How much energy can I save by adding reflective film to my windows?

Today I’ve been asked if we take a floor of a high rise building, can we save money if we apply a UV and infrared reflecting film, only the windows that are south facing. (I.E In the northern hemisphere with the sun shining on the windows all day)

The answer is yes you can.

How much energy can be saved with window films

So if we apply a mirror finish film with metallic content or something more technologically advanced with ceramic layers how much would be saved.

From my research of popular large manufacturers of UV and infrared blocking glass films, they say that there is not just a benefit in the summer but also they work in the opposite way in the winter keeping the heat in.

So the savings for window film in the summer are?

In the summer a building covered in glass panels or windows can see a saving of 70% to a maximum of 80% in cooling costs.

In the winter the same building can save up to 30% in heat recovery through reduced heat losses.

So what are the drawbacks.

If you’re in a building block and you’re only renting one floor then applying a gold or copper coloured tinted film may not go down well with the neighbours or the building owners. (there are now films that get around this obvious problem, but with some reduction in efficiency)

There can be a noticeable reduction in light transmission into the building which in turn can act against the green credentials of the product if you’re living in a city that has clouds for 80% of the year. As you’ll need to turn on the lights sooner due to dim lighting inside.

What is the payback period of applying a film product to windows in a large glass faced building.

The answer is dependent on many factors, such as which way the building faces, how much is glass, how many layers of glass are in the wall etc. It can be seen that the payback can be made between 1.5 years and 2 years. Which depending on your business tenancy outlook is worth considering as a green carbon reducing initiative that can save carbon year after year, once the payback is achieved.

So now that I’ve understood the bare principles, all I need to do is help the company decide on which film to buy.