Roof windows with heating - what's in it?

Heating systems for skylights are a quite new invention. However, they can certainly have their advantages. Which systems are there, where they can be used effectively and what you can expect when using for cost, you will learn in this post.

Benefits of window heating

Temperature differences wall window

In well-insulated attic roof windows are usually the thermotechnical weak point.

While insulated roof surfaces have U-values ​​of around 0.20 W / (m²K), even new skylights are rarely available with U-values ​​below 1.0 W / (m²K). Older skylights still have significantly worse U-values. For many, the insulation of the glass rim is very poorly executed.

Roof windows with heating - what's in it?: roof

There is therefore a significant difference in temperature between the inner wall surface and the glass surface, which cools strongly when the outside temperature is cold. Particularly in the edge area of ​​the pane, where the insulation is even worse, especially cold temperatures prevail.

Air currents that hit there cool suddenly and severely. This can cause condensation to form. The pane fogs up, condensation can also drip down and moisten the building fabric. In addition, mold can arise. Other problems are the result:

  • the lifetime of the roof windows is limited
  • harmful mold can spread better due to the permanent moisture
  • it must be ventilated frequently to remove the moisture, which in turn leads to further heat loss

Effect of window heating

A window heating heats the glass surface and in particular the edge region of the window electrically so far that a condensation is reliably avoided.

The control of the heating is usually done with a thermostat. So only as much heat is generated as is actually needed. The system can be easily installed by yourself.

Energy costs for the roof window heating

The resulting energy costs are always to be seen relatively, since about two-thirds of the generated heat are also radiated into the room, and thus effectively support the existing heating. The heat is thus used practically twice.

Decisive for the heating costs are the perimeters of the respective windows. With five skylights each 3.5 m in circumference, the annual electricity costs are around 40 - 60 EUR for all windows together during the entire heating season.

Tips & Tricks

The window heating may be one way to postpone replacement of the skylights even though they have poor U-values.

Video Board: Skylights l home improvements, attic ladders, heating under floor, roof windows