I will be leaving my leased condominium in Toronto, Canada for three weeks on 1 Feb. 2019. In cold weather, my window and balcony door sills have pools of water on the floor that sometimes pour into my hardwood floor, much more wringing than the pictures beneath. When I'm here, I sop them up myself. I don't have anyone who can come into my unit daily to soak up.

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Towels don't feel that efficacious to me. Won't they stay water-logged?

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  • 7
    There will likely be much less condensation than usual when you're away. A major source of the moisture is your own breath (as well as any pets and plants).
    – TooTea
    Jan 30, 2019 at 21:02
  • 4
    And your showers, and your cooking. And your humidifier if equipped. Outside air is actually quite dry. Jan 31, 2019 at 0:45

4 Answers 4

  1. Turn on a fan to circulate the air which will remove some of the excess moisture by evaporation.
  2. Change the HVAC filter. A dirty filter will impede air flow.
  3. Turn on the HVAC. This not only cools/heats the room, but also removes humidity.
  4. Get yourself a dehumidifier.

I agree with tootea our breath is a huge amount of the moisture, next showering and cooking, you won't be doing any of that. Turning the heat down will also help you just need to keep things warm, open up cabinets with plumbing and turn the heat down to 50f maybe lower enough to prevent any pipes from freezing but the lowest temp should also help.

  1. Turn off your furnace's humidifier. Because adding water to the air will cause this.
  2. Get rid of the humans. Their breathing, bathing and cooking add moisture.

Between the two, they are the source of this.

The deal is that relative humidity is a different thing than absolute humidity. The difference is, warm air can hold a lot more moisture than cold air.

You are heating your air, greatly increasing its capacity for moisture. You are then adding moisture by breathing, bathing, cooking, or by running a humidifier if your furnace is equipped with one. That greatly increases the absolute humidity in the air, and it can hold a lot because it's warm.

Then, the warm air gets near the window, and chills due to contact with the window. This now-colder air has less capacity to hold moisture, it is driven above 100% humidity so it must condense.

Your house slowly interchanges air with outside through normal leaks (that's why you don't get CO2 poisoning) and it ejects warm, humid air, and intakes subzero, fantastically dry air. Newer homes are much less leaky.

In this case you only want to heat your home enough to keep the pipes from freezing, and you want enough exchange to eject your wet air and admit cold, very dry air. With you not adding any new moisture, window condensation should stop happening.


My old mobile home windows had terrible condensation, some would frost over completely between the glass. I started with sealing my windows every fall with the Duck brand interior window kits, but the real kicker was when I discovered if I took a small plastic cup half filled with driveway (rock)salt and place it between the glass panes, it would stop the moisture build up and the drafts, some windows required 2 or 3 cups half filled with salt. I eventually got new windows and never had to play with plastic again.

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