Heating/cooling; zone control and mechanical ventilation

Thanks to the extensive insulation, the simple form factor, the thermal inertia of the ground floor and the air-tight, breathable construction of the outer walls and the roof, little energy is needed to keep this four-façade house at a pleasant temperature inside. During the spring, summer and autumn, the house will mainly heat up with the sunlight. Should there nevertheless be a number of consecutive cold days during these periods, the heat pump will supply the additional heating to maintain the indoor temperature. It’s especially during the cold winter days that this air/air highly efficient heat pump will generate the necessary heat to reach the wanted temperature.

As more and more heat waves occur during the summer, due to the climate change, the built-in thermal inertia within the house (concrete slap, massive walls on the ground floor) will at a certain point no longer be sufficient to keep the house fresh inside. This will be especially the case on the top floor. So an additional air conditioning is required. Due to the fact that the heat pump is reversible, the heating/cooling system can inject cooled air into the different rooms through the same air channels so that the indoor climate remains fresh during the heat waves. Thanks to the highly efficient heat pump and the important insulation, the cost of cold air production is kept limited.

The indoor temperature can be set per zone via the 8 intelligent thermostats. A zone is a group of spaces such as the combination kitchen, dining room, living room and cloakroom or the office together with the waiting room. These intelligent thermostats offer many possibilities to set the right temperature at the right time in the right places.

In addition, the three bathrooms, the dressing room and the laundry room have electric underfloor heating. It’s dimensioned in such a way that it only functions as a complementary heating and only ensures that the floor feels at a pleasant barefoot temperature. The underfloor heating thermostats per room are programmable so that they only heat the floor in the time zones you choose and no unnecessary electrical energy is wasted. These spaces, like all others, are therefore mainly heated by means of warm air injection.

In theory, a window is never opened in a passive home unless it’s for cleaning them. So there is a need for mechanical ventilation. This consists of a balance ventilation type D in which the extracted stale air is crossed via a heat exchanger with the fresh air drawn in from outside, which is therefore preheated before being blown into the various spaces.

The concept used for ventilation/heating/cooling is an integrated 3 channel system where the first two pipe systems are used for the intake and extraction of the outside/inside air needed for ventilation and the third larger diameter channel is used for heating/cooling by means of heat pump outside. Both air flows (fresh air and warm/cold air) are mixed in a distribution unit with motorized flaps per channel that blows the fresh and heated/cooled air into the room.

Such an integrated system is referred to as a ventilation type E. It was developed and produced by a Belgian company, Multicalor. Their Verventa system is a state of the art and relatively unique system and contributes to an energy efficient and comfortable ventilation/heating/cooling system. Less than 500 large houses in Belgium are equipped with this integrated ventilation/heating/cooling system.