Glass Energy Efficiency relies on the SHGC and U-Values. These are the two most commonly used measurements. We’ve provided a brief explanation to help you select the right option for your home.

What is a Solar Heat Gain Coefficient (SHGC)?

SHGC stands for Solar Heat Gain Coefficient. Measuring the SHGC helps us understand how much solar heat is gained through the glass window or door as a result of direct sunlight. When sunlight hits the glass, there is a portion of sunlight that is reflected. The remainder is either absorbed by the glass or transmitted through the glass. The SHGC is a percentage measure of solar heat gain that is transmitted through the glass. It is measured as a number between 0 and 1, with a higher co-efficient meaning that more heat gain will occur. More information can be found here.

To understand how this will affect you it’s important to assess correctly your area of application. For example, If you live in a cold area, you may want to heat your home as naturally as possible. This would mean that a higher rating would be preferred as this would maximise the amount of solar heat transmitted and absorbed. However, if you live in a very sunny area and your home is prone to heating up too much in summer, you may want to limit the transmission of heat. This means that going for a glass type that has a lower SHGC would be preferred.

A lower SHGC will improve the energy rating of your home as it will consistently regulate the temperature better. This means that less power would be required to cool your home when exposed to high solar heat. Your choice depends on your purpose and preferences. A high SHGC may actually suit you and your property!

What is a U-Value?

U-Value is the measure of how much heat energy is transferred through the glass. This is different to how much solar heat gain is transferred as a result of sunlight (SHGC). The U-Value measures the level of conductivity. In other words, it measures the non-solar heat gain or loss. A lower number means the glass (window or door) is better at reducing the transfer of heat.

The U-Value of a window or door is determined by the overall construction of the opening including the glass, frames, seals and any spaces in the window or door. If you opt for a lower U-Value, it means that less heat or cold escapes and/or enters the home, resulting in a better insulating value. Essentially a lower U-Value will mean that less energy is required to maintain and regulate the temperate in the home (as it will not fluctuate as much with outside conditions).

For more detailed information you can refer to the Your Home Government Information and Australian Window Association Information. Stay tuned for our upcoming blog content. We will provide you with some further information about how to improve the thermal rating of your frameless glass doors and windows. If you would like to learn more about our product, refer to here.