Misunderstanding 1: Choose dark film
When people choose solar film, in order to obtain better thermal insulation effect and good privacy, they often choose dark-colored solar film. In fact, ordinary "black paper membrane" and "tea paper" are not insulated at all. The thermal insulation effect of the membrane is determined by whether the membrane contains an insulation layer. Although the professional film is light in color, it can block 700 watts of heat under the scorching sun (solar radiation is 900 watts/square meter), while the low-end dark film can only block 300 watts of heat. At present, the films produced in Southeast Asia are basically glue-dyed films. Compared with the metallized films produced in the United States, just like black and white TVs compared to color TVs, the thermal insulation performance is very different.
Misunderstanding 2: Apply two layers of film
Applying two layers of film usually causes the following two problems. First of all, the adhesive design of the film is for sticking on glass, which cannot guarantee the perfect bond between the two layers of film. Secondly, the second film may immediately stick to the first film, leaving no time to squeeze out the moisture. Usually, applying two layers of film is easy to produce bubbles and water pockets, and these will become larger and more numerous over time. In fact, if you need to apply film to make your home darker, you can choose a film with low light transmittance instead of applying two layers.
Misunderstanding 3: Look for the infrared blocking rate
95% infrared blocking rate means 95% heat insulation? This is a wrong concept. Only 53% of the sun's radiant heat comes from infrared rays, another 3% comes from ultraviolet rays, and 44% comes from visible light. So even if a film can block 100% of infrared radiant heat, there is still 47% of solar radiant heat to deal with.