How do you stop condensation on windows?

[#1]

Condensation occurs when warm air collides with cold surfaces. It also occurs  when there's too much humidity in your home. It creates water which collects as droplets on a cold surface when humid air is in contact with it.

Some of the sources of humidity in your home are:

• In the shower, if you don't have an exhaust fan to push the humidity out of the bathroom, it will get trapped in the house and will take some time to dissipate.

• In the kitchen, if your range hood is no longer effective, the moisture produced when you cook also gets trapped in the house.

• If your clothes dryer is not properly vented out. The moisture gets trapped in the house.

By venting these three major sources of humidity it will lower the water trapped in your house. You may also use a dehumidifier to lower the humidity in the house such as an Ausclimate 12L Compact Dehumidifier. This unit is rated to handle a 50m2 room. It can be positioned so that moisture gets taken away before it has a chance to settle on the windows.   

Regular venting of the house will allow air to circulate inside and remove the trapped humidity. - EricL

We get condensation on just one window. We have ducted heating, and the ducts are under the windows. My daughter likes it cold in her bedroom, so she closed her duct, and her window started getting condensation. I opened it just a crack, and it stopped happening.

So a little warmth and airflow stops it. I assume a pelmet would reduce the airflow more. Can you try blocking the gap at the top of the curtains to test it? Maybe jam some material in there. - pstq

Condensation is formed from it being colder outside then inside and the humidity being higher inside.

I get most condensation on my windows when I am running my gas heater. It pumps loads of moisture into the air so when that warm air hits the window, it rains.

I also have metal shutters that I put down at night to keep the cold out. It forms a type of double gap (metal, air, window) so I don’t actually get any condensation in the lounge room where the heater is.

Curtains may help with the same air gap but from memory the condensation still builds up. Thick rubber-backed ones would be best.

If I run my heater lower (as in warm up the house then turn it right down) I don’t get anywhere near as much condensation build-up. – Dave-1

Installing heavy curtains to prevent the warm, saturated air within the room from contacting the glass is one way to minimise the effect. The other is to allow airflow from outside into the room during the night, which obviously, given temperatures, isn't something most would want to do.

Don't feel like you're alone, as this is a common occurrence in many homes. I'm wiping my windows down every morning. I also open them up in the morning to allow airflow during the day.

Using a dehumidifier could potentially help reduce the issue by removing moisture from the air. - MitchellMc

Very common problem. The nights are cold and lots of people run heaters which makes the condensation build up. 

If you're looking for a product to use I recommend something similar to these disposable moisture absorbers. They are containers you can place on the windowsill that have crystals in them that draw in moisture and then to water. Once it's full, you just dispose of the liquid and can refill the crystals (you can buy 3kg bags of the crystals to top up as frequently as you like). 

It didn't completely remove the condensation, but we noticed it reduce significantly and then a cloth could wipe up the last of it to prevent any mould. - shaneaoz