Controlled mechanical ventilation system with high efficiency domestic heat recovery

Air quality, and therefore its temperature, humidity and purity are key components for the climatic comfort inside a building. Especially in winter, when the opening of windows for air exchange results in significant heat loss, an integrated ventilation system is the best solution to maintain both levels of thermal performance of the building and indoor air quality. The recent legislation on energy saving in buildings and new technological achievements in the field of thermal insulation and sealing of windows and doors, if on one side have made modern homes more comfortable in terms of heat and sound, on the other, have transformed in real sealed environments, with the risk of turning them into “harmful traps” for the domestic production of pollution. The basic principle is to make the building more than just well insulated, but also hermetic to air. At this point, to realize the necessary air change, always needed to ensure a good quality of the room atmosphere, you must use a mechanical ventilation system. The renewal of air in the environments is essential for proper sanitation and housing, even the European Directive 2002/91/EC of the European Parliament and Council of 16 December 2002 on the Energy Performance of Buildings cited the “need” of fans standard buildings. This “need” collides with the shared worldwide need, to improve the energy performance of buildings in order to limit consumption. Controlled mechanical ventilation with heat recovery DRU series therefore is an ideal solution for reducing the energy requirements of buildings and at the same time improves the indoor environmental qualiy and health. 


The air is canalized by a double pipeline distribution system, divided between fresh air drawn from outside (supply) and polluted air drawn from moist rooms and the kitchen (return). The pressure required to move air is supplied from the fans in the heat recovery unit. The two air streams are filtered and then sent to a cross flow recovery unit, in which, through the metal surfaces with good thermal conductivity, the outgoing air disposes part of its heat (or extracts a part) to the outdoor renewal air. The air thus treated, after being further filtered, is sent in the environment through the channels connected to appropriate diffusers.


1. Energy saving on the total needs for air heating of the renewal air.

2. Achieve better air quality due to the continuous and gradual input of fresh air, taken from an area with a minimum of pollutants and filtered before being sent in the rooms.

3. Preserve the house from the attack of mould and moisture.

4. Maintaining an elevated acoustic comfort, because it is not necessary with controlled mechanical ventilation, to open windows for air exchange. Particularly important in areas of high noise, close to busy roads or railway.

5. Contribution to the diminishing of environmental pollution

Reduced energy consumption

About 70% of energy consumption in developed countries is due to the costs for heating. Both in winter and summer, however much energy is lost with natural al ventilation, especially when the windows are opened or tilted. Heat loss through windows can be up to 50% of total heat loss of a building and for this reason it is very advantageous to use a mechanical ventilation system which not only provides the necessary ventilation but allows also more than 90% of heat recovery. This means an important economical saving on energetics costs.

Advantages for the health

The only effect of opening the windows, besides being difficult to calculate the quantity of air renewal necessary, constitutes a huge waste in terms of energy and therefore money and allows many pollutants and allergens to penetrate easily into our homes. Recent researches have also underlined that the concentration of many pollutants inside the house can be two to five times higher than outside and as the highest exposure to pollutants occurs within our own homes. One has to consider that the western population spends, on average, 90% of their time in indoor environments, and most of this time inside their homes. In 1984 the World Health Organization pointed out the need to fight the symptoms of Sick Building Syndrome by energy effective solutions to achieve air renewal. It is clear that a proper ventilation system is essential to ensure good quality of air, with benefits for health and welfare, preventing headaches, allergies, fatigue and sickness.

Property value

Today, the moment they are placed in real estate, buildings shall be equipped with an energy performance certificate. With this document the purchasers and renters of properties will have an objective and transparent information on the characteristics and the energy costs of the building. Such buildings are more efficient in terms of energy and consequently have a lower cost of operation, thus they are more attractive for the housing market and will see increased their commercial value. Considering also that the price of oil and gas, the fuel most commonly used for heating, will continue to rise in the future, it becomes clear how the value of a building equipped with heat recovery and therefore low energy consumption will grow together with the cost of sources used to heat it. The value of the building will consequently be, not only preserved, but even increased.

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