How to insulate windows in a rental?

[st22]

I am renting. At night it gets really cold. How can I improve thermal insulation of the windows? They have vertical blinds and a metalic frame for the glass. I think double glazing is too expensive, the landlord isn't interested. What would you recommend?

[MitchellMc]

Hi @st22,

To help prevent the cold from transferring through the windows and into the room, it would be a good idea to install an additional curtain rail or try to use the existing one to hang heavy curtains that span across the window and touch the walls. This helps create a buffer zone where any cold air is contained behind the curtain. 

You should also check for any gaps around the window frame where cold air could be leaking, and those can be filled with gap filler. Here's a helpful step-by-step guide: How to apply silicone sealant. Here's another article on How to winter-proof your home. It's important to remember that although the window might be a source of heat loss, the warmer you can make the rest of the home, the less impactful the lack of thermal insulation on the windows will be.

You might like to read through this guide on How to keep your rental home warm in winter.

I've also just come across this Permastik 2m x 1.2m Blockout Material. Although it's designed as a flyscreen and light blockout device, I see no reason why it would not work as a thermal shield. It will seal the glass pane off completely preventing drafts and air transfer to the room.

Please let me know if you have any questions.

Mitchell
 

[Dave-1]

Morning @st22 

The thing that has worked best for me is rubber back curtains. You can take them down in summer but winter they can come out again. I did an experiment where I have metal venitians across my back room and was given some rubber back curtains. I used them for half the distance of covering the window and it really made a difference to the temperture in winter and summer.

You could install them after your vertical blinds, that way you can still use the ease of blocking with the verticle blinds but for the chill the heavey duties come out.

Dave

[st22]

Hi Mitchell

Thank you for your advice.

I didn't see any gaps to seal. The window frame looks like without gaps.

I am installing thermal curtains now. In one of the rooms with a balcony,with a tall cold window, the thermal curtains work very well. Now doing this for the bedroom.

I did not understand the difference between thermal curtains and blockout curtains?

Other than by having the curtains hang full length to the floor as this is where the cold air goes, how do I ensure the curtains touch the walls and do not leak air?

[st22]

Hi Dave

What do the "metal venitians" do?

My curtains have acrylic coat for thermal insulation and are rather heavy now. I replaced the blinds rather than adding a secobd layer, as in the rental I cannot install an additional rail.

[Dave-1]

Evening @st22 

The metal "Venetian Blinds" are just horizontal slatted blinds, minimal insulation, they block light more then insulate. The rubber back curtains stop the cold and heat coming through a lot better. I was comparing the two different "blinds" in the comment above.

Thermal curtains and blockout curtains are the same just a different name. They stop the heat and cold from coming through.  I find that the heavier they are the more they block. With the question you asked @MitchellMc  the way curtains are made/configured if you have a 1m window width then you would generaly have 2m of bunched curtain material, this gives layers of material and air that forms an insulation barrier and helps stop heat/cold transfer. The straighter the material of the curtain fall as in no ripples the less air pockets for capturing the heat/cold.

By having the curtain material gathered and genneraly the curtain rails extend past the edge of the window it covers that gap between curtain and wall. If you live near a "Spotlight" store they have loads of examples of curtains and how they work, interesting from a "how do they work" perspective

Dave

[st22]

Thanks!