I can’t tell you how many times I have been to a home putting solar screens on to the windows of the home, and I have felt cold air blasting out the bottom of the window. What I find quite often from people, is they have a tendency to not close their Windows all the way. From the inside of the home, the customer may think the window is closed all the way but it is not. I encourage all customers to make it a habit of latching the lock on the window in the closed position, this way you know for sure your window is closed all the way. There is a particular kind of window here in town that has a 2 inch piece of metal on the inside of the window. It is that metal that does not allow you to see whether or not your Window is closed all the way. It is these windows that I all the time see being open. From the inside of your home you think the Window is closed all the way, but it is not. So often, I will bring this to a customer’s attention, and the customer will say but I have locked the window, or by the customer thinks they have locked and close the window. The window is not actually latched, sure they have turned the latch, but because the Windows not closed all the way, the latch is not properly engaged. a lot of these windows, have a lot of rubber molding at the bottom of the window, so that when a customer closes the window, the rubber of the bottom of the window hits the bottom window seal, and the customer thinks the window is closed. Another easy way is, what you closure window and latch it, simply try opening it again.