What every R&D needs to know about Aluminium Window and Ultimate Thermal Performance

By Bogdan Grebenyuk, Product Manager at Thermevo
on May 30, 2018
Series of Articles on Thermal Optimization of Aluminium Systems in Fenestration Industry
"The greater the obstacle, the more glory in overcoming it."

The thermal insulation regulations become increasingly stricter, so thermal insulation of façade components is a means of optimisation the energy efficiency of the building.

Strategy sets the objective to create 20 % of energy consumption from renewables and increasing energy efficiency

by 20 % by 2020 and by 50% by 2050.

As the building sector represents 40% of the European Union's total energy consumption, the energy performance of buildings is a domain where solutions concerning thermal insulation are required.

The main task of an insulating profile, either made from polyamide or polypropylene, is insulation. But the requirements differ depending on the particular purpose. To meet the different needs, THERMEVO offers a wide range of insulating profiles used in aluminium windows, doors and facades. Tо improves thermal performance; a profile can be combined with foam and reinforced with foil, a standard solution. The advantage of our suggestion is that we manufacture both profiles and foam. So foam can be combined with a profile you've chosen and be delivered together.


Head of R&D department, THERMEVO GmbH
Director of Quality Management, GARGIULO GmbH

Choice of materials

The choice of materials is fundamental. Unfortunately, it's not an easy choice. The stable material has poor thermal insulation, and good insulation material has poor stability. So, we need to strike the perfect balance between them to design a stable window.

For example, a balcony window should resist ultraviolet rays. And the whole window system should naturally have a very good U-value to save energy and money as well as meet legal requirements.

Today we are on the brink of systematisation, where the interaction of elements has become more involved, which always implies the development of new materials. In the future, we need to keep up with the innovations to improve interaction and the values. But outside this in the result, we should have a window that will work well and remain functional for many years. It's certainly possible with good stability and good insulation interaction

U-value and energy saving

Norms and standards for are being rarified, and lawmakers demand better insulation value. Therefore, everyone believes in saving energy, and this explains why we choose aluminium windows. There are new opportunities in an isolated foam, in an installation of components, which we cannot even guess now, but we assume that we can improve the system to minimise energy loss, and it would not only save energy, on which we spend our money but also protect the environment.

Profile manufacturing

The process of manufacturing profiles is important because only the interaction of materials and different profiles will result in a good window profile, from which you can create a high-quality box. If we have distortions in production, it will eventually affect the final output that would be the problem no one wants to have.


Let me give you an example. We have an aluminium system and a wide thermal insulation profile with good insulating properties, but then we can't somehow connect them.

It is possible when we deal with products, which are joint in the manufacturing. Typically these are the products from different vendors, with different product quality. This difference can cause a significant problem and substantial deviations in the assembly of the profiles with which the window manufacturer will have to fight. That is what we want to avoid in Gargiulo to produce high-quality products. We make a significant effort to create high-quality products and improve them every day.

System 1.
50 mm+29 mm width, 34 mm Insulating Strip

Pure Insulating Strips

U(f) = 2,16 2
Strips with flags

U(f) = 1,87 3
Strips with flags
and low emission foil
U(f) = 1,76 4
Strips with foam

U(f) = 1,77

System 2.
60 mm+39 mm width, 34 mm Insulating Strip

U(f) = 2,33 2
Strips with flags

U(f) = 2,09 3
Strips with flags
and low emission foil
U(f) = 1,75 4
Strips with foam

U(f) = 1,57

System 3.
70 mm+49 mm width, 34 mm Insulating Strip

U(f) = 2,42 2
Strips with flags

U(f) = 2,13 3
Strips with flags
and low emission foil
U(f) = 1,74 4
Strips with foam

U(f) = 1,81

System 4.
80 mm+49 mm width, 34 mm Insulating Strip

U(f) = 2,69 2
Strips with flags

U(f) = 2,70 3
Strips with flags
and low emission foil
U(f) = 2,02 4
Strips with foam

U(f) = 1,47

Each profile (aluminum frame, thermal insulation profile, sealant) has its tolerances, and the more practically feasible is the manufacturing company, the better is the precision of a profile. When the design engineer creates a new system, he or she focuses on this tolerance and can establish a system with minimal gaps. It's not only the appearance but also performance, as it can provide a tighter fit and guaranteed seal to the glass or in the rabbet ledge zone. The other point is the quality of an assembled structure...

The other point is the quality of an assembled structure...

With foam, we have the decrease of the heat transfer coefficient depending on the size of the profile. Usage of thermal break gives us the inverse proportion because we need a guaranteed flags overlap in the chamber to obtain good performance.

This is not happening in the suggested example because we are limited to only 6 thermal breaks. For section 4 we have too much distance between the noses in the frame profile, which respectively, strongly influences the ratio.

Vincenzo Gargiulo
Co-Founder THERMEVO GmbH

Today thermal insulation is vital for any building, not only for the apartments but also for schools, hospitals, factories... There are many ways to start, but the most important thing is the window and facade - that's where energy loss is crucial, so we need to achieve the best thermal insulation here. New technologies that we have now give us more possibilities. With such materials as foam and reflecting foil, we can gain a lot in the field of building insulation.

Alexander Ebinger
Product Manager THERMEVO GmbH

We expect high demands on the insulation system. We need even more intelligent raw materials and creative natural solutions for our systems. New raw materials should have a good performance in linear expansion and thermal conductivity. And our job is to find the best solutions to the systems, better raw materials to synchronize and bring the systems up.

We assemble profile and foam at the factory; you just have to pick up the ready profile. It saves both money and time and also simplifies logistic of the project.

You might achieve the best results in U(F) value improvement for your project right now. Let us optimise Uf value for you.
Follow us
Get technological and business tips right into your inbox
Made on