Solar or Low E films: Are they snake oil or do they actually work?

A former workplace had a glass corridor connecting two buildings, eventually they put solar film on it and it did make a considerable difference.

They also fitted the film to the window of a small room re-purposed as a server room, it made it feel like the evening in the middle of the afternoon.

With all that intercepted UV, how long before the film breaks up, discolours or whatever?

Yes, we put it on the inside of the two windows that face the south-west, and it did help. Didn't do any tests.

It's a pig to put on if you're trying not to get any bubbles.

I once stopped in traffic just west of the Tower of London, and couldn't understand why my right arm felt hot, as the car was in shade. It was the red-looking windows of a tall building across the junction reflecting heat.

Can't say, they vacated the site a couple of years later.

The Walkie Talkie that became the Walkie Scorchie?

No, it wasn't that one, it had a flat face.

Ours has been up at least thirty years, ordinary window glass stops most UV, and this is on the inside of double glazing.

I love my ac

My experience is, which was many years ago, was that they didn't noticeably reduce heating, but the stresses they put on our ancient double glazing units due to the increased temperature difference caused cracking of the uncoated pane and separation of the sealed units.

Dave

Window glass does not have much effect on longer wavelength UV. I can shine my UV torch through most windows and objects inside fluoresce almost as much as with the window open. This applies to modern windows with an IR reflecting film as well as old ones. John

In winter too! :-)

Yes they work fine in summer, rejecting long wavelength IR. However in winter you won't get so much solar gain inside the house. Most double glazed units have low E metallisation deposited on the inside of the outer pane to stop heat loss from the room, working the other way round!