Historically, more attention has been given to ventilation, for air quality reasons, than to maximize energy efficiency. For this, the people basically resorted to opening the windows, which in winter were made less time. For a few years now, not only has changed the sensitivity of people in general, but the regulations are increasingly demanding, as we saw with the regulation of radon gas.

One of the best solutions we can opt for, is double flow ventilation systems, with which some studies estimate that it is possible to achieve savings of up to 25% in heating, thanks to the recovery it makes of the air it extracts.


The main feature of these systems is that they have two differentiated fans. On the one hand, a special one for the rooms that register more humidity and, therefore, have the most stale air, such as bathrooms and kitchens. On the other hand, a fan in the driest rooms, as are the rest of the rooms (bedrooms, office, lounge …). The purpose of this system, as dictated by current regulations, is to achieve that the air is renewed, expelling the stale air outside.

Energy efficiency

Why do these systems represent an advance in terms of energy efficiency? Simplifying, because they act as energy exchangers. In other words: if cold air from outside enters in winter, the ventilation unit is able to take advantage of, without mixing, the temperature of the stale air that is expelled from the interior to heat the renewed air that enters. Some calculations estimate that it is possible to recover 80% of the air conditioning energy.

In this same sense to maximize energy efficiency, it is advisable to bet on equipment that has low-consumption motors such as electronic switching.

The importance of filters

It is important to pay attention to the filter system of this equipment, since the quality of the outside air that enters our home will depend on it. In this sense, the first question to answer is what air quality we have in the surroundings of our home. If the quality is good, a conventional filter that retains larger particles, such as grass pollen, may be sufficient.

If on the contrary we live in more polluted regions, it will be advisable to look at filters capable of retaining smaller particles and, thus, enjoy a higher quality air in our house.

On the other hand and entering into maintenance issues, the periodic cleaning of these filters, as well as the air-recuperator and the fans, should not be neglected, otherwise we will not only lose effectiveness, but we could worsen the air quality.

The importance of the professional

If we want to get the most out of a system with these characteristics, we always recommend the advice of a professional. Otherwise we may not notice the importance, for example, of thermally insulating all ducts that cross unheated areas if we do not want to suffer energy losses. The same applies to the installation of the equipment itself, which is always better than avoiding unconditioned areas.

Another advantage of this type of installation compared to other ventilation systems is that you enjoy greater acoustic comfort. The fact that dual flow ventilation systems use their own air intake circuit makes it unnecessary to have to alter the acoustic insulation of the facade.

What can ruin this comfort? Simple, that since it is a mechanical ventilation system, if its design is not correct and appropriate to the specific characteristics of each home, it could become very noisy. Thus, another reason to bet on the help of a professional.