Looks like thermopane.
What is the window frame made of?
What is the humidity like in those rooms?

 

Window frame - not sure. We’re not experts unfortunately in this kind of stuff.
Humidity not sure either. Would the humidity change throughout the day morning and night? My husband says he must have humidity meter somewhere in the garage He will try to find it

 

The house was built in the year 2000 if that helps

 

Water vapour in air condenses to liquid as the temperature decreases. There isn’t anything that you can do about the outdoor temperature, but you can reduce the amount of condensation that happens by:

• Increasing the temperature of the inner window surface. That’s expensive, since it involves outer storm windows or window replacement with more expensive units with decreased heat loss, etc..
• Reducing the water vapour in the air. Most Canadian houses have the opposite problem of not enough indoor air humidity in winter, leading to dry skin, adding humidifiers to HVAC system, etc. It shouldn’t be too hard for you to figure out where the humidity is coming from (not running a bathroom fan when having a shower, not running a kitchen exhaust fan when boiling pasta, etc.)

The reason that the problem appears to be worse in the morning can either because the outdoor temperature (and window inner surface temperature) are lower in the morning, or because something is adding moisture to the air overnight. That would be the case in a room where people are sleeping, since they are exhaling moisture.

 

It also "seems" like your windows are recessed a bit into the wall, wide window sill.
This will limit the air flow from the floor vent across the lower part of the window, especially if the blind blocks the air flow as well.
Check the relative humidity, realize though that most cheap humidistats are way off.

Humidity Sensor Calibration

Humidity Sensor Calibration: I've got 3 sensors that can measure relative humidity of the air: BME280, SHT21, DHT22. They stated ability of measuring with accuracy +/-3% from range 20 to 80% However, when testing in same condition for 3 sensor, i got 3 different results. Maybe …

www.instructables.com

IF there is no apparent source of excess humidity, or not a controllable one, like breathing.

I would suggest one of those inside plastic window films to act as a storm window.

3M Indoor 1-Window Insulation Kit, Clear Window Film for Heat and Cold, 7 ft. x 19.7 ft of film, Covers One XL 6 ft 8 in x 19.5 ft Window - Window Latches - Amazon.com

3M Indoor 1-Window Insulation Kit, Clear Window Film for Heat and Cold, 7 ft. x 19.7 ft of film, Covers One XL 6 ft 8 in x 19.5 ft Window - Window Latches - Amazon.com

www.amazon.com

 

What is the RH of the house?

 

OK thank you guys. Well go buy a humidity checker/testers and go from there

 

Hi Kate,

"We have blinds on all of the windows" might be the most important sentence in your post. Are your blinds closed at night? If so, that is probably the major part of, if not the entire cause of, the condensation that you are seeing. Looking at your pictures and seeing a lot of water on your glass surfaces really feels like closed blinds isolating warmer room air from the windows when closed at night.

Really there is no need for a separate humidity gauge because you already have one. If your windows are wet then there is too much humidity, ultimately that's the only gauge you need.

A humidity gauge will tell you what room relative humidity is and relative humidity can be raised or lowered simply by adjusting room temperature. And while changing room relative humidity might make a person feel more comfortable, changing room temperature does not affect dew point which is based on the amount of moisture in the air and not to room temperature.

When you close the blinds you are creating a micro-environment between the closed blinds and the glass. As it gets colder outside that little airspace is going to get colder and the glass temperature is going to drop below the dew point.

If glass temperature is below the dew point temperature you will have moisture on your windows. This is why closed blinds may be your problem and why using a gauge to measure room temperature and relative humidity is just an added and IMO unnecessary action.

First step in eliminating the window condensation is to try leaving the blinds open at night. Leave at about 6" or so (or 15 cm if you prefer) open and see what happens.

 

Hi Kate,

"We have blinds on all of the windows" might be the most important sentence in your post. Are your blinds closed at night? If so, that is the major part your problem, if not the entire cause of the condensation. Looking at the pictures, that's a lot of water on your glass surfaces and that there is also ice really sounds like it's closed blinds isolating warmer room air from the windows.

There is no need for a separate humidity gauge because you already have one - if your windows are wet then there is too much humidity. That's the only gauge you need.

A humidity gauge will tell you what room relative humidity is and relative humidity can be raised or lowered simply by adjusting room temperature. And while changing room relative humidity might make a person feel more comfortable, changing room temperature does not affect dew point which is based on the amount of moisture in the air and not to room temperature.

When you close the blinds you are creating a micro-environment between the closed blinds and the glass. As it gets colder outside that little airspace is going to get colder and the glass temperature is going to drop below the dew point.

If glass temperature is below the dew point temperature you will have moisture on your windows. This is why closed blinds may be your problem and why using a gauge to measure room temperature and relative humidity is just an added and IMO unnecessary action.

First step in eliminating the window condensation is to try leaving the blinds open at night. Leave at about 6" or so (or 15 cm if you prefer) open and see what happens.

Thank you, actually somebody else on a different forum also said that having drapes or blinds closed at night, will create a problem exactly with that. Here’s the thing: our blinds ARE always closed, we just flip them (not raise up, but turn) during daytime to have lights in and flip back for the night. but they are always down. it’s a very good point and I will leave all the blinds few inches up overnight to see what happens tomorrow….

 

By the way we do not have separate room temperature adjuster. Just one thermostat controlling the heat for the whole house and it’s always set to 21C (22C if weather outside is -20C) during winter time. But 21C has been mostly very comfortable for our house. The house upstairs does feel a little bit cooler than downstairs but that’s probably normal

 

I think Oberon nailed it. We have binds on our windows and have hardly any condensation and no icing, and we get a lot colder than you (house built in '95). Drapes are worse. A hygrometer is like ten or fifteen bucks. You want to be in the 40% range and newer homes decently built are a lot tighter. Indoor humidity comes for a lot of sources; cooking bathing, breathing. Does somebody regularly have a shower before bed? If so, you need to run the bathroom vent for 20-30 minutes after. Do you have a humidifier on your furnace or an HRV? Both have humidity controls.

 

Does somebody regularly have a shower before bed? If so, you need to run the bathroom vent for 20-30 minutes after.

Me and the kids every single night. The fan is always ON DURING the shower and maybe 10-15min after the shower.

Do you have a humidifier on your furnace or an HRV? Both have humidity controls.

Don’t know, don’t see any on the furnace.

 

The picture indicates the window is leaking cold air into the house at the bottom. Attempting to seal those areas would be my 1st plan and go from there.

You have 3 of the 3 requirements in your house to determine relative humidity about as accurate as most purchased meters. Room temperature, a refrigerator and a calculate conversion at your finger tips. If you take a container from the refrigerator and dew forms on the surface you know the temperature of that surface and room temperature. The 3rd thing you need is a conversion chart from your computer to calculate.

 

Can not provide an update for todays morning as the temperature has risen and was around -2 at night and is +3 now, not cold enough to create condensation.
However for Monday, the evening/night forecast is to be below 20C, so on Tuesday morning we will see A) condensation or not B) how much of it

The picture indicates the window is leaking cold air into the house at the bottom. Attempting to seal those areas would be my 1st plan and go from there.

When the weather is very cold, yes you can feel the cold draft at the bottom of the windows. But its normal, in cold weathers. In order to fix it we would have to spend couple of hundred / window for better insulation. Too many windows. Its not ideal, but condensation is a bigger problem in our opinion then a cold air for now.

A decently- built (which may be the rub) 2000-era house shouldn't need window film. Multiple late evening showers might be too much for the vent fan, assuming the fan is working properly.

The fan is working properly. Never had an issue with it. We even vacuum every fan's plastic cover semi-annually (from dust).

Maybe leave it on all night for a couple of nights (when the appropriate weather occurs). It might cost a buck or two in power.

If we leave the fan on for the whole night, but the doors to the bedrooms are closed, will it still help? hypothetically speaking...

I can't tell from the photo but do you get condensation between the glass panes? Is the HVAC vent below the window moving air?

Did not pay attention last time between the glass panes. The supply vent is below the middle window (in each room, there are 3 windows in each room) and the vent is always open.

 

Quickest fix was nailed above - use an interior storm to help block the humid air from getting to that area though that may cause more issues. 1st make sure that area is fully dry before installing & then check the windows in the AM to make sure you don't have ice or lots of condensation forming again - if you do you have issues with humid air still getting into that area. FAQ: Why are my windows / walls wet or have ice on them? (thehtrc.com)

 

A decently- built (which may be the rub) 2000-era house shouldn't need window film. Multiple late evening showers might be too much for the vent fan, assuming the fan is working properly. Maybe leave it on all night for a couple of nights (when the appropriate weather occurs). It might cost a buck or two in power. I can't tell from the photo but do you get condensation between the glass panes? Is the HVAC vent below the window moving air?

 

Here’s the thing: our blinds ARE always closed, we just flip them (not raise up, but turn) during daytime to have lights in and flip back for the night. but they are always down.

Understood, but still comes down to allowing warmer room air access to the windows at night, so you can either raise the closed blinds a few inches or else leave them open all night.

A bit more on using a gauge to measure the Rh and how it relates to window condensation....

Dew point is defined as saturation vapor density, or 100% relative humidity, or as the transition temperature between evaporation and condensation. Dew point temperature is based on the amount of water in the air and is unaffected by air temperature. If you are so inclined the dew point temperature can be found by comparing air temperature to relative humidity on an appropriate chart. You can also do the math of course, but use the chart, trust me on that.

Condensation occurs on windows because the glass temperature is below the dew point temperature of the air. That's it, nothing magic about it. If the window temperature is below the dew point you have condensation, if window temp is above the dew point you don't. That's why you don't want to block warmer room air from the window at night.

In order to control condensation from forming on the surface of a window you either:
(a) lower the dew point to a level below the temperature of the window surface
(b) warm up the window surface to a temperature above the dew point
(c) do both

Consider a home at 65°F with a measured relative humidity reading of 40%. In this scenario there is 6.25 grams of water per cubic meter of air in the home equating to a dew point of 38°F. If the window glass temperature goes below the dew point then it's pretty much a certainty that there will be condensation and maybe even ice formation on the window.

Since (apparently) in this scenario the Rh is too high, we can raise the air temp to 75°F and lower the Rh to 29% which is (apparently) well within the recommended range of Rh to avoid window condensation. So now all is good, right?

Well not so much because lowering the Rh by raising the room temperature did nothing to lower the level of water in the air, it remains 6.25 grams per cubic meter and the dew point is still 38°. So despite measuring 29% on the fancy new Rh gauge, you still have condensation on your windows. So much for using the new gauge.

Your home was built in 2000 and by that time a high percentage of windows were being manufactured with LowE coating and argon, but we don't know if yours were or not. Hopefully they were because that will be a definite factor on how you can control condensation. And since once you open the blinds in the morning the east-facing windows (sunrise) appear to have less condensation than the west-facing windows (shadow), I suspect that your windows might be okay.

Once again leave the blinds open at night and see what happens. Forget "air leakage" at the edge, internal storms, plastic, and so on for the moment, you first need to find out what the closed blinds are doing. Leaving the blinds open will help, but might not be a 100% fix, but at least you will now have a place to start.

 

So last night was -24C in our area and in the morning today we had condensation in all rooms, but MUCH MUCH LESS then before. Here are the photos. So it seems like the blinds did cause the big amount of moisture to appear. Considering that it was super cold last night (right now 10am is -19C), we think this amount right now on the windows is NORMAL for CANADA? lol at least no ice

 

I wouldn't call it "normal". It used to be with older window technology. I used to live in an old place in n/w Ontario and you couldn't see out the windows most days from November until March.

We were -28C last night and only the slightest touch of condensation (2 adults + 2 dogs, double pane glass, 1995 house). It might or might not cause any long-term damage to the windows but it might to the wood trim.

I still think you have a humidity problem, at least in the affected rooms. Leaving the room doors open a crack might help. Even though the HVAC vent is right there, closing doors can impact air circulation to the return ducts which are probably in the hall.

 

We had the same issue couple years ago when we were 6 persons in the house. How we fixed, was to install an HRV (heat recovery ventilation) system in existing heating system and based on that we could control the humidity in the house. No issues since that.