When talking about a R-Factor on replacement windows, a window's thermal resistance is being discussed. R-Factors range from very low (0-1) to very high (4-5), with the higher the number the better. If something has a R-Factor of 1 this mean that it would take 1 minute for 1 degree of heat to be lost through that material. So, a window with an overall R-Factor of 4 would lose 1 degree of heat through it every 4 minutes. When looking for new replacement windows for your home, look for windows with high R-Factors.
Therefore, R-value is the level of resistance of heat flow through a given thickness of material. Still need some help submit a request via our self service page Maintenance & Services.