ENERGY EFFICIENCY PLANS IN SLOVENIA by Nika Jutraž & Slovenian Comenius group Vižmarje Brod Primary School

SITUATION IN SLOVENIA Slovenian government has offered financial assistance (subventions) and co-financing for alternative ways of heating homes, that is, for energy efficient ways of heating. Energy efficient houses are passive houses. Therefore such financial assistance has been offered for constructing such a house. So let us introduce you to our study on passive houses.

WHAT IS A PASSIVE HOUSE? Passive house is energy-efficient construction, it is construction of the future. The concept of the passive house represents the highest energy standards. The passive house and very good low- energy house offer maximum comfort and minimal costs of energy. In economical house the costs of construction are 10 – 15% higher, costs of living are 75 – 80% lower as in usual house. The passive house is well insulated and air-tight building. It is mainly heated by passive solar gain and by internal gains from people, electrical equipment, etc. Energy losses are minimized.

Kinds of energy economic houses USUAL HOUSE (energy consumption is more than 70 kW/m 2 per year) ENERGY STANDARD BUILDING HOUSE ECONOMIC HOUSE LOW-ENERGY HOUSE PASSIVE HOUSE NO-ENERGY HOUSE PLUS ENERGY HOUSE ENERGY INDEPENDENT (SELF-SUFFICIENT) HOUSE

DIFFERENCES BETWEEN USUAL AND ECONOMIC HOUSE Economic houses are carefully designed, well insulated, maximize air- tight, with as few as possible thermal bridges. For heating they use renewable energy from environment. Each "spare", "bio" and "eco" material must be properly installed and it must combine with other materials. The criterion of economy is the annual primary energy consumption per square meter. If usual house uses up to l of oil on square meter annually, then economic house uses up to 3-5 l and passive house less than 1,5 l per year.

DIFFERENCES BETWEEN USUAL AND ECONOMIC HOUSE USUAL HOUSE CONSUMPTION 10 – 25 L OF OIL / m 2 PER YEAR ECONOMIC HOUSE CONSUMPTION 3 – 5 L OF OIL / m 2 PER YEAR THERMAL BRIDGES - balconies insulated badly or uninsulated, connected with construction - formation of thermal bridges - the house has extensions, dormer windows... - balconies hanged, separated from the construction - the house is designed very simple, the outside surface of the walls is as small as possible according to the volume of the interior AIR TIGHTNESS - slots between the bricks are not tight - contact between the wall and windows is bad - windows and front door dont tight - quality realisation of construction provides the required degree of air tight - super-insulated doors and windows

DIFFERENCES BETWEEN USUAL AND ECONOMIC HOUSE THERMAL LOSSES - airing by opening windows, warmth is being lost - insulating envelope of the building is too small - forced ventilation (always fresh air) - insulating envelope of the building is correct, loss of warmth is minimal THERMAL PROFITS - no- the energy of sun is exploited with large windows on southern side and fewer windows on northern side SOURCES OF PRIMARY ENERGY - it uses primary energy (gas, petroleum) - beside electricity it uses renewable sources of energy (sun, air, water, land) WAY OF HEATING - heating with radiators - heating with heat pumps

DIFFERENCES BETWEEN USUAL AND ECONOMIC HOUSE USUAL HOUSEECONOMIC HOUSE cistern for oil/ gasno stove for oil/ gas or solid-fuel stoveheat pump, solar collectors chimneyno radiatorsfloor/ ceiling/ wall heating air conditioningno / cooling through the heating system no ventilation system (use of waste heat)

DIFFERENCES BETWEEN USUAL AND ECONOMIC HOUSE USUAL HOUSEECONOMIC HOUSE usual windowswell insulated windows usual front doorwell insulated front door windows can be anywheremaximum window areas are on southern side, as little as possible on northern side orientation of house is not importantorientation of house to south a thin layer of insulation against the ground, round outside walls and on roof thicker layer of insulation

PASSIVE HOUSE CONCEPTS AND STANDARDS

PASSIVE HOUSE The Passive house is not an energy performance standard, but a concept to achive highest thermal comfort conditions on low total costs. Passive houses do not require active heating system. In winter a comfortable temperature is achieved without a special system for central heating and in summer without air-conditioning systems. Passive house is only low energy building. In passive house we can live as in any normal house. Higher living standards are provided with technical improvements in good thermal insulation and in-house technique. The building is situated of its axis and follows the daily movement of the sun, Heliotrope, Freiburg, Germany

PAS S IV E HOUSE

HEAT LOSSES = HEAT GAINS HEAT RECOVERY OF PASSIVE HOUSE HEAT LOSSES The building is losing heat in two ways: through the envelope, with ventillation (the exchange of air between the building and the surrounding area through the windows and through the gaps). HEAT GAINS Heat gains are very important and they are from various sources: the solar radiation through the windows (so called passive solar energy), the energy of the electricity supply, which is converted into "internal heat sources" in the building. This adds to the heat radiated from persons inside the building.

MAJOR FEATURES OF ARCHITECTURE DESIGN SAVING OF SOLAR ENERGY In the building the heat is stored in order to use it later, when solar irradiation is no available. Because of this the need of heat is reduced. ORIENTATION The correct orientation of the building allows yield of solar radiation. In summer the south facade is shined less than the east and west facade, but in winter the south facade is shined more than east and west facade. South facade is much more suitable for the use of solar energy.

MAJOR FEATURES OF ARCHITECTURE DESIGN FORM OF BUILDING In a passive house it is very important that the external surfaces are in relation to the volume of the building as little as possible. The relationship between surface area and volume is expressed by form factor, which should be close to 1.00, this is when the object is compact and simple. Especially favorable factor has the building with square and round forms.

MAJOR FEATURES OF ARCHITECTURE DESIGN THERMAL INSULATION Thickness of thermal insulation depends on the composition of the wall and is cm. It is very important that thermal-insulative layer goes on continuously all around the house and overlaps frames of windows and doors, which are also the thermal insulation. TECHNOLOGY OF CONSTRUCTION For the construction of passive houses they mainly use solid and lightweight construction. The most widespread method of construction is masiv construction from block of brick, brick block, filled with perlit and block from the light concrete. Outside insulation must be thick enough. The most frequently used material is wood.

EXAMPLES OF ECONOMIC AND PASSIVE HOUSES

SOURCES AND REFERENCES: village/ village/ Delo, annex Delo in dom,