Energy saving policies are gaining ground and becoming increasingly demanding. The Passive Building (PC) therefore comes to combine energy efficiency, comfort and economy, while giving architectural freedom. It is a model building, which offers at the same time high energy efficiency, comfort, economy and is environmentally friendly. PK is not a brand, but a design philosophy that is open to all and this has been proven in practice. Therefore, it is more than "just" an energy efficient building.
What is a Passive Building? (PK)
PK (Passiv Haus in German and Passive House in English) is a building in which the internal thermal comfort (ISO 7730) is ensured exclusively by preheating or pre-cooling the amount of fresh air required (DIN 1946) for the correct indoor atmosphere. , without the use of additional air recirculation.
PK maintains a comfortable and pleasant temperature all year round with minimal energy requirements. Buildings are heated passively, ie they make efficient use of the sun, indoor heat sources and heat recovery, with the result that conventional heating systems are not necessary even on the coldest days of winter.
PKs maintain, regardless of the climate or the area, a pleasant atmosphere with minimal energy requirements. Through the excellent quality and technology materials, the correct design guarantees ideal temperatures for the whole year. They heat passively, making use of solar energy, with the result that conventional heating systems are not necessary even on the coldest days & nights of winter. In summer, again using passive cooling techniques, such as proper shading design, manages to keep the building cool.
To achieve a proper design, PK must follow 5 basic principles:
High level of thermal insulation
Properly designed, insulated and installed frames
Design without thermal bridges
Airtightness of building shell
Ventilation system with maximum efficiency in energy recovery
How PK works
PK operates by minimizing heat loss and maximizing thermal gains. In order to minimize heat losses, good insulation is needed first of all (approximately 15 cm +, depending on the location in each part of Greece). Insulation with thermal conductivity. 0.1 W / m²K, with the aim of the UT value being between 0.10 and 0.25 W / m²K.
All windows must also be very well insulated. It would be good not to be oversized (increase in cost), to have "energy" glazing with value Ug <0.80 W / m /K total value Uw <1.00 W / m²K. All window profiles, provided they meet these specifications, can be used.
Differences between conventional and PK
Passive Building is more than just saving energy.
In terms of indoor atmosphere, PKs are unbeatable and the differences are large compared to a conventional building. To see the differences in real conditions we quote the following example where measurements were made in a PK in Papagou and a conventional building in Paros.
In Paros with an outside temperature of 9o C and 58% relative humidity we have 16.9o C inside the house (three degrees below the minimum thermal comfort limit) and 71% relative humidity (with 8-hour dehumidifier operation). The CO2 concentration is high and the heating systems (electric radiator and gas stove) burn non-stop.
Unlike in Papagou PK at the same time, with lower outside temperature and much higher relative relative humidity, the conditions are simply ideal. Inside the house we have 21.9o C and relative humidity 39% with minimal to no use of heating.
In conclusion, PK is the future in a global environment that has made energy saving issues a necessity. The aluminum industry is already ready for this new reality in terms of building design and already offers top solutions that meet the strict specifications of PK.
Republication:
Aluminum magazine, issue February 2020
Sources:
Hellenic Institute of Passive Building (EIPAK)
Passive House Institute (PHI)