2.1.9 Installation of efficient windows (double glazing with aluminium frames with thermal break)

This measure consists in the replacement of inefficient windows (e.g. aluminium frame without thermal brake and single glazing) for an efficient one with double glazing and aluminium frames with thermal brake. A typical transmittance of this type of windows is between U=2.2  W/m²K and U=3.5  W/m²K compared to the transmittance of inefficient windows which typical is higher than 4 W/m²K

Initial investment: high. It can be estimated an average cost of about 1500€ for each window, but this price vary greatly, depending on the size of the window and manufacturers. Energy costs are reduced.

• Thermal convection in double glazed windows with structured gap:
  www.sciencedirect.com/science/article/pii/S0378778811001551
• Low heat loss double-glazed windows:
  www.sciencedirect.com/science/article/pii/0360544287900429