How is Heat Rejection measured?

Total Solar Energy Rejection (TSER) measures the heat rejected by window films. The heat entering through the window is comprised of several different components- 44% visible light, 53% infrared radiation, and 3% ultraviolet energy. The TSER takes into account each part to create a total percentage of heat rejection. The higher the rate, the higher solar energy deflected. 

Most window tint shops use Infra-Red Rejection (IRR) as a guide to the level of heat rejection. However, IRR only covers a fraction of TSER, slightly over 50%. Internationally, TSER is used as a guide for window film standards because it is a more accurate way of measuring heat rejection. The IRR is not an accurate representation of how the window film will perform. For example, if a technician tells you a film blocks 60% of infrared, it only blocks roughly 30% of heat.

Why do some films have higher stats than others?

The majority of window film brands claim that their product is the best. Brands attempt to skew numbers and statistics to mislead the consumer. Often, when a brand of window film only has information about the IR rejection, it is most likely performing subpar. IRR is a number that can be manipulated to read 97-99%, which is very rare for a film to do unless it’s Huper Optik. 

The IR Spectrum for window film covers a wide range (780nm-3000nm). Window Film Manufacturers will pick one small section in that spectrum to measure IRR, usually 900nm-1000nm. They claim that they block 97% of that IR between the two numbers on their selected range. Seems wrong, right? Well, it is. Installers will also use that number alone as their “Heat Rejection.” At autobahn, our top-performing film, Huper Optik Select Drei, blocks 98% of the IR on the full IR spectrum and has a 72% TSER. 

If a company tells you their film blocks 97% of the heat, It will benefit you to call someone else for a quote.

Why is it important for energy savings

The Total Solar Energy Rejection impacts home energy savings. The higher the TSER percentage means that more heat is kept out of your home. Therefore, your AC will use less energy when cooling your home- saving you money. We have seen temperatures reduce by up to 15 – 20 degrees Farenheight with our window films. That results in massive savings for our customers. 

Stay tuned for our next post! We will take on fade control in the home and explain how our window film can help to minimize it as well as keep your furniture and flooring in great shape!

Don’t forget to check out our Residential or Commercial pages for more information on our products!



An XPEL Little Rock Representative will be in touch. For immediate assistance, give us a call!