Heat Recovery Ventilation System (or HRV) represents an increasingly widespread plant solution within modern buildings. There are many reasons for this: from the ever-increasing focus on indoor air quality and the building's energy profile, to the simple need to monitor and control the presence of pollutants in the air.

This naturally also applies to building renovation: contemporary renovation makes the building an airtight envelope in order to avoid any energy dispersion.

Of course, there are consequences to be considered, because this way, potentially harmful substances or pollutants are bound to remain in rooms that are so perfectly insulated. And leaving aside for a moment carbon dioxide, formaldehyde, radon gas and other agents that may prove hazardous to health, one must not make the mistake of underestimating an apparently trivial presence, but one that is widespread in almost any environment: humidity.

Why is it so important?

Humidity is determined by the amount of water vapour contained in a mass of air. Its presence and concentration largely result from everyday activities: just think that just one person's stay in a closed room produces about 40-50 grams of water vapour in an hour. Or that every time we cook, we generate almost one kg of steam per hour of boiling time. And a single shower can produce almost twice as much.

It is very easy, therefore, to reach very significant humidity levels in any enclosed space, unless proper air exchange is provided. And high humidity concentrations have various undesirable effects, not only for people, but for the building itself.

Condensation, for example, is a direct consequence of humidity. And as we all know, it is often the main factor in the appearance of mould on walls and ceilings. But moisture can also infiltrate the interior of structures, significantly affecting thermal transmittance characteristics and negatively affecting the building's energy performance.

But the most obvious consequence of high humidity concentrations is reflected in the perception of temperature, and thus in comfort. At a temperature of 30°C and a humidity level of 50%, the perceived temperature rises to 36°C. At 80% humidity it goes up to 43°C!

For this reason, the greatest attention must be paid to solutions for controlling humidity levels when designing a building.

Installation solutions

The provision of water-fed dehumidifiers, or by means of an internal refrigeration circuit, is the first element to manage fluctuations in indoor humidity. This solution is also absolutely indicated in the presence of underfloor cooling systems, not only for a question of comfort, but to avoid any condensation on floor surfaces.

The most complete solution, however, remains the provision of a controlled mechanical ventilation system with dehumidification treatment. In this way, a single system takes care of both renewing the air in the room and dehumidifying it when necessary.

Our solutions are Maxima, Isothermal and Hydronic.

All models - available in both horizontal ceiling-mounted and vertical thermal unit versions with different air flow rates - combine air exchange, filtration and thermal energy recovery with dehumidification treatment (and for some models both summer and winter thermal integration is available).

In the Isoterma and Maxima models, the units are equipped with a refrigeration circuit with a compressor, which starts the dehumidification treatment when required by the connected humidity probes. The Isoterma model is designed for isothermal dehumidification: i.e. it injects air into the environment at the same temperature as the air already present.

In the Maxima model, on the other hand, the dehumidification process can take place in two modes: isothermal, as just described, or with thermal integration. In the second mode, if it is necessary to reduce the internal temperature indicated as the comfort temperature, the unit (after having dehumidified the air) will feed it into the room at a lower temperature, to reduce the inertia of the cooling system and reach the desired comfort conditions more quickly.

The Hydronic model, finally, is distinguished by the adoption of a hydronic battery that, supplied with water between 7 and 10°C, dehumidifies the air.

All the models mentioned operate dehumidification with partial recirculation of the internal air. In this way, the humidity reduction process is faster and comfort conditions are preserved.