The ventilation in a passive house

12 dicembre 2007
The ventilation in a passive house


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One of the salient points of a house is the passive ventilation. Through normal ventilation which can be obtained by opening windows, in a traditional house disperses much heat. On the other hand, for the welfare of the people requires a continuous change of air inside a house. In this case passive obtained through a ventilation system with heat recycling, thus reducing the heat loss by more than 80%.

With a plant ventilation with heat recycling, the fresh air that comes from outside is passed through a heat exchanger, which absorbs heat from the exhaust air and transfers input. The effectiveness of these devices is such that, with an air inlet temperature of 0 ° and a temperature output of 20 °, you can get air to over 16 ° that will bring within the dwelling.

If the incoming air is passed through pipes laid underground at a depth of about 3-4 meters, in the winter you get a further gain some degree, the more important as the more cold outside. When the outside air temperature is -10 ° C, passing through the pipes underground port at about 6 ° C before arriving at the heat exchanger, which can then lead to the air to a temperature of approximately 20 ° C without the need for additional energy sources. 

Ventilation with heat exchanger: the main objections

This system, popular in northern Europe, Italy is still not known. Some argue that the energy absorbed by forced ventilation could jeopardize the energy savings. In fact, with a heat exchanger under house passive, fetches 10 times the energy consumed from. For this purpose, modern plants use single-phase fans similar to those used by personal computers, with an absorption of less than 30 watts.

Of course, to get the maximum performance is important to have the plant as much as possible in the middle of housing, in order to limit the length of piping dell'areazione and then the energy necessary for ventilation.

The advantages of forced ventilation

Another point in favor of plants ventilation with heat exchanger is the welfare inside the house. During the winter because the normal aeration that is done by opening windows is not enough to guarantee the volumes of fresh air needed for a family. Every person in a house needs about 10 m³ of fresh air per hour, but if you add other factors that contribute to spoil the air (such as the kitchen, some appliances ...) they can easily get very values superiors. And without that due intake of fresh air peroxide drops quickly the perception of well-being in the house, and you can even get to weaken the immune system. By employing the ventilation system of a passive house, the air inside is filtered from any heavy pollen or dust, making the environment much more pleasant for those who are allergic.


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