Thermodynamics, architecture and a lot of vision

When talking about optimising the energy consumption of buildings and their contribution to sustainability, thermal insulation is a must. Few needs have been so valued by today’s architects and engineers, both for their economic and environmental implications.

As this awareness has grown in society, companies have realised the enormous importance of assessing how their activities will affect future generations.

That is why, as a company aware of the importance of construction that respects the present and the future, we have faithfully studied different techniques, materials and engineering processes that guarantee maximum thermal insulation, with the greatest durability and minimum social and environmental impact in production. The following three are clear examples of this.

How can we achieve good thermal insulation?

“There is no such thing as cold, it is the universe that steals our heat”. A pretty serious accusation for the cosmos, isn’t it? Well, it’s an absolute truth. According to the second law of thermodynamics, two materials with different temperatures seek to equalize themselves through the principle of entropy. That is, the warmer body passes on thermal energy at least warmly. Are we cold on a rainy and windy January day? No, it’s the air stealing our own body heat.

For centuries we have been concerned with building structures that would defend us from what is outside. Also that would show off our own style, a pleasant view for passers-by. Now it is possible to add to the equation ways of conserving the ambient temperature of the interior, thus increasing its thermal insulation and protection against the heat thief that is the universe itself.

1. Ventilated facade

The ventilated facade is a construction system that has been consolidated with great acceptance among architects and builders, especially for its high quality, aesthetic possibilities and for its undeniable advantages of thermal and acoustic insulation.

In short, this type of facade creates a chimney effect between the insulation and the building envelope. This system does not understand the seasons: in the cold months it maintains the temperature and the internal air conditioning, while in the summer months it isolates the interior from the sun’s rays, keeping the interior much cooler.

A tip we leave you with is that ventilated façade solutions should be considered as alternatives to the Technical Building Code, as they are not included in its basic documents. Therefore, their compliance must be justified by establishing the equivalence of performance to that required by these documents.

The ventilated facade is in first position in terms of thermal insulation, but its importance in the acoustic and aesthetic aspect should not be forgotten.

1.1 Methods for achieving a ventilated facade anchoring solution

There are different solutions for joining the two parts that make up a ventilated facade:
– With mechanical fixing anchorage.
– With fixing anchorage on guides.
– With anchorage on an aluminium structure.
– With chemical fixing anchorage.

Within the latter, there are what are considered to be the most innovative, complete adhesive fixing systems.

The recommended adhesive fixing systems are composed of:
– Elastic adhesive: Ideally, the elastic adhesive should be high-modulus MS-based with high initial grip and vibration damping capacity and should not contain isocyanates.
– Double-sided tape: we recommend that it be made of PE foam and high resistance.
– Primer C-29: primer for the different materials existing in the market: porous and non-porous.

Why is this method so much more efficient than the rest of the solutions? Do they protect the internal heat better, or do they also have benefits that should not be discarded? Let’s see it with a more descriptive example.

1.2 What are the advantages of adhesive fixing on ventilated facades?

We have seen that mechanical fixing methods have advantages and disadvantages like all others. From an aesthetic point of view, we can point out that mechanical fixings tend to leave such a fixation visible, an effect that aesthetically distorts the final image designed by the specifier.

If we carry out a chemical fixing, the aesthetics of the building is maintained in its entirety, no rivets or screws are visible because they are not necessary.

On the other hand, with mechanical fixings there may be noise due to possible gaps in the fixation caused by the wind. The coefficients of expansion of both materials are different, which also causes possible movements.

The chemical adhesives are prepared to absorb movements and vibrations, thanks to their elasticity they reduce the maintenance of these facades, increasing noise protection, resulting in less pollution and significant savings for your pocket

2. Prefabricated concrete facades

This precast concrete solution is one of the most industrialized, so it faithfully meets the requirements that this sector puts among its materials. The potential of concrete in any of its performance aspects, such as mechanical resistance, fire resistance, thermal inertia or acoustic protection, will be reflected in the final result and in the long term.

Prefabricated concrete facades are highly recommended for quick delivery buildings, as their speed of execution, reliability and maintenance make them one of the most efficient models we can find on the market today. Let’s see its advantages in a more exhaustive way.

The precast concrete facades are a fast solution, with great possibilities.

2.1 Why use precast concrete facades?

As concrete is a highly resistant material, it allows the durability of this facade to be greater than that established by regulations, reaching 50 or even 100 years. Moreover, its cycle does not end here, as it has many possibilities for reuse after this period of time.

Its efficiency is twofold: on the one hand, it is energetic because the prefabricated concrete panels provide a usable thermal inertia, reducing air conditioning needs. It is also efficient in the environmental field, since thanks to its carbonation it reabsorbs a significant part of the CO2 emitted during its entire process.

We cannot forget either its great aesthetic capacity: variety of finishes, diverse geometric forms, modulations and colours, among other advantages.

2.2 The importance of sealing in prefabricated concrete facades.

The treatment of the joints in a precast concrete facade is also one of the most important points when we talk about energy savings and sustainability. If we do not treat the joints properly, through these will be produced deterioration in the building as they are areas of passage for water, air, dust, chemicals, etc.

Quilosa’s long lasting sealing systems save energy through the watertight joints of the building’s envelope, reducing the loss of hot or cold air through the permanent connections between the different parts of the building, and also avoiding the tensions between the materials and the passage of deterioration agents.

3. Cold Roofs

One of the main effects of solar radiation is the heating of the surfaces exposed to it. For the building element in question, in this case the roof, the effects can be positive and can be used effectively for example in solar and photovoltaic cells.

But technology must also increasingly deal with the negative effects of solar radiation, especially those resulting from exposure to infrared radiation, which causes the structures of buildings to heat up.

The negative effect of radiation and the consequent overheating of the roof is that its coatings age earlier. The durability of virtually all types of roof coverings in large buildings is determined by their resistance to solar radiation, and their lifetime is about 10 to 15 years at most.

The most innovative building industry uses “Cool Roof” materials for this purpose, and these are parts of sustainable building certification programs such as LEED and BREEAM. This technology studies, improves and applies high Solar Reflectance Index (SRI) materials.

As a curious note, the calculation of the SRI index is done by combining the values of Solar Reflectance (ratio of solar radiation reflected by roof surface) and Thermal Emittance (ability to return the absorbed heat to the atmosphere: this time we do want the universe to steal the heat). The higher the SRI index value, the better the cooling capacity of a roof.

Cold roofs maintain the positive effects of solar radiation, such as energy capture, while keeping building structures at optimum temperature.

3.1 Advantages of cold roofs without loss of efficiency

Among the most effective solutions is the use of highly reflective waterproof membranes. What are the benefits of this product?

To begin with, its protection against extreme temperatures is undeniable. It reduces the temperature of the roof by up to 70%, improving the thermal balance between the interior and exterior of the building. The lower the temperature, the longer the life and the lower the maintenance costs.
Speaking of durability, the coatings of such roofs suffer less as well. But it also improves the performance of solar and photovoltaic panels, as they do not absorb solar radiation for themselves. This gives it the sustainable building certification program we discussed earlier, and increases its market value.

In addition, an important factor in reducing the temperature of the roof is that it makes a structure more efficient. By reducing the investment in air conditioning systems, both in installation and in its operating cost, it reduces CO2 emissions and the cost of building construction. In this way, savings are not only for the pocket, but also for the planet, reducing the “heat island” effect in cities.

Conclusion:

It is clear that thermal insulation brings with it a series of advantages and benefits that are not limited to the temperature of the interior of the buildings. The current materials and techniques that we find in facades and roofs are the best allies to achieve total sustainability, while having an important aesthetic potential.

Any of the three methods responds to a professional demand that seeks a certain quality. In Quilosa we care about offering solutions that meet the demands of the present, but also the future.

Sources:
https://www.impernorasbitra.com/blog/aislamiento-termico
https://www.construction21.org/espana/articles/es/las-grandes-ventajas-del-aislamiento-termico.html
https://cool-r.es/impermeable-revestimiento-cubiertas-coolr/