The best Louisville window to keep out cold air is an energy efficient window. However, each different type of window also has varying degrees of air leakage rates that effect how well they keep the cold air out of your house.So what is the best type of Louisville you can choose to keep the cold air out?Different Types of Louisville WindowsThere are 6 different types of windows that you can have installed in your home. These include awning windows, fixed windows, casement windows, hopper windows, single or double-hung windows, and single or double-sliding windows.The difference between the windows is that each opens a different way:

Awning: This window is hinged at the top and opens outward.Fixed: These windows do not open.Casement: These windows are hinged on the side and also open outward, like the awning windows.Hopper: This type of window looks like the old bins that open from the top and then you scoop out the contents. It is hinged on the bottom and also opens outwards, with the open part of the window at the top.Single or double-hung: The sashes on these types of windows slide vertically from top down or the bottom up.Single or double-sliding: The sashes in these windows slide horizontally.The Varying Degrees of Air Leakage in Louisville WindowsEven if each of the 6 different types of windows had the exact same energy-efficient glass in them, because of how each is installed and operated they all have different air leakage rates. If there is air leakage, that means that the cold winter air is getting in during the winter and driving up your heating bill; because it is also letting the warm air out.In the summer, this air leakage is letting your air conditioned air out and the hot summer air in making it harder and more expensive to cool your home.For each type of window, here is how they rate for air leakage per energy.gov:Awning: Low leakage rates due to the sash pressing to the frame when closed.Fixed: The lowest leakage rate because they don’t open.Casement: Low leakage rate for the same reason as the awning windows.Hopper: Low leakage rate for the same reason as the awning windows.Single or double-hung: Higher leakage rates than the projecting (awning, hopper, casement) or fixed Louisville windows.Single or double-sliding: Higher leakage rates than the projecting (awning, hopper, casement) or fixed Louisville windows.