How does it work

The Passive Building works by minimizing heat loss and maximizing the heat gains. To minimize heat losses need first of all a good insulation (about 15 cm +, depending on the position in every part of Greece). Insulation thermal conductivity ≤ 0,1 W / (m K), with the target value U of the shell is between 0,10 and 0,25 W / (m2K).

All windows also have to be very well insulated. It is advisable not to be oversized (cost increases) have "energy glazing with Ug value <0,80 W / (m2K) total Uw value <1.00 W / (m2K). All the frames profile, they satisfy the these specifications can be used.

Then you need to build an airtight barrier inside the insulation layer. The air tightness of the building should not exceed 0.6 air / time changes. This can be made from any material which is and remains airtight. Paper, polyethylene, wood chipboard, plaster etc .. Just do not forget the connections. It should be particularly airtight.

It is obvious that the house should be ventilated. But you have not lost the inner warmth that way in winter. Mechanical ventilation with heat recovery is the solution. It works well only in airtight homes but offering energy recovery up to 90%. In summer the natural ventilation and night use light gaiothermias give the desired thermal comfort.

By minimizing losses maximize heat gain. These come from the sun, to be tucked rich winter at home, but also avoided with proper shading in the summer, and by the activities of users and devices within the home. The building needs a good orientation to the south and good bioclimatic design. Supplementary heating and domestic hot water also originate from the sun or other passive or energy high performance and low-power systems.

End result, the building needs only 15 Kwh / m2 per year for cooling or heating and DHW. Moreover, the energy capital of no more than 120 Kwh / m2 per year.