The heat loss is almost 40 % of the total heating energy in a one-family dwelling with old windows.
The Uw-value of old single-glazed wooden windows is up to 6,0 W/m²K. That makes up to about 66 litres of heating oil/m²/heating period.
The Uw-value of old insulated plastic windows is 2,6 W/m²K. That makes up to 31 litres heating oil/m²/heating period.
The Uw-value of new insulated plastic windows from REINÜ-FEFA is 1,3 W/m²K. That makes up to 17 litres heating oil/m²/heating period.
Pausaer Straße 69
+49 36628 60158
+49 36628 60159
As legally claimed the thermal insulation value for glass should reach an Ug-value between 1,1 and 1,3 W/m²K. With triple glazing the Uw-value should even be 0,8 W/m²K (Low-energy house).
The thermal image shows the ideal process of the Isotherm.
Ug = Heat transmission coefficient for glass
Uw = Heat transmission coefficient for the complete window