Optimum energy consumption

How to get the optimum energy consumption?
The orientation of your home and the type of window play important roles in your energy consumption. The choice of glass in the window depends on the amount of sun light available.

The orientation of the house
When building a new home is it important to take the orientation of the house into consideration. This is not just about the specific window’s ability to retain heat but also about utilising the free energy from the sun.

North – this façade receives limited sun light and therefore it is important that it has maximum insulation. This means that the windows should have as low a U-value as possible. Rationel offers a triple-glazed window with a U-value down to 0.79. Seen from an energy point of view it is a good solution placing large windows towards the north. This ensures a healthy indoor climate and you avoid the risk of over heating, which you have on the south façade.

South – the most important factor on the south façade is to utilise the available solar energy to heat the house. Choose modern double-glazed energy windows with a good U-value and a high g-value to make use of the free solar heat. The g-value is the window’s ability to let the solar heat through the window and into the house. South façades get more sun light than the other three, which makes it important to have a high g-value. However you have to be careful with large windows towards the south because of the risk of over heating. This can be avoided by using solar shielding such as sun blinds and roller blinds.

East and west – on the east and west façades the sun also contributes with solar heating. Choose modern double-glazed energy windows with a good U-value and a high g-value to make use of the free solar heat. The g-value is the window’s ability to let the solar heat come through the window. Be careful with large windows toward east and west as well. Adjust the number with your needs for heating.

Think green – it’s worthwhile
Most home owners change the windows as the first step when they want to reduce their energy consumption. About 30% of the energy used for heating of older homes is lost through closed windows. 

That is why new and modern windows are one of the best investments when a considerable energy saving must be made for a manageable amount of money.

Yearly saving:

• 1.050 kg CO²
• 395 litre of oil
• 15% on your heating bill per year

Other advantages:

• Reduced CO² omissions
• Better indoor climate
  • Less cold fallout
  • Less draught
  • Better opportunity for ventilation
• New windows that fit the architectural style of your home

The calculations are amde on a 150m² home, when changing the windows from old double-glazed windows to Rationel double-glazed energy windows.