Best windows: Aluminum or PVC?

23 jun 2022Back
Qual a melhor janela? Alumínio ou PVC 0

Aluminum has proven to be better in the most important aspects:

  • Energy efficiency;
  • Medium and long term price;
  • Security (toxic gasses, fire and theft);
  • Sustainable (aluminum is 100% recyclable without ever losing its initial properties);
  • Durability;
  • Versatility.

Energy saving is influenced by many factors.

There is a tendency to emphasize that the aluminum frame of a window (frames) is disadvantageous for transmitting more cold or heat, and for this reason when choosing a frame it is believed that a non-metallic frame would increase the savings. However, it has been proven that aluminum frames achieve the same energy performance as a PVC window, in similar products.


The elements that influence the energy performance of the windows are: glass, the existence of thermal break in the profiles, accessories (sealants, foams, among others), state of conservation, and not least, the functional and ergonomic design of the window itself and the respective opening typology. .


1 - Is it possible to save by replacing old windows with new ones?

Yes. First of all, before changing windows, you should pay attention to the area in which the house is located. In hot areas it is possible to save about 16% of energy and in cold areas, at least 18%.


The most important elements of a window that influence energy savings in a hot area are:

  • solar factor of glass (64%);
  • thermal transmission of glass (22%);
  • air infiltrations (13%);
  • frame transmission (1%).


The most important elements in a window introduced in a building located in cold areas are:

  • thermal transmission of glass (62%);
  • air infiltrations (27%);
  • frame transmission (7%);
  • frame/glass ratio (4%).

Replace your aluminum windows with RPT (breaking the thermal bridge) because in the short term you will achieve energy savings practically equal to that obtained by a PVC one. In the medium and long term, aluminum retains its qualities intact. Thus, the durability of this material allows aluminum windows not to deform and produce air infiltrations, which impairs the energy performance of the windows.

In the long run, an aluminum window is more economical. Why?

As aluminum windows are more durable, it is natural that in the long term they become more economical. Because aluminum is resistant, windows made with this material do not need to be reinforced over time, as is the case with PVC windows. Proof of this is the emblematic Empire building State Building , in New York, built in 1930/1931, whose windows are made of aluminum and have remained intact.


window strength

PVC is a plastic, so its resistance is quite limited. Over time, it needs structural reinforcement on the inside, usually steel, to keep it from bending.

  • Aluminum very resistant to deformation: Young's modulus = 700,000 kg/cm2
  • PVC easily deformable: Young's modulus = 25,000 kg/cm2



A sustainable product or material is one that lasts. While aluminum comes from bauxite, one of the most abundant elements on our planet, which is why it is 100% sustainable, PVC comes from oil, which is not at all sustainable, and its reserves are estimated to run out in no longer than 50 years.



Aluminum is 100% recyclable, infinitely recyclable, and retains its properties unchanged.

On the contrary, PVC cannot be recycled infinitely nor its qualities remain intact, so PVC windows do not come from a 100% recycled product, as established by the European profile standard EN 12608. This standard excludes any type of PVC recycled on the outer surface of the profiles. PVC is practically not recycled.



Thanks to their hardness and resistance, aluminum windows offer greater security against intrusion.

In addition, a study carried out at the GAIKER technological center, in case of fire, aluminum does not produce any of the toxic substances that PVC emits ( chlorobenzene , benzene, ethanol, ethylene, formaldehyde, ethane, methane, hydrochloric acid and sulfur dioxide) .

  • PVC - The smoke emission is considerable (VOF4* = 1886)
  • Aluminum - Aluminum does not emit smoke (VOF4* = 1)

* VOF4 - Capacity value after 4 minutes of testing



Another of the characteristics in which aluminum is superior to PVC is its versatility. Aluminum allows you to make all kinds of shapes, it can be molded until you adopt the desired design.

It also allows for a wide range of finishes, applied for metal protection and decoration purposes, using lacquering and anodizing treatments. In both cases, it is recommended that they be carried out under the guidelines of the Qualanod (anodizing) and Qualicoat (lacquering) quality brands. We emphasize that we have been certified by these two entities for several years. ( extrusal certifications )


Source: information based on a study carried out by Tecnalia / Cidemco denominated "determination of the importance of the factors of influence of a window in the energy demand of a building". APAL

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