Knowing how to check whether your windows and doors are performing at the highest level required is a necessary skill that you should possess as a homeowner. Your windows and doors’ efficiency is vital to the home because you can use their efficiency to evaluate the home’s capacity to lose or gain heat. Inefficient windows and doors will likely cause you to spend extra money on the heating and cooling system in your home. Here are some of the methods to measure the energy efficiency of your windows.
The U-factor, also known as the U-value, is a measure of how efficient and effective the insulating property of a material is functioning. The U-factor of a window or door is described as the rate at which it conducts heat flow. The frames and window spacer material are also considered when measuring the U-factor of a window to obtain the window’s overall efficiency. The lower the U-factor of a window, the higher its energy efficiency.
- Solar Heat Gain Coefficient
The SHGC is another way to measure the energy efficiency of windows and doors. The solar heat gain coefficient is the fraction of solar energy that passes through windows and doors, and later released into the home as heat energy. Windows with high SHGC are more energy efficient during the cold season by absorbing more heat from the sun, while those with low SHGC are more energy efficient in the hot season because they reduce heat gain from the sun.
- Visible Transmittance
The optical property of windows and doors that shows the amount of natural light passing through the window is Visible Transmittance. The VT value of windows and doors lies between a value of 0 and 1. Windows with high VT usually transmit more light.
The relationship between SGHC and VT is measured by the Light-to-solar gain, which relates to a window’s efficiency in transmitting visible light to its ability to reduce the heat energy being absorbed.
- Air Leakage or Infiltration
Air leakage refers to the loss of air that occurs in a window system due to cracks and openings in the window, and it is measured in cubic-feet-per-minute (cfm/sq. ft). Air leakage can be controlled in windows and doors to ensure ventilation in the home. However, windows with air leakages that are higher than 0.30 cfm/sq. ft should be avoided.
- Condensation Resistance
The condensation resistance of a window is a measure of how efficient the window is at resisting the formation of condensation on the window’s surface. The CR value is usually affected by the home’s temperature and the dampness of the outside air.
Measuring the energy efficiency may require the use of tools that may not be readily available to you but, you can hire a window replacement company in your area for professional services.