Almost everyone has felt huge increases in electricity and gas prices. What can you do so that you are not shocked by the energy bill? The answer is trivially simple: invest in energy-efficient window frames that guarantee lower energy consumption and lower costs.
Thanks to new regulations, energy-efficient windows are gradually becoming a standard. The are chosen by private investors and developers building apartment complexes and office buildings. Their heat transmission rates are as low as possible. This means that they are designed specifically to retain the desired indoor temperature in the best possible way. Importantly, energy-efficient woodwork also protects against cold, heat, and moisture from the outside.
Energy-efficient windows have more insulating chambers in the window profile, triple-glazing sealed units, additional seals, and other solutions that increase their thermal insulation. They way they are installed also matters. The process called warm installation allows you to make the most of the factory window insulation properties in later use.
What is the heat transfer coefficient?
The heat transfer coefficient (U) is a primary measure of the energy efficiency of the window. The coefficient for the entire window is denoted as Uw. If you are uncertain about the value or find it difficult to verify it, you should consider looking for another solution.
Before making a final decision regarding a particular window purchase, check whether the manufacturer provides information on the Uw coefficient. If you see Ug instead – the transmittance for the glass itself –, a more favorable value is a lower value.
There are also discrepancies in the U threshold values for an energy-efficient window. Uw = 1.0 W/(m2K) is a common value but 0.9 is also possible. The less, the better.
Conversely, the minimum Uw coefficient for a certified passive window is precisely determined. It is 0.8 W/(m2K) with the g-factor (total solar energy transmittance) at 50%.
With our warmest PVC profile and using glass with warm frames with a coefficient of Ug = 0.5 W/(m2K), we can make a reference window (1230 mm x 1480 mm) with a thermal coefficient of Uw = 0.69 W/(m2K).
Energy efficiency = lower bills
The biggest advantage of energy-efficient windows is that they contribute to lower energy bills. You can pay up to 30 percent less per year. How much you save depends on the quality of the solutions used and the standard of your previous windows.
In addition to the obvious benefits, i.e. cost saving, energy-efficient windows can help reduce the level of noise that enters the house from outside. Well-chosen windows truly increase the value of the property.
Energy-efficient windows are usually equipped with triple-glazed insulating glass. To improve insulation performance, noble gas (argon or krypton) is placed between the glass sheets resulting in the Ug coefficient of no more than 0.7 W/(m2K). The heat transfer coefficient for the Uf profile should not exceed 1.1 W/(m2K). Good thermal insulation is also achieved thanks to the warm frame.