I recently installed one-way static cling window tint on my bedroom window, thinking it would help keep the heat out. The tint looks like a mirror from the outside, and I followed the instructions by applying the adhesive side directly to the glass after peeling off the protective film. However, I tracked the temperature with my BBQ infrared laser thermometer and was surprised! At night, it measured 3F hotter than an untreated window, and in the morning with direct sunlight, it was a whopping 20F hotter! I took the tint off immediately. What could I have done wrong, or why might this have happened?
3 Answers
It sounds like the tint is doing its job! By absorbing and reflecting light, it's supposed to reduce heat gain in your room. But since some light gets absorbed, it can indeed heat up the window itself, which might be what's affecting those readings. What you should really focus on is the overall room temperature instead of just the window itself.
This is pretty normal! The film might be reflecting more light than a regular window, but it doesn't block all of it, meaning some sunlight gets absorbed and then heats the window. A good way to evaluate the effectiveness of your tint is to track the AC usage compared to outside temperatures with and without the tint. That will help you measure its impact better.
Your infrared thermometer might not have taken the readings correctly. The tint likely prevents a lot of sunlight from straight heating your room, but it can still absorb some energy. The main goal you should be tracking is how this affects your room temperature or your AC usage over time, not just the glass temperatures. Comparing the room’s comfort before and after the tint will give you a clearer picture.