Condesation on windows

Help Support House Repair Talk:

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
My house has double pained windows. Temperatures outside are below freezing. I am noticing that there is condensation on them. Specifically, it is the surface to the inside of the house. I can wipe it with a rag.

This house did have a portable dehumidifier, but the old owners took it with them. Is that something that I would need or is this a bigger issue?
 

Bob Reynolds

Well-Known Member
Joined
Oct 8, 2008
Messages
127
Reaction score
72
This could indicate an HVAC problem. Where are you? How old is the house? How old is the heating system? What type of heating system is it?
 

Steve123

Well-Known Member
Joined
Jul 5, 2017
Messages
227
Reaction score
93
This time of year can be about the worst for condensation. The interior still has a fair amount of moisture, and the first cold nights really creates a lot of condensation. Cold winter outdoor air is dry, so before too long, your interior humidity will start dropping. How much your humidity drops depends on how tight your house is, and your lifestyle. Its a good idea to get a hygrometer. But buy a good one -- they can be notoriously inaccurate. You can always check/calibrate it --- just go to Youtube and search "hygrometer salt method".
 

kok328

Well-Known Member
Joined
Nov 19, 2007
Messages
3,070
Reaction score
331
As has been mentioned, we are in the drying out season unless you have a humidifier for the winter months.
You could also be creating more moisture in the air than necessary if you don't run bathroom exhaust fans or do a lot of cooking. You can minimize the condensation by leaving the curtains/drapes/blinds open a little to get warm air flow behind them.
On a more serious side, this could also be a sign of carbon monoxide, indicating a leak or blockage of furnace exhaust and/or a bad heat exchanger.
Always have a CO monitor running during the winter months.
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
This could indicate an HVAC problem. Where are you? How old is the house? How old is the heating system? What type of heating system is it?
1) Northern ON, by a lake that has ice on it.
2) ~90 years old.
3) 5 years old
4) Forced air propane.
 

Sparky617

Member
Joined
Nov 3, 2014
Messages
1,442
Reaction score
514
Location
Cary NC
You may have mentioned it in another post, but given the age what is your foundation? Do you have a basement? Is it dry? What are the walls and floor made of? At 90 years old a rubble-stone foundation wouldn't be unusual same with a dirt floor. A lot of moisture can come up into the house from these conditions. It will naturally condense on the colder windows just as humidity condenses on a cold drink glass/bottle/can in the summer.
 

Bob Reynolds

Well-Known Member
Joined
Oct 8, 2008
Messages
127
Reaction score
72
1) Northern ON, by a lake that has ice on it.
2) ~90 years old.
3) 5 years old
4) Forced air propane.
So this brings up a few more questions....

1. Are some rooms cold and others warm? I've seen homes with ice forming on the inside of a bedroom window while the rest of the house is warm.

2. How is you insulation on this home? I've seen older homes without insulation. Once we properly insulated them then they were able to hold the heat to a proper comfort level.

3. Are you using a lot of propane?
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
You may have mentioned it in another post, but given the age what is your foundation? Do you have a basement? Is it dry? What are the walls and floor made of? At 90 years old a rubble-stone foundation wouldn't be unusual same with a dirt floor. A lot of moisture can come up into the house from these conditions. It will naturally condense on the colder windows just as humidity condenses on a cold drink glass/bottle/can in the summer.
Basement walls are concrete block. Age of foundation is unknown. Floor is concrete. There is part of the floor that is a giant rock.
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
So this brings up a few more questions....

1. Are some rooms cold and others warm? I've seen homes with ice forming on the inside of a bedroom window while the rest of the house is warm.

2. How is you insulation on this home? I've seen older homes without insulation. Once we properly insulated them then they were able to hold the heat to a proper comfort level.

3. Are you using a lot of propane?
All rooms seem to be relatively equally warm.

It's insulated with the fibreglass batting. As I understood the amount from the supplier, it is no worse than a 1970s home I had with NG heat.
 

Sparky617

Member
Joined
Nov 3, 2014
Messages
1,442
Reaction score
514
Location
Cary NC
Basement walls are concrete block. Age of foundation is unknown. Floor is concrete. There is part of the floor that is a giant rock.
You might want to try this test to see if you're getting water vapor into the house from the basement. Tape a piece of aluminum foil or plastic to the wall in several places. Taping all 4 sides, do the same on the floor in several places. If after a few days you have water condensed between the foil and the wall you have water vapor coming into the basement from the outside. In this case painting the basement walls with Thoro-seal or Dryloc may help reduce the water vapor coming in. Adding a dehumidifier in the basement may help as well.
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
You might want to try this test to see if you're getting water vapor into the house from the basement. Tape a piece of aluminum foil or plastic to the wall in several places. Taping all 4 sides, do the same on the floor in several places. If after a few days you have water condensed between the foil and the wall you have water vapor coming into the basement from the outside. In this case painting the basement walls with Thoro-seal or Dryloc may help reduce the water vapor coming in. Adding a dehumidifier in the basement may help as well.
I'll give that a try.
 

Sparky617

Member
Joined
Nov 3, 2014
Messages
1,442
Reaction score
514
Location
Cary NC
Also make sure you use your bathroom fans while showering and exhaust fan in the kitchen when cooking, especially frying and boiling water.
 

Bob Reynolds

Well-Known Member
Joined
Oct 8, 2008
Messages
127
Reaction score
72
All rooms seem to be relatively equally warm.

It's insulated with the fibreglass batting. As I understood the amount from the supplier, it is no worse than a 1970s home I had with NG heat.
If the home is fully insulated properly then I believe you are up to checking the moisture readings in your home. I use this one:


It's under $50 and it will give you an idea areas of unusual moisture. It will also let you know if there is a concentrated problem that you need to address.

You started the original post asking if you need a dehumidifier. I believe the answer is yes.
 

Steve123

Well-Known Member
Joined
Jul 5, 2017
Messages
227
Reaction score
93
If you need a humidifier in the winter, it is unlikely you have excess humidity in your house.

You might be expecting too much from your windows. Just "double pane" means little. Not sure if you can even buy single pane windows in Canada anymore. There might be a label on the windows that identifies the glass unit. The glass units are available in countless permutations of gas fills and coatings. Some of the coatings may decrease heat transfer, but hurt possibility of condensation. Every glass unit will have a "condensation resistance" (CR) rating. As expected, the better units cost more. Actually, if you want the better condensation resistance, you need to go to triple pane.
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
If you need a humidifier in the winter, it is unlikely you have excess humidity in your house.

You might be expecting too much from your windows. Just "double pane" means little. Not sure if you can even buy single pane windows in Canada anymore. There might be a label on the windows that identifies the glass unit. The glass units are available in countless permutations of gas fills and coatings. Some of the coatings may decrease heat transfer, but hurt possibility of condensation. Every glass unit will have a "condensation resistance" (CR) rating. As expected, the better units cost more. Actually, if you want the better condensation resistance, you need to go to triple pane.
I meant at my old house. This house, it seems the reverse.
 

68bucks

Junior Member
Joined
Oct 15, 2015
Messages
184
Reaction score
65
I have a question, is the condensation evenly distributed on the window surface or is it in a circular or oval area more in the center of the pane? I have issues with collapsed glass on some of my windows, double pane Anderson windows. That leaves an oval shaped area of condensation on the window, mainly when it gets closer the low teens F outside.
 

oldognewtrick

Administrator
Staff member
Admin
Moderator
Joined
Jul 26, 2009
Messages
11,696
Reaction score
1,833
Location
Nashville, TN
Are there any air gaps around the window, doors or any opening in the structure? It's easy to check by holding a lit candle close to the window and odsevering the flicker of the flame. Do you know anyone with a FLIR camera? They are great tools for weatherizing homes.
 

swimmer_spe

Well-Known Member
Joined
Apr 29, 2015
Messages
753
Reaction score
131
I have a question, is the condensation evenly distributed on the window surface or is it in a circular or oval area more in the center of the pane? I have issues with collapsed glass on some of my windows, double pane Anderson windows. That leaves an oval shaped area of condensation on the window, mainly when it gets closer the low teens F outside.
It is mainly at the bottom of the pain

Are there any air gaps around the window, doors or any opening in the structure? It's easy to check by holding a lit candle close to the window and odsevering the flicker of the flame. Do you know anyone with a FLIR camera? They are great tools for weatherizing homes.
I wish I did. I don't think there are air gaps.
 

Latest posts

Top