Double glazing is an effective solution for reducing heat loss in Australian buildings, particularly in regions with cold winters and hot summers. Heat loss through windows is a significant issue in many homes, and can account for up to 40% of energy loss. By reducing heat loss through windows, double glazing can help homeowners save money on heating bills during winter, and reduce the need for air conditioning during summer.
The Minimum Standards
In Australia, the Building Code of Australia (BCA) sets minimum standards for energy efficiency in buildings, including the use of double glazing in certain climates. The BCA specifies minimum requirements for the U-value of windows, which measures the rate of heat transfer through the material. The U-value for double glazed windows should be no higher than 2.0 W/m²K in climate zones 4, 5, 6, and 7, which covers much of southern and eastern Australia.
When choosing double glazing for an Australian home, it is important to consider factors such as the type of glass used, the gap between the glass panes, and the type of gas used to fill the gap. Low-emissivity (Low-E) glass is a popular choice for double glazing in Australia, as it has a special coating that reflects heat back into the room. Argon gas is commonly used to fill the gap between the glass panes, as it is an effective insulator and readily available in Australia.
Reducing Heat Loss Through Double Glazing
Firstly, it is important to understand how heat is lost from buildings. Heat can escape through the windows, walls, roof, and floor. However, windows are the weakest point in the building envelope and can account for up to 30% of heat loss in a typical home. Single pane windows, in particular, are not effective at retaining heat and can result in significant energy waste and higher heating bills.
Creating a Barrier
Double glazing, on the other hand, is designed to reduce heat loss by creating a thermal barrier between the inside and outside of the building. The gap between the two glass panes acts as an insulating layer that reduces heat transfer. This gap is typically filled with air or gas such as argon, krypton or xenon. These gases are denser than air and provide better insulation, resulting in greater energy efficiency.
The Power of Convection
Double glazing also reduces heat loss through convection. Convection is the transfer of heat through the movement of fluids such as air. When hot air comes into contact with a cold surface, it cools down and sinks to the bottom, while the cooler air rises to take its place. This creates a convection current that can result in significant heat loss.
Double glazing reduces convection by creating a still layer of air or gas between the two glass panes. This still layer acts as a barrier to the movement of air, reducing the formation of convection currents and heat loss.
Another way that double glazing reduces heat loss is by reducing the amount of radiation that can pass through the window. Radiation is the transfer of heat through electromagnetic waves, and it can pass through glass. However, double glazing reduces the amount of radiation that can pass through the window by reflecting it back into the room. This means that less heat is lost through the windows, resulting in a more energy-efficient building.
Save On Electrify Bills
In addition to reducing heat loss, double glazing can also help to reduce electricity bills. By retaining more heat within the building, less energy is required to heat the space, resulting in lower energy bills. This is particularly beneficial in colder climates where heating costs can be a significant expense.
Furthermore, double glazing can also help to reduce the need for air conditioning during hot weather. The insulating properties of double glazing also work in reverse, preventing heat from entering the building during hot weather. This means that the building stays cooler for longer, reducing the need for air conditioning and further reducing energy bills.