Types of aluminum windows

Aluminum is one of the most used materials in window profiles. Its great resistance makes it a great option, since it will withstand the weather for many years.

However, it must be detailed that there are several types of aluminum windows. Depending on its construction and the type of opening we will find different characteristics. Let’s see how each type behaves in the face of temperature, air and noise.

Aluminium windows according to profile

Although the material is always aluminum there are two types of profiles: without RPT or with RPT.

We call RPT to the Thermal Break . I leave you this post in which you can learn to see if a window has RPT.

Let’s now look at the two profiles more thoroughly.

Simple aluminium (without RPT)

It is a simpler and cheaper type of profile. It is a window whose structure is made of aluminum and hardly any precautions have been taken to insulate the window thermally and acoustically.

Although its price can be an interesting option, its use is discouraged except for these options:

  • Shutters
  • Rooms without air conditioning (storage room, garage…)

For all other situations it is advisable to opt for a window with RPT. Otherwise the heating cost will be very high.

You can also find these windows under the name of “cold series aluminum windows”.

Aluminium with RPT

It is an evolution that emerged inside aluminum windows. It consists of a profile made of this material but with an inner layer of polyamide that hinders the transmission of heat through the window.

Polyamide is what “breaks” the thermal bridge that occurs when using aluminum. In this way, windows are obtained that better isolate the house from outside temperatures.

As an additional advantage, by using windows with RPT we avoid the appearance of humidity by condensation. The appearance of water on the surface of the window occurs when it is very cold because it does not have the thermal bridge break.

On cold days the temperature of the aluminum window will be practically the same as the outside temperature. This added to the high humidity inside the house causes the appearance of humidity.

Aluminium windows

Aluminum windows according to their opening

In addition to the type of profile we also find differences regarding the type of opening.


This type of frames has a lane through which the window moves to open or close. It is the type of window that was always used in the past.

Even today they are still placed, since it has some advantages:

  • No space needed to open (ideal for small spaces or with furniture)
  • It is the best option to add as a double window

However, it has worse insulation properties and its closures tend to fail more easily.


Casement windows are those that open by rotating on the side frame. They are the most common, and currently it is not uncommon to see a modality of the folding: the osciolabotientes (windows that can also open slightly inwards).

As a general rule, they are more hermetic, offering better thermal and acoustic performances.

Comparison of aluminum windows

It is best to opt for folding aluminum windows with RPT. However, I leave you a small comparison so you can see with data the differences between some windows and others.

Thermal insulation coefficient Wind resistance Sound insulation Safety features
Sliding window / Simple aluminum 3,8 – 4 Class 3 28 dB 2/10 (low)
Casement window / Simple aluminum 3,9 – 4,2 Class 3 33 dB 1/10 (low)
Casement window / Aluminum with RPT 1,5 Class 5 31 dB 3/10 (average)

I remind you that in the coefficient of thermal insulation, the higher the value the worse the insulation of the window. Therefore you should look for profiles with a low coefficient.

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By Catharine Bwana