Awesome! Sounds like a great lecture you went to. Can I pick your brains on the Enerlogic window film? I haven't heard of it before. We got Magnetite (retrofit quasi double glazing) installed on a few windows and the skylight earlier this year. Not sure how much it helped with reducing heat loss over winter but it's certainly made our house much quieter (I hate noise so much).
With the Enerlogic window film, did you get it installed on all windows or just ones facing particular directions? And are you comfortable to share (PM or in this thread) approximate cost of it?And is it particularly noticeable, ie is it like putting sunglasses on all your windows or is the impact more subtle. Sounds pretty awesome if it works as claimed (I just did a quick google).
I was originally only going to have the Enerlogic installed on our bedroom and family room windows, which all face north towards the winter sun (in the Southern Hemisphere), but ended up doing the whole lot as that got me a good price and, from what I read, there is benefit to windows of any orientation, just not as much as North facing.
Cost was $144 per square metre, which is about double the cost of standard solar tinting that is designed to keep the sun out, not heat in. All up cost was $4K, which may sound a lot but it was significantly cheaper than other alternatives to treat windows for heat retention, namely add on double glazing at $500 per square metre and window replacement double glazing which was $1000-$1500 per square metre!
As a good mustachian, I put some maths I found on a sustainability forum behind these costs and calculated that it should save me just over $400 per year through retained heat in winter and rejected solar radiation in summer. ie a 10 year ROI, which is just on the limit of what I am prepared to invest in such upgrades. (The ROI time frame I stated in my previous post was based on the combination of all upgrades).
The Enerlogic 70 film is more about heat retention than solar rejection, so it is not a particularly dark film and is slightly yellowish to look through (we don't notice it anymore). It still allows 50% of solar radiation through, which you want as much of in winter to provide passive heating. Interestingly, we didn't find it made much of a difference in the temperature the house dropped to overnight in winter, as our house was already reasonably well insulated before I started and we use thick curtains, some with pelmets, at night. The biggest difference was in daytime heat retention and, just like with double glazing, we can no longer feel the outside cold when you stand close to windows, which allowed us to drop the room temperature as we no longer had to compensate for this.
While it is only spring now, we had quite a hot week last week, with temperatures getting up to 31C for two of the days. Without any cooling utilised, the highest the internal temperature of the house got to was 22C on these days, which is a good couple of degrees cooler than what we would have achieved before all these upgrades. It's still early days, but this only helps confirm that these upgrades have been worthwhile.