Hi All, I recently bought an old town house with predominantly west facing single-glazed windows and am now looking at adding an extra glaze to the windows to make it more energy efficient. Due to budget constraints, I'm looking at a DIY project using either acrylic and/or polycarbonate materials for the second glaze. I'm just writing to see if anyone has any recommendations on using the two materials?Can both materials be pre-treated – maybe with a tint?– to block UV and mitigate direct sun?Also, for the sake of better security, is it possible to install the polycarbonate panels on the outside (first floor anyway) effectively? Any tips on the subject would greatly appreciated. Thanks in advance,
Hi,
I have successfully used double walled polycarbonate sheets on the outside of windows as a cheap/light alternative to double glazing.
I sealed the cut ends with clear silicone to trap the air inside & then attached them directly to the glass with more clear silicone just around the outside edge. The view is a bit obscured, but light still gets through & the glass inside doesn't get as cold as it used to, so no condensation.
Regards,
Richard
Hello @fadetoblack
Thanks for sharing your question about double glazing your window. Would it be possible for you to post a few photos of your window frame both inside and outside. This will give our members a better idea of its construction and configuration. We can then make recommendations on how to mount the polycarbonate sheet to your window frame.
If you have any other questions we can help with, please let us know.
Eric
Hello @RichardC
Welcome to the Bunnings Workshop community. It's wonderful to have you join us, and thank you for sharing your knowledge and experience regarding double glazing your windows.
It's great to hear that you've managed to double glaze your own window with polycarbonate. Would it be possible for you to post a few photos of your project? I'm sure our members would be keen to see how you did it.
Again, thank you for sharing your knowledge and experience regarding double glazing.
Thanks Eric.I just uploaded some images.
Thanks Richard, would it be possible for you to send a photo of this job. Cheers,
Afternoon @fadetoblack
I havnt used polycarbonate materials per say... But have used old CD/DVDs as a glazing to trap air between the window and the edge of the window sill.
Recycled CDs used as window curtain
Previously I had a sheet of white paper stuck to the glass andwa sconcerned when i installe dteh cd's that the temperture would rise. It rose maybe a degree compared to the white paper, it stayed cool through the height of summer even with the door open. It allows light to enter and gives privacy at the same time.
Recycled CDs used as window screen
This one worked extremley well. The foyer is so much cooler in summer and strangely in winter it is warm. Paperclips, Cd's and timber trim plus cup hooks were the materials I used.
I figure the heat/light is trapped between the glass and the reflective surface of the CD's and bounces back out only getting to heat that air in between (havnt used a temp gun on it yet but now you have me thinking)
Would really like to see how you go about with your double glazing. Or maybe even hang a sheet of polycarbonite from the top of the window instead of sealing it?
Dave
Thanks Dave, this sounds like a very creative approach. I’m fascinated by how it all works.
re acrylic or polycarbonate double glaze, there are heaps of videos on YouTube illustrating, - mainly by elderly British people - how to install them and the benefits of doings so.
Hi Eric & fadetoblack,
Initially I attached the double walled polycarbonate panels to the outside of the glass with double-sided tape. That worked fine for a couple of years, but the window is North-facing, the UV got to the tape & one panel fell off, so knowing it worked, I bit the bullet & then attached it with silicone. Obviously you can see the silicone from the inside so a small, consistent bead is best.
My window is in a bathroom, so the partly obscured view in/out isn't a bad thing. I wouldn't use it across a nice view. I think it works best horizontally, not vertically. If vertical, the warm air would gather at the top of the tubes whilst the bottom would get cold. Horizontally prevents this from happening.
Yeah I have gone down that rabbit hole as well 🙂 One thing I try and keep in mind when I am look at English or European stuff is it is from countries a LOT colder then here. So What workes really well for them may only partially work here. I like the idea of sandiching an air gap between two surfaces. Its why curtains do such a good job. And using other materials is something I dont mind trying.
I want to do the same cd/dvd curtain as a seperator for the back of the house in winter. Really i should get some temperture sensors to quantify the information 🙂
Thanks so much Richard.May I ask why you used the corrugated polycarbonate instead of the flat version which is closer to a window pane?
Thank you for posting those extra pictures. It looks like @RichardC used Suntuf Sunlite 8mm x 610mm x 3.0m Clear Twinwall Polycarbonate Roofing and at certain angles it does look like corrugated polycarbonate. But let's wait for Richard's confirmation on what product they used.
In regards to your own project, using the twin wall would be a much better option as it is light weight, easy to cut and install when compared to Perspex. If you are not bothered with the reduction of visibility, installing the twin wall on either the inside or outside should not be an issue.
My best advice is to make sure that the twin wall polycarbonate does not get in the way of the operation of the window. I strongly advise testing it first just to be sure.
Hi fadetoblack & Eric,
You're right Eric, I used the Sunfuf clear twin wall polycarbonate, not corrugated.
As we know, trapped air is a pretty good insulator so by sealing off the cut ends I trapped air in each tube so that is what makes it work.
Hi @RichardC
Thanks for confirming that, I'll tag @fadetoblack to make sure they see your response.
Eric, you're a Bunnings employee.
Hard work & dedication are one thing, but you shouldn't be replying to work emails, ie working at 10pm!
It's all part of the service, I'm happy to help.
Thanks for this, I really appreciate it. clear visibility is important for us, so I think we'll just use the clear, single walled I guess, sheets.
Hi fadetoblack,
Very sensible. The stuff works, but you'd be silly to put it where visibility is important. A single clear sheet on the outside, preferably trapping a layer of air would have to help moderate the temperature of the glass.
It is a lot more work & expense, but if your windows are timber framed, it should also be possible to remove the glass, increase the depth of the rebate & then fit custom made double glazed units. The internal gap between the panes of glass will probably be less than optimal, but it works. The double glazed unit does of course add a fair bit of extra weight. That wasn't a big issue when I did it to a couple of french doors, but I did have to upgrade the springs when I did it to a double hung window. Doing this improved thermal performance, whilst enabling me to preserve the fabric & appearance of my heritage building.
Good luck!
Thanks Richards, This is beginning to sound a bit more complex than I thought, I may look to get a professional in.I initially saw this video, this video, and this thought I might be able to do it on the outside for security reasons. I'm now starting think high quality smash-resistant and solar reduction film might be the way to go instead. Once again, thanks so much for all your tips!
Yes, no easy/obvious solutions I'm afraid!
Obviously you need to be careful not to solve one problem whilst unwittingly creating another, eg a heat reflecting film may be good in the middle of Summer, but may make your place colder in the Winter!
If the main issue you're wishing to address is unwanted heat gain in the Summer, perhaps some way of keeping the sun off the glass, like retractable awnings on the outside could be an option worth exploring?
Improving ventilation can also do a lot to help cool a house. As we know, hot air rises, so perhaps you could add an opening skylight to let that air out whilst drawing in cooler/fresh air from the cooler/shady side of the house?
Thanks Richard
