In the last 10 years the windows have had a great technological development mainly aimed at containing energy losses:
- the thickness of the door and frame are increased to improve the thermal insulation;
- now use only low emissive glass with argon gas to reduce the thermal transmittance;
- the study of the knots and the seals has much limited the losses of air.
Today we can therefore proudly say that the Italian window is positioned as performance at the highest European levels.
But what do we find if we analyze the whole window system, including the connection knot between the frame and the subframe (secondary node) and between the subframe and wall (primary node)? Frequently there is a situation of this kind:
- energy-efficient windows (e.g. 68 x 80 mm windows with 2 seals) mounted on wooden counter frames that are practically the same as those used 30 years ago
- the escape between the subframe and the wall filled with the plaster while knowing that the mortar does not adhere to the wood and therefore in time will form a crack through which will pass both the air and the steam, nullifying all the work of waterproofing the doors.
- the connection knot between the frame and the frame entrusted to the sealing with the only polyurethane foam that over time ages quickly and the silicone that after a few years will detach on one of the two sides.
It is clear that a laying of this type makes unnecessary the energy improvement of modern windows and will lose that economic saving in the management that the buyer wanted.
The use of these modern methods of sealing the windows to the wall becomes indispensable if you want to realize buildings to high energy efficiency: the final verification with the blow door test would otherwise put in light the losses from the perimeter.
This is why we ask our customers and designers to collaborate from the design stages to achieve an optimal result.