Researchers Demonstrate Low‑Cost Aluminum‑Foil Window Cooling

Polish scientists tested a simple, inexpensive method to reduce indoor overheating by covering a sun‑exposed window with a sheet of aluminum foil secured with transparent adhesive tape. The technique exploits passive radiative cooling, allowing heat to be radiated outward rather than retained inside the room. Field trials in Los Angeles showed that the foil reduced window‑side temperatures by several degrees, and performance improved further with an additional protective layer that limited heat gain from surrounding air.

The researchers highlighted that the transparent tape performed better than white paper in directing heat away, making the solution cheap and readily available for households facing extreme heat. They suggested the approach could serve as a reference point for testing more advanced cooling coatings in laboratory settings.