According to the US government’s Department of Energy, sun rays through windows are responsible for around a third of the heat which a building must keep out to maintain room temperature at an acceptable level (cooling load).
Reducing this cooling load would help to maintain comfortable temperatures. An obvious way to do this would be to apply solar film to the windows of the building in question. This is because the film reflects and absorbs heat. Here at National Window Films, we’re here to show how this simple, but ingenious stuff works:
Solar film blocks radiation from the sun. This solar energy comes in three parts: ultraviolet (3%), infrared (53%), and visible light (44%). When sun rays hit a window, the glass absorbs 5% of the solar rays, and reflects 6%. Yet the remaining 89% of the rays make their way through the glass.
When this energy enters a space, it combines with the existing heat from people, computers and that being retransmitted from carpets and furniture. This excess heat can mean the difference between comfort and discomfort. This is especially true for people or animals sitting near windows.
So how will solar film help?
Solar film increases the amount of solar radiation that a window can absorb and reflect. Solar film consists of a thin metal coating. This can be aluminium, silver, stainless steel, or a mixture of all three to absorb and reflect energy to different degrees.
Most of rays that the window absorbs are reradiated outwards, but some radiates into the building. The best solar film can reject as much as 80% of the extraneous rays which hit a window.
The solar heat gain coefficient (SHGC) is the most accurate way to measure the heat rejection ability of solar film. The SHGC is based on the amount of energy which escapes into a room. This includes both the energy that the glass allows to transmit into the room and the amount that the solar film reradiates into the building.
The ability of solar film to reject visible light and infrared will vary. The type of film that is best for a specific purpose will depend on the goals and required results of those using it.
There is a direct correlation between a reduction in solar heat and the amount of energy needed by air conditioning systems for cooling. This means that using solar film can also help to reduce the cost of your electricity bills.