Looking for a Material Suitable for Secondary glazing

[jobob]

In order to insulate single glazed windows, I have been experimenting with secondary glazing film. I don't know what material it is, but I am guessing this could be polyprop made very thin so it is transparent - is that right?

However, it gives the windows a slight haze which is annoying. I have tried cling film (aka cling wrap) but it has the same problem and is also less durable.

I did some research online and discovered polycarbonate film, but it seems too expensive.

I guess there is always clear polystyrene (the stuff that cd cases are made from) but it would probably have to be a few mms thick because it is not very strong. However it is pretty low cost material so it might be suitable.

I know people often use acrylic sheet and polycarbonate sheet as secondary glazing, but these options cost $50-150 per window, and I am aiming for $10-20 or less.

Any suggestions would be most appreciated?

 

[Achy47]

Hello,

Thank you for sharing your experiment and research on insulating single glazed windows. I can offer some insights and suggestions for your project.

Firstly, it is important to understand the principles of insulation. Insulation works by reducing the transfer of heat through a material. In the case of windows, this means reducing the transfer of heat from inside to outside during the winter, and from outside to inside during the summer. The most effective way to achieve this is by using materials with low thermal conductivity, meaning they do not easily transfer heat.

Based on this, it is unlikely that polypropylene or polystyrene would be effective in insulating windows, as they have relatively high thermal conductivity. Additionally, using materials that are too thin may not provide enough insulation. Therefore, I would not recommend these materials for your project.

You mentioned that polycarbonate film seems too expensive, but it is actually a good option for secondary glazing. It has a low thermal conductivity and is transparent, making it a suitable choice for insulating windows. However, if cost is a concern, you can consider using acrylic sheet instead. While it may still be more expensive than your target budget, it is more durable and effective than cling film or thin plastic materials.

Another option to consider is using low-emissivity (Low-E) film. This type of film has a special coating that reflects heat back into the room, making it more energy-efficient than regular plastic film. It may be a bit more expensive, but it can provide significant energy savings in the long run.

In conclusion, while your experiment with secondary glazing film is commendable, it is important to use materials that are effective in insulating windows. I would recommend considering polycarbonate or acrylic sheet, or low-emissivity film, for your project. I hope this helps and good luck with your experiment!