To celebrate this first day of Summer 2017, here’s a recap on some ‘heat control window film‘ I recently installed. Quick backstory is ~13 years in NYC and I’ve never had air conditioning. My current home is essentially three rooms: bathroom, small back room, and main ‘room’ that is both the kitchen & the standard living room – this single room is open all the way through, approximately 12′ x 28′. The morning sun hits the small back room, but the bulk of the day’s sun – and thereby heat – hits the roof and eventually the front windows, where the kitchen is located. From the back room to the front room on hot days, you can feel an approximate 8-10°F difference. Air circulation alone doesn’t cut down the heat, which eventually lead me down this path of researching heat reflection, and eventually to this UV/glare-resistant film (I went with the Gila LES361 because it read well, and was one of the first options I saw – turns out there are tons of options to choose from, including patterns, designs, and frost levels).

For starters, here’s a shot of the two (of three) front windows with no film, and the sunlight (mind you this is ‘reflected’ light too – not even direct!) blowing out the exposure:

The reflective film comes in rolls. I bought the 3’x15′ version which I calculated would be enough to cover both sections of 3 windows – so six sections total. (I’ve found my windows are common but not standard, if that makes sense – they’re 24″ x 72″ or so, so curtains are typically too wide and either too short or too long for them, and what you do find to fit windows of this size typically costs a bit more because of their unique framing. But I digress!)

I sized the sections to 36″ (the width of the roll) by 26″ – giving approximately 1″ extra all the way around:

The film – with the aid of the spray-on liquid solution (sodiumdodecylbenzenesulfonate) – pretty much immediately ‘clings’ to the window. Then after smoothing out the bubbles and trimming the edges, you’re left with a pretty obvious difference in light allowance:

For example, it’s pretty obvious which window has the film applied:

That’s a drastic difference! Now I’m really curious how much less light I’ll see with all the windows covered.

The whole process took a bit longer than expected, but once you get the hang of your windows down they will go faster and finish in rapid succession. Eventually I returned my curtains to their rightful place:

…and then came the real test: seeing how much light was reflected!

I went outside and it’s pretty amazing how opaque these things are from the outside, while allowing light in, but reflecting UV and glare:

And one more, here’s an outside-inside comparison, on a very sunny day, where you can see the bottom window section is up, exposing the curtain; but the top half of the curtain cannot even be seen from outside, while inside it still lets light through:

And of course there’s the very subjective opinion: it works. I mean I’ve only really had one mostly-sunny day to test the results, but it’s pretty obvious it works. The film does the job of letting light through while reflecting (or absorbing, more likely) heat; so my apartment is already a couple degrees cooler on days that are mostly warm and sunny – I can feel the difference. The air isn’t as warm, or dry. There’s better airflow from my window fan. And yes, better privacy considering the amount of vision reduced from outside. But mostly it’s the heat. Touching the panels after a good sun-soak you can feel how much heat they absorb; they’re reducing UV and glare, but absorbing straight heat so it doesn’t get inside – light yes, heat no! So if you have windows that get bombarded with sunlight (and therefore heat) you might want to consider this application. I was pleasantly surprised with the results.