Everyone has one or two rooms in their house that are always hotter than others, consumer expert Angie Hicks says window film is a cheap solution to the problem.

"Cost for adding window film to your windows is dependent on the type of film you use and usually it varies from $6 to $14 per square foot. The total cost is then determined by the number windows and the size of the windows."

The film does more than just keep the heat out.

"Window film is an after-market product applied to your existing windows. It is a polyester base that has different materials sandwiched in between a couple of layers to give different properties. We are typically looking to stop UV, heat and excessive glare" says, Kevin Koval a window film installer.

Among all the other benefits of window film, it also acts as a barrier if someone tries to break into your home by breaking the glass. It will simply splinter and hold together, sort of like when a rock hits your windshield.

Once the film is applied you should wait 30 days for it to adhere to the glass before cleaning and most window film comes with a lifetime warranty.