Inspiring examples from Slovenia
Single family house in Ig - QNH/Au (PHPP'07) = 14 kWh/m2/year
At first plus energy house for a top gymnast Mitja Petkovšek was barely a vision. But as a result of hard work plus energy house with enhanced living comfort, positive environmental and economic impacts became a reality.
Mitja Petkovšek, house owner, said: “Seeing how much I have been enjoying in my plus energy house since I moved in, the decision to build a house with a very low energy demand was certainly correct. Before I moved in with my wife Mojca, I had been hearing a lot of misconceptions about living in an active house, but life is perfectly normal, only more comfortable, cheaper and more pleasant. Automatic ventilation is a wonderful thing since we don’t have to think anymore when we the windows should be opened. Our guests are always impressed about the quality of the air in the house. The costs for heating are negligible (50 to 60 € annually), since potential of solar and internal heat gains is fully exploited. When the sun is shining on a freezing winter day, the need for heating reduces drastically and even when you are standing close to the window, you would never guess how freezing it is outside, since the surface temperature of the window is extremely high. I am glad that I have worked with people that I trust and that the same people have lived up to their promise about building and living in the plus energy house.”
Single family house in Medvode - QNH/Au (PHPP'07) = 14 kWh/m2/year
|Photos: Lara Romih|
Active house Lumar is specific for maximum utilization of renewable energy sources, resulting in a minimal carbon emissions and therefore lower impact on the environment. Emphasis is placed on the exploitation of solar energy, which is used for several purposes, such as passive heating through the large glass surfaces, which are shaded by an electronic controlled system in the summer as part of the intelligent system installations. This system was patented by a Slovenian manufacturer and enables activation of the biggest consumers of electricity in time of lower tariff, which significantly optimizes the operating costs of the highest consuming appliances. Electricity is produced by photovoltaic solar panels that are mounted on the roof.
The entire energy need for space and domestic hot water heating is covered with a heat pump and solar collectors. Share of electricity produced by PV on annual basis is larger than total energy needed for functionality of the household.
Multi-dwelling building in Ljubljana - QNH/Au (PHPP'07) = 15 kWh/m2/year
Housing Fund of the Municipality of Ljubljana offers these dwellings with minimal space standards as a temporal solution to citizens with housing problems. Building was built in compliance with Passive House standards, as it also fulfils the main criterion of annual heat demand per treated floor area according to PHPP methodology: QNH/Au (PHPP'07) < 15kWh/(m2*a). Blower door test resulted in 0,30h-1 hourly air change rate at 50 Pascal pressure difference (n50).
Electric heaters (400W) are installed above windows, where inlets for air supply are located. Ventilation system is central with soil heat exchanger and a high level of heat recovery. Building has roof-mounted PV installation with a peak capacity of 14kWp.
Kindergarten in Preddvor - QNH/Au (PHPP'07) = 25 kWh/m2/year
Kindergarten in Preddvor, built in 2012, is located in west part of the country (Municipality of Preddvor). Architects have designed this 1347m² floor area kindergarten with the idea of Passive House standards thus achieving low primary energy demand 61kWh/(m²a).
Kindergarten is constructed as lightweight prefabricated timber building. Opaque outer parts are extremely well thermally insulated. External windows and doors have average U-value below 0,90W/m2K. Average thermal conductivity of building envelope, thermal bridges are included, is 0,11W/m2K. Airtightness test showed an amazing achievement in the range of large timber buildings with n50 < 0,2h-1. This result is three times lower as required according to Eko sklad standards (financial fund for state subsidies).
Ventilation system with heat recovery (on average more than 80%) ensures permanent air quality, which creates better working conditions, and greater concentration of children and success of employees at work. Optimized building envelope at the same time also results in higher perceived thermal comfort.
Kindergarten is heated from an existing modern biomass boiler, which is located in the adjacent building. PV modules are mounted on the roof; solar power plant operates at 96,7kWp.
Kindergarten in Moravče - QNH/Au (PHPP'07) = 15 kWh/m2/year
At the start of the project brick construction was chosen but economic analyses showed that timber low energy solution is more cost effective. Kindergarten was designed with integrated design approach. That is way an idea to integrate biomass district heating power plant to the kindergarten was elaborated. Plant is located in the basement and kindergarten in ground floor and first floor. Combining district heating plant along with the one in kindergarten allowed to lower costs of project. Kindergarten successfully applied for states subsidies that promote energy efficiency and power plant was awarded with EU funds. Biomass power plant now distributes energy to 6 public (high school, kindergarten, hospital, library, cultural building) and 11 private buildings. Heating device with the power of 1MW will be upgraded to 2MW when and if it will be needed.
Kindergarten has windows orientated towards south and is extremely well thermally insulated. Architectural design is compact with heat recovery ventilation system.