Rob's Home and Garden Blog

Home Insulation: Thermal Efficiency of Your Double Glazed Windows

by Martha Reed

Insulating your home has a significant influence on your comfort. Not only does it help you maintain adequate and pleasant temperatures both in winter and summer, but in due course, optimal thermal insulation will dramatically reduce your hefty energy bills. In this post, discover how you can start your home improvement journey by insulating your house with double glazed windows.

How thermal efficiency is measured

Thermal insulation is measured using a thermal conductivity factor (U-factor). This factor measures temperature exchange that occurs between the exterior and interior of your home. A lower U value means a better insulating window. With windows, two critical elements influence the insulation capacity: the frame and glass type.

Window frames

Materials used for window frames are aluminium, PVC and wood. PVC offers the best thermal insulation, thus highest energy savings. Wood is also a natural insulator and therefore an excellent alternative. Though the initial cost of wood windows is low, maintenance costs are quite high. You can find aluminium frames with thermal bridge breakage. An insulating material (like resin or polyamide) is put between the inner and outer part, which prevents the exchange of cold and hot air. Although this system improves energy efficiency, it doesn't reach the levels of PVC insulation.

Type of glass

Although the frame material is essential, it is your type of glass that has a major impact. Placement of windows with double or triple glazing is a highly recommended alternative to contribute positively to the sustainability and energy-efficiency of your home. Beside restricting heat transfer from either side of the window, the hollow space between the glass helps prevent noise from penetrating the glazing.

Main points to observe when choosing glass is its thickness (the thicker the glass, the greater the insulation capacity) and the distance between crystals. It is considered that 16mm is the optimal thickness. Based on these factors, what options do we find in the market?

•    Simple: this glass is usually used for double-glazed windows and provides basic insulation. Despite having a very competitive price and perfect insulation capacity; on specific issues, such as the thermal bridge, it is not a very efficient glass.

•    Low emissive: ideal for regions with extremely cold winters and mild summers. This type of glass is excellent for conserving heat and preventing cold air from coming in. They also stand out for their ability to reduce condensation and to reject infrared radiation. Although it insulates better than simple glass, low emissivity does not prevent entry of heat. Hence, it is advisable to use low emissive glass with solar control.

•    Solar control: It is the perfect glass for warm climates with mild winters due to its ability to avoid overheating the interior of your home. Although it is very effective in reducing air conditioning expenses; it should only be used in certain cases since they minimise entry of outside light.