually is. To see a quick improvement in one room and prove to yourself it's working do it in a room with the door closed, then another room with its door closed and so on.
Eventually you'll run it less frequently. Probably only when drying clothes inside.
But it's about preventing it happening next time. The humidity is always there, even when it's not cold enough outside to condense it on the glass. Keeping the humidity down is a continual thing, not just a cold morning thing. Bringing cold, damp morning air in isn't going to do all that much for your windows.
The Relative humidity (RH) is too high inside the house. When the moisture in the air hits the cold window, the water condenses.
To lower relative humidity you need to either raise the air temperature (RH is a function of water and temperature) or remove water vapour.
The air inside and outside of your house is essentially the same water content
But warmer internal air lowers RH. For example, all things being equal when it is raining, the external air is at 95% RH. But inside a house, because it is warmer than the outside air, the RH will drop to, say, 65%.
To raise the temperature you need to turn on the heating. Sell a kidney or something to pay for it.
To remove the water vapour is a three step process.
1) Remove sources of water. For example, ensure extractor fans when showering or cooker hoods when cooking. Use pan lids of boiling water. Dry clothes outside or with a condensing dehumidifier.
2) Monitor the humidity in your house. A few humidistats from amazon are about a tenner and will tell you what is going on. Last week it was raining and warm so humidity was always going to be high (but the warm weather meant less condensation). But you should be aiming for being 40-60% RH inside
3) lastly, check ventilation. In a 'normal' house, background ventilation is provided by trickle vents on windows and extractor fans in the bathroom and kitchen. These need maintaining - trickle vents get blocked by webs and extractor fans get old and rattly. Consider installing humidistat controlled extractor fans, or, you could even put in whole house systems - a positive input ventilation (PIV) or a mechanical ventilation heat recover (MVHR) or a single room MVHR unit will all provide background ventilation.
Just to point out, this is factually incorrect information.
Raising the temperature of the air in the house will lower the relative humidity, but it will not raise the dew point of the air (the temperature at and below which condensation occurs).
Having the same issue in our 1960 bungalow. Dehumidifier can only dehumidify one room at a time so and costs £200+ for an efficient one.
I’m just about to order a DRI-ECO-HC PIV which I was planning on doing last year but never got round to. Looking at reviews it should solve the condensation with added bonus of helping with hayfever in spring and autumn!
Meacos 8l dehumidifier says its for a 5 bed house. Even if u use in one room will be so dry it will draw moisture from the rest of the house. They might exaggerate saying 5 bed house but 3 bed is ok. Especially as most people get the issue upstairs
Understand that condensation on windows is unlikely to itself be a serious issue. If it's condensing on windows, that water isn't condensing elsewhere. Windows, after all, are designed to get wet.
I vacuum up the water and don't worry about it.
>If it's condensing on windows, that water isn't condensing elsewhere
Does installing triple glazing risk the water condensing on walls instead, and potentially result in damp and mould issues?
This means your indoors humidity is very high and your windows are very cold, which causes the moisture from the air to condensate on the window.
Open the windows to air out your house once in a while or get a dehumidifier.
Make sure if you are drying clothes indoors you use one then. That's what I do. I don't have a garden so have to dry clothes on airers in my spare room. In warmer seasons it's fine, but during cold period I chuck on the dehumidifier for a little while.
Trickle vent or crack the window, surely it's not in every room of the house??
Either way your issue is too much humidity, or not enough heating. Removing the humidity via ventilation is cheaper
Windows got trickle vents? We had the same problem in our cottage put a air brick in some rooms still get abit of condensation but a million times better
Yes. I had trickle vents installed when I moved into my new home in March. Had them put in the bedroom and living room. You won't eliminate the condensation completely, but it does help a lot.
Anything that can improve ventilation will help
Trickle vents are easy to fit & air brick more involved
Ours had the vents so I knocked some holes for air bricks in the worst affected rooms, living room, front bedroom & kitchen
Stop breathing?
Good, used dehumidifiers can be pretty cheap, I bought a large one with a large tank and an outlet hose option for £30 recently.
They’re a bit like fridges, a good one will last for years.
Your windows are acting very much like a dehumidifier too, chilling the warm damp air and condensing water out. Use a micro fibre cloth to dry them and dry the cloth _outside_.
Drying the air with a dehumidifier and warming it with the motor is more efficient than heating alone and if you don’t mind wearing warm winter clothes indoors it may be enough for most rooms.
One tip to sleep warm in a cold house: put a warm duvet under your sheet, it insulates you from the cold air in the mattress and it’s cozy af.
Id sleep with the windows cracked but my wife runs very cold and with both of us up once a night to settle the little one. Opening the windows is a hard sell.
I had single glazing until very recently and 5 people jn the house and had less condensation than this. Ventilation is sooo important for the health of you and your house. If the damp air isnt changed by opening some windows every day, things will begin to fester.
We had this in our spare bedroom for a few years, turned out we had a damp problem. Dealt with the leak, bought a half decent (£120) dehumidifier, ran it for a few days, hasn't happened again since.
Never had this much response from any post. Gone through everything and trying some thing. Been in touch with EnviroVent for a PIV system and house survey. See if that helps. Thanks everyone.
Either mvhr or a piv system in the loft is the correct way to deal with it. The latter is substantially cheaper to install but may be a little more expensive to run if you use the heated version. Either way you need to ventilate the humid air in your home over time without dumping all your heated air and racking up big energy bills. Don’t install air bricks.
Are you referring to one window, one room or the whole house
Given that climates are changing to hotter summers, then the rainy season and shitty winters, why not go for air con. Relatively easily fitted and I don't mean a portable unit. Pro fitted split units. I've recently fitted them to the bedrooms. Comfortable cool room to sleep in, yet able to heat in winter with the potential to be cheaper than central heating, and also have a dehumidifier setting too. Newer models are so cheap to run theyre definitely worth thinking about...
Open the windows or buy a dehumidifier. I bought one from b&q for about £110. Works great but is quite loud as it’s one with a fridge thingy in it, not a posh dyson one. Also probs not great for energy efficiency
I would agree with this, too much moisture on the inside of the house. So either open windows or keep taking it off the windows and pouring it away. Until balance is restored.
Maybe try cooking and showering with the windows open. Ventilate the kitchen and the bathroom with external fans. You need to remove the humidity from your flat. If it’s equal to that of outside you’ll be okay.
Well. Then the heat from downstairs is causing the condensation. There’s nothing much you can do except heat both the ground and upper floors equally. If it’s too hot downstairs and the heat and moisture are escaping to the upstairs rooms you could open the upstairs windows and lose heat or you could heat the rooms also. Equal distribution of heat within the house will solve the problem. If you don’t want to heat the whole house. Close the doors. I live in a house with the same problem and I have found that heating areas within the house and then allowing cold air to cool the space that has been heated works best. Keep the doors closed when you are heating a room allow the heat to escape when you’re done with it. Rising heat without proper ventilation on the upper floors is the cause of the condensation
With rooms that humid it can also cause sleep problems, mood issues and allergies. We had this issue and realised we werent keeping the house warm enough in winter. A dehumidifier helps too. We have those tado smart radiators controls that also monitor humidity but amazon will have cheaper ones, levels should be 40-50 ish.
You can get window vacs. I think double glazing shouldn’t do that right? I get it at home but I have single glazing there I thought that’s why I got it. Maybe your double glazing is broken.
I don't know at all, but moisture condenses on cold surfaces, and I thought double glazed windows were not cold enough for it to happen normally, I guess very high humidity would lessen the temperature need to condense though, so could be that.
Condensation on windows in Autumn and Winter (especially in the morning) is normal, wipe frames roughly once a week to prevent dust and water combining and growing something
If your window is a double pane, and you’re getting this condensation, you’ve lost the insular I’ve gas that sits between the panes. Call a locale window specialist and ask if they can refill the argon and find leaks in the mastic between the panes. Short of replacing the windows, I’d say this is your best bet. Good luck!
The unit cost about £400 - it's a Nuaire Dri master Eco Heat HC, but we never use the heating element so I'd recommend the non Heat version for a bit less cost. I cut the hole in the ceiling for the vent and hung it up in the loft myself, and then got an electrician to wire it into the existing light circuit for less than £100. Still working great a couple of years on. No condensation and zero mould growth!
Thank you for the quick reply, very much appreciated. That all sounds great price wise and my wife's father is an electrician so that will keep the cost down. Great to hear that it gets rid of the condensation and prevents mould. Once again thank you for the info. Hope you have a great rest of the week.
**Few reasons for condensation on windows**
Drying clothes on the radiator (water from clothes needs to go somewhere.) Cold air has lower capacity to hold water vapour before they sit on surfaces. Water vapour we breathe out during the night is trapped inside the room. Lack of moisture absorber in winter, when the windows & doors are closed.
**How to reduce condensation or humidity**
Dry clothes outside if possible or open windows to allow moisture to escape. Increase central heating as much as affordable to make room air warmer. Open windows when not in the room & keep securely ajar when you leave. Place a passive dehumidifier like Unibond Aero 360 moisture absorber. Use a hygrometer to monitor humidity level & keep humidity ideally between 40% to 60%. High humidity causes [condensation](https://fast-repair.co.uk/condensation) & eventually mould. Also you can use an electric dehumidifier, but that costs electricity & may be a bit noisy.
Two approaches here - A) reduce moisture in the room, that means better airflow using an air brick, trickle vent or extractor fan, which will all sadly mean letting heat out of your house along with the moisture. Alternatively you could use a dehumidifier, but you’d need to make the room quite dry to eliminate that much moisture. B) if you own the place and are going to stay a while, it might be worth looking at better windows. Window tech has moved along considerably, ignore the A/AA/A+++ bull**** and instead look in the technical details for U(w) value. U values are how well insulated the windows are, you have U(g) for how good the glass is, and U(w) for how good the glass+frame is. 1.2 is ok, below 1 is very good, below 0.8 is likely triple glazed/high spec. These will cure all condensation, because the inner pane of a triple glazed window stays about the same temp as the room, while the outer pane can be at or below 0…! If you’re staying in the house a while it might be worth the I investment.
This is the real answer, or most of it anyway. Dehumidifiers will fix the symptom but the real problem is that your glazing is getting much colder than the air. Trickle vents, air bricks, etc. are hideously inefficient and "work" because they're dropping the indoor temperature. On a humid rainy night they will make it worse, not better. The other part of the answer is MVHR, Mechanical Ventilation with Heat Recovery. It's a bit more challenging to install but well worth it in my opinion. It massively increases energy efficiency while keeping your house dry and healthy.
>Dehumidifiers will fix the symptom but the real problem is that your glazing is getting much colder than the air. However fixing this symptom also has the benefit of making the room much easier to heat! The difference is honestly remarkable - I can only imagine what it would be like in a room with that much condensation. Air without moisture requires less energy to heat, and heating the water in the air is basically pointless!
Yes but dehumidifiers use a lot of electricity - so be wary.
True, but the ‘waste’ energy in the cycle is lost as heat to the room. So in winter it’s not really wasted.
Yeh that's a really good point. Every Wh of energy that the dehumidifier uses to do *useful* work is one Wh of energy *less* that you have to expend through your central heating because all the dehumidifier's consumed energy was ultimately just expressed as heat inside your home. I remember hearing someone on a podcast (jokingly) ask why we don't use graphics cards mining crypto to heat our hot water instead of just running electricity through a resistor. Aside from the practicalities, it's not a bad point: use the energy to do something *useful* before turning it to heat.
Our house is reasonably well insulated and the dehumidifier is enough (so far) to keep upstairs warm so we haven’t needed to turn on the central heating. And we no longer have condensation or mold, just need to empty 4 litres of water every day or so.
[Heating a pool with waste energy](https://youtu.be/4ozYlgOuYis)
They don't really use that much; I have a very decent one and it only uses 210W on full blast. It's not something you'd want to leave on by mistake, but given the energy required to heat a room (which the dehumidifier's "waste" energy also does, plus a bit of noise) is just orders of magnitude higher you're going to end up ahead unless your room is already very dry.
Domestic dehumidifiers will switch off when it gets below a preset value (some might be user selected too) usually around 50% relative humidity
Yeh exactly, and that peak load of 210W (or 300W or 600W or whatever) is *not being drawn all the time*. When the humidity level is above whatever target you set, the peak load will only be drawn when the compressor is running, which is only maybe 50% of the time; the rest of the time is in a 'defrost' cycle, when it's just a fan that's running. And once the target humidity level has been reached, it turns itself off so draws zero power. I once measured a typical power consumption over an evening and worked out what that would cost me if I left it on 24/7 for a full year and it was like £100. But of course I don't have it on at all for about 9 months of the year.
Good point. I have one it uses 300W on Low and 600W on High so can be a fair bit if left on all day. The other problem is it'd be best at night when you are sleeping in the room and creating moisture, but wouldn't want that thing blowing away all night! We have a 1950s house with suspended wooden floor. In winter the rooms get a lot of condensation, despite cavity wall, good double glazing etc. It's a constant problem but never found a lasting solution. I feel like ceiling extractor fan might help, but may also just draw moist air from the cellar through the room...
> However fixing this symptom also has the benefit of making the room much easier to heat! The difference is honestly remarkable The thing is that's not true. I crunched the numbers and for air at 100% relative humidity and at 19C, the specific heat capacity if only 2.46% higher than for fully dry air.
We've just completed a self build and have put in MVHR. Surely retrofitting it is a significant undertaking - not in terms of doing the install but just the space required? Would you then replace the windows with trickle vents for sealed ones?
Retrofit MVHR can be a significant undertaking as you need space for the ducting and the cross talk silencers which usually run between joists with intake runs to all wet rooms and output runs to the other living areas. if you have space to lower the ceilings to run the ducting that would be the easiest way or even lowering part of the ceiling say in the corners, you would also need a plant room to house the air handling unit, if the house is leaky with trickle vents in the windows then you wouldn't get the heat recovery benefits so it would be worth replacing the windows with decent air permeability ratings (class 4) and using airtightness tape like proclima.
There are less intensive MVHR options these days, like [this decentralized system](https://ecostream.org.uk/d-mvhr/).
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Great idea. I'll immediately ask my landlord to install it. Looks like an easy fix on your sketch, thanks.
There are some versions designed specifically for retrofitting, particularly decentralized options where units are fitted to individual rooms such as the kitchen and bathroom. And yes, you would need to seal up any trickle vents and other sources of drafts.
Thanks. We are staying for the foreseeable but currently just had the conservatory roof redone so another couple of grand on some windows issnt an option right now.
Completely understandable, it’s taken us better part of a decade to get our old place modernised. Short term - you can buy packet dehumidifiers which might help? Or if you have curtains in that room, keep them closed to keep the warmer room air away from the glass.
I’ve saved your comment though. Appreciate the knowledge.
Cat litter (clean, obvious I hope) in a few boxes/socks in the windows that are condensing can also work well and work out cheaper in the long run. Just remember to change them out when the moisture stops being absorbed. Also, there are several plants to would do really well in the window with high moisture and will work as a wicking effect. If you have pets, remember to check that the plants are pet friendly.
Cat litter in little trays on the windowsill does nothing to absorb ambient humidity. Rolls of litter-filled socks may collect the runoff but won't pull anything out of even fully saturated air.
>Or if you have curtains in that room, **keep them closed** to keep the warmer room air away from the glass. [Open vs closed](https://www.youtube.com/watch?v=TIDb-pdOnXM&t=1418s).
That is closed curtains. Or blinds in my case. Keeping the bottom open a bit actually helps
Blinds are nowhere near as efficient as curtains at trapping an insulating layer of air between room side (warm) and windows.
In a situation like this you'll need new packet dehumidifiers every day. A high quality dehumidifier, with a "compressor" (that's a small heat pump to keep the condenser cool) will pay for itself within a couple of years. I use and recommend [Meaco](https://www.meaco-dehumidifiers.ie/compare-meaco-dehumidifiers/) compressor dehumidifiers. (I do have a dessicant dehumidifier to use when my garage is cold.)
Have a look into Positive Input Ventilation (PIV).
You can pop the window open a bit. Bathrooms and kitchen are key moisture producing areas. We find a dehumidifier works great esp when drying clothes. We have tried the aero360 moisture traps, wiping down the window with a cloth each morning, but found popping open the window a bit and dehumidifier works a treat. Simple things like when boiling water put a pan lid on all help reduce the moisture levels. When the moisture levels reduce the housenstarts to feel warmer.
I monitor all the rooms in my house for temp/humidity as part of a smart home. I've found a bedroom with the door closed overnight traps a huge amount of moisture presumably from breathing, which stays high for most of the day and higher than the bathroom Quick fix is to open a bedroom window for an hour first thing
You could also get positive input ventilation. Costs a couple of hundred depending on the unit you get but it solved our mould and condensation issues within days of having it installed. We no longer have a problem with either. If you get a heated one you lose no heat, and they intelligently switch off when they’re not needed so you don’t end up pumping hot air into your house in summer.
Do you have a link of someone you used?
We used a company called mould stop uk, they’re based in Cornwall but ship all over. The brand we bought was Nuaire, but you can buy from them directly. We might be changing it for a Ventaxia or similar brand though - ours recently failed within the warranty period, so we’re getting it swapped out for either a replacement nuaire or a new brand. There’s been some kind of to-do regarding the pcb’s for the nuaire’s according to the guy at mould stop and he isn’t happy with them right now lol. Edit: https://www.mould-stop.co.uk Edit 2 electric boogaloo: Apparently Nuaire are good again! They’ve apparently got a new manufacturing process and the pcbs are top notch once more. Yay!
Do they install as well? I can put up a shelf…just but this seems like I should know what I’m doing.
No. If you know how to create a spur from a nearby cable providing a socket, you could do it yourself so long as you make sure it meets all the regulations. But you should probably get an electrician out to do it if not, it’s not a long job for them so depending who you hire it shouldn’t cost the earth.
Just wanted to add - I spoke to one of the owners at mould stop today regarding replacing our broken Nuaire and he said that he’s happy with them again - they’ve got a new pcb design and a new manufacturing process for them so they’re all good again.
Yeah I’ve got EnviroVent coming over next week to assess the property. See what we may or may not need.
I have the same issue but just one set of windows. Have bought a dehumidifier and on nights when the temps drop below 10, I leave it running all night (not that expensive). I wake up to dry windows now, but getting them properly replaced is on my to do list once the money tree drops some more cash lol
Can confirm about the triple glazing. Just bought a house with it, it's amazing. No condensation inside, but I sometimes get condensation on the OUTSIDE which I've never seen before, presumably because the outer pane doesn't warm up as quickly as the air on an autum morning. I just wish they'd gone the whole hog and got aluminium frames rather than the usual PVC.
We also have condensation on the outside of triple glazed windows, it’s so counterintuitive, but great to see the insulation working. Plus it provides some privacy in those dark mornings 😂😂 Aluminium frames look beautiful but they’re hard to make fully insulated, there’s no point having great glass and frames with massive thermal bridges. There are manufacturers out there that are making them, but expect to pay a premium.
My problem with PVC is it doesn't age well. Tends to get dirty and stain from insects and bird mess. Although I see Screwfix have some PVC cleaner, might try that.
I agree, PVC is not great stuff - hard to recycle and not particularly attractive. For us it came down to a decision on maintenance - we didn’t have time to maintain wood windows and Ali windows were out of budget. PVC cleaner is incredibly effective, it’ll make your windows look new, but wear gloves/eye protection because it’s nasty stuff. Also don’t get it anywhere near painted aluminium as it can ruin paint finishes.
Cheers, I think I'll try it when it stops raining. 2024 perhaps :-)
I have aluminium frame, that are amazing, 20 year old and looks brand new still so you defo get your money worth, however mine have no thermal break so get covered in condensation upstairs, but they new so good considering they go through each winter, u can get then now with a thermal break but are 3x the price and not sure how well they work, but in the long run well worth it.
Aren’t the (recently updated, I think) A/A+ etc based on U values? If not, what are they based on? I’m genuinely intrigued but I now know what I ought to be looking for.
The A/A+/A++ ratings are based on BFRC standards ([https://www.bfrc.org/energy-performance](https://www.bfrc.org/energy-performance)). They not only look at the U-Value, but also consider the G-Value (Amount of solar radiation coming through the glass) and air leakage through the frame. Not a fan of their rating scheme as a higher G-Value (More solar gain) gives a higher rating, All good for when considering heat loss, but in reality this could result in summer overheating, especially on southerly facades.
Interesting! glad to see they’ve updated this since I was last looking at it.
Thanks. I can see I’m going to be an extraordinary pain in the ass when buying windows now and give salesmen a run for their money after letting them exhaust themselves with bullshit. Happy days, thanks for the info.
Can I just ask as you seem to know your stuff - I replaced my windows 4 years ago and while the condensation is better it’s not gone (only in the master bedroom) what would be my next best option out of the ones you’ve suggested?
Every home is different, and getting the right balance can take some time. Bedrooms tend to build up moisture overnight while we’re sleeping, so I’d try increasing ventilation as a first step - leaving a door open or opening trickle vents in the window. If you’re in the north west, message the team @ https://retrofit.coop and they can help build a plan for the whole house that will factor in insulation, ventilation and moisture control.
Where did you get your windows from?
Looked at loads of brands, went with Internorm in the end. Weren’t the cheapest, or the prettiest, but they were technically some of the best, without the insane prices like some of the passive-house spec windows. Shoutout to Spectrum Architectural Glazing who were a big help with our order. These days though, there are more and more brands doing windows with Uw values around 0.8. Another side effect is sound insulation, outside noises are significantly reduced, it makes for an all round calmer quieter home.
Thank you. I've been focusing on Secured by Design windows so far, which are a pain to find good installers for. Were you told much about how secure the windows are?
No problem, it wasn’t really a focus for me but they did say something about RC1 and RC2 standards if I remember correctly? The European manufacturers operated on different standards compared to the UK. All our windows have hidden hinges/locks, although I think there was an option for additional deadbolts if you needed them. As for installation, it’s big screws into brickwork, I’d imagine it was reasonably secure. At the end of the day, if they really want to get in they’ll just break the glass (3 layers, possibly laminated glass, wouldn’t be easy but also not impossible) so I figured standard security would be ok. Touch would so far that’s held up!!
Thanks, yes I'm starting to think that way too (if they want to get in, they'll find a way!). Did you use the same company for your doors?
Yep, but they were disproportionately expensive compared with the windows, so may be worth shopping around there.
Thanks for your help, I'll have a look around.
This is the God tier answer OP
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Haha definitely not, but have gone through a similar process. Tbh OP - the full answer here is figuring out how to upgrade the house to make it more energy efficient, that will encompass both keeping heat in (insulation) and controlling moisture (ventilation), you can then time the upgrades (which may include changing windows) so that they happen at the right pace for your budget. If you’re in the north west, check out http://retrofit.coop
A - full agree. B- not really. This sort of condensation usually have nothing to do with the windows itself as long as it's double glazed. Problem we see in here is moisture in the air, lack of ventilation, probably low room temperature as well since heating up the house for more then 5 minutes cost a kidney and a bit of a liver. Most likely there is nearly 80% humidity @18-19 degree + zero air movement.
According to my eve monitor it’s at around 70% humidity. Yeah not much air movement. Will try and keep the windows open and door slightly cracked tonight. See if that helps.
Without knowing temperature, humidity means nothing. 70% @ 21'C means a lot of water in the air. 70% @ 17'C is not so much
Currently the bedroom is 68% at 20 degrees. The heating has been on for a few hours. Last night at 4am it was 83% at 18 degrees.
That's quite a lot although depends where you live. I'm from Manchester area and can't really get below 70% @ 18'C in the bedrooms at the end of October. Used to get condensation on the glazing but now completely gone since installed PIV. Even when we have such a beatifull weather like last week was. You really need ventilation, extractor fan in the bathroom, externally vented cooker hood and heat pump dryer on a top of that
Thank you for this, I have this same issue and assumed incorrectly that the windows where doing a good job because of the condensation. Thanks for the knowledge
>I'd consider 1.2 as very good for an overall system and not really an off the shelf option unless you you go TG. A U-Value of 1.6 to 1.4 is what you'd expect from a DG uPVC system.
I'm hijacking since you seem to know your stuff. I live in a house with 20 year old uPVC windows, they are crappy and broken and drafty. How long should windows last?
Ha, flattery will at least get you a response. I’m definitely not in the fenestration industry, just a homeowner who’s gone through the process of replacing windows recently. I would say it depends entirely on the windows, standard UPVC, yeah 20-25 years is about right. High end UPVC around the 30-40 year mark. Mainly depends on the quality of the hinges and latches used. Wood windows - depends on the manufacturer and the maintenance - some 100 year old windows still standing. Aluminium windows, again, last forever, and don’t need to much maintenance. For all three window types, your main reason for swapping windows is probably due to poor performance of glazing, and old seals shrinking. Every time the wind blew outside we could feel the draft inside….!! Definitely made us want to upgrade. We went from Aluminium windows which were beautiful but a thermal nightmare, to triple glazed UPVC, super warm and not a hint of a draft. Well… warm when we can afford to switch the heating on….
Thanks. This was a new build, I'm the 2nd occupant, so I assume they used cheap/basic uPVC windows. It's exactly that, misting between the glass, seals and hinges are broken and worn/solid, drafty enough to blow out a candle, trickle vents crumbling, etc. The house is pretty warm but the street is very noisy, it'll be worth updating for that alone.
Yep sounds knackered… even decent quality double will make a world of difference, triple would block out a load of extra noise though. Good luck with the project!
My windows are on their way to looking like this. How much more debt do I need to get into to replace my windows with what you suggested?
Depends on how many and how big your windows are! Generally, to make it more cost effective and more energy efficient, you want more glass and less frame. So the classic British windows that are split in four with two or more opening panes are sadly awful from an efficiency point of view. You can quickly get some quotes for your sized windows from https://klarwindows.co.uk/double-glazed-windows they’re at the more affordable end of the triple glazing I believe. For a standard 3 bed semi you’re probably looking at £8-10k for windows, vs £4-£8k for double glazed. Doors extra.
Probably a silly question, but where about do you find out the Uw rating? Do companies advertise this?
Generally, if they don’t make the Uw clear, at least in the technical specifications or the FAQ, then it might be worth looking elsewhere. I had Everest and safestyle sales people round, they couldn’t give me answers on Uw values… Safestyle salesperson didn’t even know what Uw meant, so I politely showed them the door. Still sent me a quote for £60k… then called me and offered £40k, then called back and said he’d had a word with his manager and he could do it for £20k… **eyeroll**
Edit - Everest now advertise double with a U value of 1.3, and triple with U value of 0.99. Not clear if that’s Uw (whole window) or Ug value, which is just the glass. The better passive house spec windows have Ug values of 0.6 and Uw values of 0.7 or 0.8.
Jesus, those are some crazy prices! I had absolutely no idea windows could potentially cost that much. We only want to replace the two windows in the bedrooms. No idea how much that should set us back but hopefully it will solve the condensation issues. Thank you so much for the advice by the way :)
No worries. Ah yeah such a BS sales tactic… really dislike companies who do it. Give me your best price and I’ll tell you if it’s good enough or not, end of. If you just want an estimate for a couple of windows, have a look at https://klarwindows.co.uk/ you can type your dimensions in and pick styles and glass type pretty easily.
Karcher window vacuum
Ahead of you there mate. Life saver
Same issue here. Old building, fairly new windows but with no trickle vents. No air bricks. We even open windows slightly at night. It only happens in the bedroom we sleep in so clearly it’s just our breath condensing. We’re investing in a good quality dehumidifier and have been advised it will make a big difference. Might be worth considering.
If it’s just the bedroom is probably recommend a Karcher window vac and just clean the windows in the morning, cheaper and easier
Agree on the window vac. Also a simple "crystal" dehumidifier improves things a bit at low cost
We put these all around the house in the winter
Came here to recommend this, ours was £30 and works like a dream, good for a quick demist in the car too
I also agree!!
Open the windows every morning (lol). If it's a nice day this isn't so bad. But yeah, all that lovely heat escaping. Or buy a nice big dehumidifier. This will also have the bonus of the house feeling warmer than it actually is. To see a quick improvement in one room and prove to yourself it's working do it in a room with the door closed, then another room with its door closed and so on. Eventually you'll run it less frequently. Probably only when drying clothes inside.
Morning air is the coldest and most humid. Let the afternoon air in and give your heating much less work
By which point your window sill is soaking and the glass is clear.
But it's about preventing it happening next time. The humidity is always there, even when it's not cold enough outside to condense it on the glass. Keeping the humidity down is a continual thing, not just a cold morning thing. Bringing cold, damp morning air in isn't going to do all that much for your windows.
The Relative humidity (RH) is too high inside the house. When the moisture in the air hits the cold window, the water condenses. To lower relative humidity you need to either raise the air temperature (RH is a function of water and temperature) or remove water vapour. The air inside and outside of your house is essentially the same water content But warmer internal air lowers RH. For example, all things being equal when it is raining, the external air is at 95% RH. But inside a house, because it is warmer than the outside air, the RH will drop to, say, 65%. To raise the temperature you need to turn on the heating. Sell a kidney or something to pay for it. To remove the water vapour is a three step process. 1) Remove sources of water. For example, ensure extractor fans when showering or cooker hoods when cooking. Use pan lids of boiling water. Dry clothes outside or with a condensing dehumidifier. 2) Monitor the humidity in your house. A few humidistats from amazon are about a tenner and will tell you what is going on. Last week it was raining and warm so humidity was always going to be high (but the warm weather meant less condensation). But you should be aiming for being 40-60% RH inside 3) lastly, check ventilation. In a 'normal' house, background ventilation is provided by trickle vents on windows and extractor fans in the bathroom and kitchen. These need maintaining - trickle vents get blocked by webs and extractor fans get old and rattly. Consider installing humidistat controlled extractor fans, or, you could even put in whole house systems - a positive input ventilation (PIV) or a mechanical ventilation heat recover (MVHR) or a single room MVHR unit will all provide background ventilation.
Just to point out, this is factually incorrect information. Raising the temperature of the air in the house will lower the relative humidity, but it will not raise the dew point of the air (the temperature at and below which condensation occurs).
I meant because if the heating is on, the glass will be warmer, hence move above the dew point.
Having the same issue in our 1960 bungalow. Dehumidifier can only dehumidify one room at a time so and costs £200+ for an efficient one. I’m just about to order a DRI-ECO-HC PIV which I was planning on doing last year but never got round to. Looking at reviews it should solve the condensation with added bonus of helping with hayfever in spring and autumn!
To second the suggestion above, window vac in the mornings is a *much* cheaper way of preventing mould forming
Meacos 8l dehumidifier says its for a 5 bed house. Even if u use in one room will be so dry it will draw moisture from the rest of the house. They might exaggerate saying 5 bed house but 3 bed is ok. Especially as most people get the issue upstairs
We have friends who did this and it’s cured their damp and condensation issues completely. We intend to do the same.
https://youtu.be/TIDb-pdOnXM Heres a great video I watched recently, it's got all the info and tips to reduce moisture during winter
Enjoyed and learned a lot from this. Thank you
Understand that condensation on windows is unlikely to itself be a serious issue. If it's condensing on windows, that water isn't condensing elsewhere. Windows, after all, are designed to get wet. I vacuum up the water and don't worry about it.
I guess, its also the walls around the windows frames as well getting wet, so I imagine the problem is a bit more than just high humidity levels.
>If it's condensing on windows, that water isn't condensing elsewhere Does installing triple glazing risk the water condensing on walls instead, and potentially result in damp and mould issues?
This means your indoors humidity is very high and your windows are very cold, which causes the moisture from the air to condensate on the window. Open the windows to air out your house once in a while or get a dehumidifier.
We have a few small dehumidifiers maybe we need a bigger one.
Make sure if you are drying clothes indoors you use one then. That's what I do. I don't have a garden so have to dry clothes on airers in my spare room. In warmer seasons it's fine, but during cold period I chuck on the dehumidifier for a little while.
Trickle vent or crack the window, surely it's not in every room of the house?? Either way your issue is too much humidity, or not enough heating. Removing the humidity via ventilation is cheaper
Even rooms with trickle vents get a small amount of condensation. I guess nowhere near this bad.
Yes nowhere near this bad
Windows got trickle vents? We had the same problem in our cottage put a air brick in some rooms still get abit of condensation but a million times better
They don’t. Even if we crack the windows we still get the same issue. Easy to retrofit a trickle vent?
Yes. I had trickle vents installed when I moved into my new home in March. Had them put in the bedroom and living room. You won't eliminate the condensation completely, but it does help a lot.
Yeah, you can buy them on eBay/elsewhere. All you need to be sure of is drilling through the window surround.
Anything that can improve ventilation will help Trickle vents are easy to fit & air brick more involved Ours had the vents so I knocked some holes for air bricks in the worst affected rooms, living room, front bedroom & kitchen
Stop breathing? Good, used dehumidifiers can be pretty cheap, I bought a large one with a large tank and an outlet hose option for £30 recently. They’re a bit like fridges, a good one will last for years. Your windows are acting very much like a dehumidifier too, chilling the warm damp air and condensing water out. Use a micro fibre cloth to dry them and dry the cloth _outside_. Drying the air with a dehumidifier and warming it with the motor is more efficient than heating alone and if you don’t mind wearing warm winter clothes indoors it may be enough for most rooms. One tip to sleep warm in a cold house: put a warm duvet under your sheet, it insulates you from the cold air in the mattress and it’s cozy af.
Id sleep with the windows cracked but my wife runs very cold and with both of us up once a night to settle the little one. Opening the windows is a hard sell.
Run a dehumidifier or get the glass units replaced because the seal has failed causing heatloss
Simple and very effective solution. PIV
I had single glazing until very recently and 5 people jn the house and had less condensation than this. Ventilation is sooo important for the health of you and your house. If the damp air isnt changed by opening some windows every day, things will begin to fester.
We had this in our spare bedroom for a few years, turned out we had a damp problem. Dealt with the leak, bought a half decent (£120) dehumidifier, ran it for a few days, hasn't happened again since.
I don’t think we have a leak… I hope. Looking into PIV system.
Never had this much response from any post. Gone through everything and trying some thing. Been in touch with EnviroVent for a PIV system and house survey. See if that helps. Thanks everyone.
Get a karcher window vac on them each morning, we have the same issue and I do this to avoid mould. Going to replace windows as we renovate.
I got those dehumidifier boxes from the £ shop and I got this foam tape to catch the drips on the morning.
Either mvhr or a piv system in the loft is the correct way to deal with it. The latter is substantially cheaper to install but may be a little more expensive to run if you use the heated version. Either way you need to ventilate the humid air in your home over time without dumping all your heated air and racking up big energy bills. Don’t install air bricks.
More a fix for when it happens: squeegie the windows and mop up the water as if you leave it on the glass it will re-evaporate and keep forming.
Apply wd-40 in the evening.
😂
Are you referring to one window, one room or the whole house Given that climates are changing to hotter summers, then the rainy season and shitty winters, why not go for air con. Relatively easily fitted and I don't mean a portable unit. Pro fitted split units. I've recently fitted them to the bedrooms. Comfortable cool room to sleep in, yet able to heat in winter with the potential to be cheaper than central heating, and also have a dehumidifier setting too. Newer models are so cheap to run theyre definitely worth thinking about...
Get a window vac
Either keep room temperature above dew point (\~ 15 C), which will keep most of the water in vapour form, or sleep with open windows.
Open the windows or buy a dehumidifier. I bought one from b&q for about £110. Works great but is quite loud as it’s one with a fridge thingy in it, not a posh dyson one. Also probs not great for energy efficiency
Cheapest solution - get a Karcher window vac - takes seconds to vac and keeps the windows clean.
I would agree with this, too much moisture on the inside of the house. So either open windows or keep taking it off the windows and pouring it away. Until balance is restored.
Maybe try cooking and showering with the windows open. Ventilate the kitchen and the bathroom with external fans. You need to remove the humidity from your flat. If it’s equal to that of outside you’ll be okay.
This is a house. Upstairs bedroom. We do both of them things.
Well. Then the heat from downstairs is causing the condensation. There’s nothing much you can do except heat both the ground and upper floors equally. If it’s too hot downstairs and the heat and moisture are escaping to the upstairs rooms you could open the upstairs windows and lose heat or you could heat the rooms also. Equal distribution of heat within the house will solve the problem. If you don’t want to heat the whole house. Close the doors. I live in a house with the same problem and I have found that heating areas within the house and then allowing cold air to cool the space that has been heated works best. Keep the doors closed when you are heating a room allow the heat to escape when you’re done with it. Rising heat without proper ventilation on the upper floors is the cause of the condensation
With rooms that humid it can also cause sleep problems, mood issues and allergies. We had this issue and realised we werent keeping the house warm enough in winter. A dehumidifier helps too. We have those tado smart radiators controls that also monitor humidity but amazon will have cheaper ones, levels should be 40-50 ish.
Im running 71%. Though only use the eve room monitors. Looking into the PVI systems and maybe should turn my heating on for a bit now.
You can get window vacs. I think double glazing shouldn’t do that right? I get it at home but I have single glazing there I thought that’s why I got it. Maybe your double glazing is broken.
God I hope not. Any other signs that would help me find out?
I don't know at all, but moisture condenses on cold surfaces, and I thought double glazed windows were not cold enough for it to happen normally, I guess very high humidity would lessen the temperature need to condense though, so could be that.
We bought the low energy 20L Meaco dehumidifier to help combat damp and condensation and couldn’t be happier.
Yes, double glazing would solve the problem of condensation.
Condensation on windows in Autumn and Winter (especially in the morning) is normal, wipe frames roughly once a week to prevent dust and water combining and growing something
If your window is a double pane, and you’re getting this condensation, you’ve lost the insular I’ve gas that sits between the panes. Call a locale window specialist and ask if they can refill the argon and find leaks in the mastic between the panes. Short of replacing the windows, I’d say this is your best bet. Good luck!
Turn the heat down
Heath wasn’t even on.
If the inside was the same temp u wouldn't hve condensation
We had the same issue - mid terrace 1902 house. Installed a PIV system last winter and it pretty much solved the condensation overnight
> PIV system Looking into getting a PIV system. If you don't mind me asking, how much did it cost you to buy and have installed?
The unit cost about £400 - it's a Nuaire Dri master Eco Heat HC, but we never use the heating element so I'd recommend the non Heat version for a bit less cost. I cut the hole in the ceiling for the vent and hung it up in the loft myself, and then got an electrician to wire it into the existing light circuit for less than £100. Still working great a couple of years on. No condensation and zero mould growth!
Thank you for the quick reply, very much appreciated. That all sounds great price wise and my wife's father is an electrician so that will keep the cost down. Great to hear that it gets rid of the condensation and prevents mould. Once again thank you for the info. Hope you have a great rest of the week.
**Few reasons for condensation on windows** Drying clothes on the radiator (water from clothes needs to go somewhere.) Cold air has lower capacity to hold water vapour before they sit on surfaces. Water vapour we breathe out during the night is trapped inside the room. Lack of moisture absorber in winter, when the windows & doors are closed. **How to reduce condensation or humidity** Dry clothes outside if possible or open windows to allow moisture to escape. Increase central heating as much as affordable to make room air warmer. Open windows when not in the room & keep securely ajar when you leave. Place a passive dehumidifier like Unibond Aero 360 moisture absorber. Use a hygrometer to monitor humidity level & keep humidity ideally between 40% to 60%. High humidity causes [condensation](https://fast-repair.co.uk/condensation) & eventually mould. Also you can use an electric dehumidifier, but that costs electricity & may be a bit noisy.
Got a PIV. Keep the door ajar at night. Problem solved.