There are several types of window frames available for replacement windows. The most common are aluminum frames. Aluminum frames have several positive aspects;
they are lightweight, strong, and durable, as well as low-maintenance. When you think of aluminum window frames, many people imagine dual gray metal; this is no
longer the case. Aluminum frames are now available in a verity of factory-baked enamel colors, which will complement any color scheme.

The major disadvantage with aluminum window frames is its ability to conducts heat and cold. Aluminum significantly increases the total U-factor of the window. In hot climate areas, where solar gain is significant, you may wish to consider using a higher-performance glazing system. In cold climates, aluminum frames may become cold enough to cause moisture or frost to condense on the inside of the windows.

Aluminum window fames with Thermal Break:
Thermal breaks are the frequent answer to the problem of heat conduction with aluminum frames. Thermal break divide the frame into interior and exterior parts, then use a material to join them that is less conductive, such as plastic. Standard thermal breaks have reduced the U-factor of the aluminum frame.