The Department of Energy advises that 10% to 25% of your heating bill is attributed to window efficiency losses. In the summertime, the sun shining through windows can heat homes making air conditioners work two to three times harder. Windows with spectrally selective coatings, such as solar film can help reflect up to 85% of the heat entering your home through the windows, while still allowing in the same amount of light. Additionally, solar screens can save 20% to 35% of the cooling portion of your electric bill, when properly applied, as well as help mitigate the effects of cold winter winds.