Here we are in November and the sun is still heating up our rooms. The sun is still strong and our rooms with southern exposure get more exposure with the sun lower in the sky. Window films are designed to reduce direct heat gain. Window films do not cool the space. Window films allow the air conditioner to cool the space easier. Therefore, if the A/C is not cooling the space, some heat can still gain the room. If there is some air moving or cool air moving as there would be in the summer, window film will allow the A/C to cool the space easier. So, the purpose of window films is to reduce cooling costs. We may still have to cool the space, even in the Arizona winter, window films will allow us to cool that space easier. Home and Office Tinting and Blinds, Surprise, AZ

Heat gain is common in the winter and many people like the free heat from the sun, so, those will still get that solar heat gain. The concern for winter sun can be the damage to flooring and furnishings, from the sun shining deeper into the home. Window films can provide UV protection without being dark.