Reduce heat loss with new material

Insulation and thermal bridges are a problem for producers of exterior doors. Doors need to be strong to handle stress of daily use, especially heavy exterior doors in Northern Europe with sub-zero winter temperatures. This has traditionally limited the choice of materials and left door-producers with wood and metal – materials with bad insulation properties.

New types of polymer composites change this. A number of European manufacturers of exterior doors have begun producing highly insulating composite doors, which still have the strength of traditional materials.

The benefit is that the new doors reduce the heat loss from the building.

A little revolution in the industry

And it is not by a small margin. A typical exterior door with a steel frame and a wooden leaf has a thermal transmittance of 0,96 W/m2k. A premium aluminium door with alu frame and leaf has a thermal transmittance of 0,71 W/m2k. The new composite doors, where both leaf and frame are made of plastic composite has a thermal transmittance of 0,65 W/m2k., according to the independent Polish Institute of Building Technics (Instytut Techniki Budowlanej).

“This is a little revolution in the industry,” product specialist Marcin Bloch at Primo in Poland says.

He was a part of the introduction of the composite material in 2020. It all started with customer demand for smarter and greener building materials.

Benefits from the new composite material when used for exterior doors:

• Lower weight
• Better insulation
• Completely recyclable solution

The first recyclable plastic composite

Thanks to rapid development procedures and a market open for new solutions, the new material saw the light of day just after a few months and is now used by four of the main door manufacturers in Poland:

 "You can say this has become a trend and we are already seeing interest from Germany and other countries as well."

The popularity of the new composite can also be attributed to the fact that the material is easily reused.

“Plastic composites have traditionally not been easy to recycle because of the chemical differences in the included materials. That problem is solved, and it opens for entirely new business models. Imagine that people can return their old windows to us, have them regrinded and used to produce new building materials. This is very close at becoming reality,” says Marcin Bloch.

What is U-value?

A U-value is a measure of thermal transmittance, or the amount of heat energy that moves through a floor, wall, or roof, from the warm (heated) side to the cold side. It is the number of Watts per square metre of the construction, per degree of temperature difference between one side and the other (W/m2K). The Ud-value is simply the U-value for doors, while Uw is the U-value for windows. Learn more about the international U-standards here.