The Window Film Project

The Start ….

The objective of this project is to stop the sun pouring in our east-facing front door on summer mornings, unnecessarily heating the house.  This heating occurs despite double glazed panels in the door.  Over the last few summers, I have hung a flannelette sheet over the front door which has helped to keep some of the heat out, but it isn’t an attractive, finished or permanent option.  The way the house is built, and the type of door, means that outside awnings or inside blinds or shutters or curtains are not options.

I have only recently learnt that quite a lot of sun still comes in windows even though they are double glazed.  It was my observation that this happened, but I didn’t understand why.  I thought the purpose of double glazed windows was to stop heat getting out and sun getting in.  All my research six years ago, prior to building our house, didn’t lead me to understand the point that sun still comes in through double glazing and heats up the inside.  I also thought that we should have the same sort of windows throughout all of the house.  I am not referring here to the style of windows, which is a matter of aesthetics and hence personal preference but, rather, the glazing technology. With double glazed windows, you can now have them manufactured with special films on the outside or inside of each pane of glass.  The type of film, and the surface that it is applied to, will alter the amount of sun allowed into the house.  It is complicated but important to get right.  The best sites that I have found to date are the Windows Energy Rating Scheme site and associated sites that provides a glazing selection tool  and a window selection tool window selection tool. all of these sites have developed a lot in the last few years.

As far as our front door is concerned, I am going to see if we can retrospectively apply a film to the glass to stop the heat coming in.  Obviously the only glass surfaces that a film could be applied to are the inside of the inside pane and the outside of the outside pane, because the double glazing unit is a sealed unit with argon gas in the gap between the panes.  Even if it didn’t have the argon in the gap, these units can’t be dismantled and then reassembled.

And Then ….

I have contacted a local company to find out about the sorts of films that they have that would be suitable for a domestic application but, before I did that, I looked at the site for Applied Film Products.  This site lists accredited installers and WERS rated products but there are no installers in our regional center so I looked up the phone book.  I found a company that very kindly offered to send me some samples which I will look forward to receiving.  Meanwhile, the thick flannelette sheet and drawings pins are doing their job.

The Latest ….

Three samples have arrived and I have taped them to the front door.  Each sample stops a different amount of sun coming in, according to the specification sheet that came with each sample.  All are applied to the inside of the inside piece of glass.  They are different colors though.  My interest is in how they look throughout the day and as well as at night, from both inside and outside the house.  I don’t doubt they will work close to or as specified, because they are rated by WERS, but some films, that I have seen from the outside of houses that we have driven past, look like mirrors or have a color to them that I don’t like.  So time to watch and learn!

To Be Continued ….