Slovenčina (Slovenská republika)English (United Kingdom)


Low-energy houses

Houses can be classified according to the total energy consumption for heating. House can be divided on ordinary, low-energy and passive, while the energy consumption is measured in kWh/m2 for a certain time unit. For comparison, the total energy consumption per year for old house is 150-250 kWh/m2, for new buildings 80-120 kWh/m2, for low-energy house is 50 kWh/m2, for passive house less than 15 kWh/m2 and for zero house less than 5 kWh/m2.

Low-energy house concept is based on the energy consumption of heating. Energy consumption of low-energy house should have half energy consumption compare to new buildings. Low-energy house should have build from materials which suit thermal technical requirements for low energy houses. The house should therefore be thermally insulated as possible. Opening structures should be as little as possible.

The windows are very important role in this type of home. They transmit light to the interior of the house, and significantly contribute to saving heating energy. Particular attention should be given to the window frame, which is necessary to insulate well. Window glazing system is multiple. The most commonly used insulating is triple glazing, filled with argon or krypton.
During the construction of low-energy building is possible to use different types of wooden structures, sandwich panels or masonry systems. Wooden structures are accessible and less time consuming and there for is wood the most used material. A construction made from wood have an optimum indoor humidity and adequate vapor permeable of exterior walls.

Envelope requires proper insulation. In present, particularly popular are becoming materials based on natural ingredients, for example straw or sheep's wool. Conventional insulating materials are mineral wool or polystyrene. Insulation thickness is determined individually, depending on the composition of insulated walls and thermal insulation properties of the material.
However, quality insulation requires exterior walls, but floor and roof as well. The roof should be insulated even slightly better than the exterior walls. It is more affected by heat leaks. Consumption of low-energy house is not depend only materials used in its construction, but the subsequent technological devices as well. This can include properly designed heating system (floor heating, radiators or convectors), or the use of heat pumps. A building can use control ventilation with heat recuperation.

Recovery or heat recovery is a process during which the building supply air is preheated by heat extracted from the exhaust air. Warm air is discharged without benefits through the open window, but in the heat exchanger transmit most of its heat incoming air. The air passes through the filter, which rid him of dust, pollen and other pollutants. Efficiency of heat exchangers can be up to 90%.

Passive houses
House with annual energy consumption under 15 kWh/m2 refers to as a passive house. Compared with conventional house consumes approximately ten times less of heating energy. The design of this house is difficult to project and to construct. It is necessary to keep some important principles during making a project of pasive house. E.g. compact shape without unnecessary protrusions (building shape factor i i.e. the ratio between heated area of envelope to heated volume of a building), glazed surfaces facing south (heat obtain from sunlight), superior thermal insulation (significantly greater thickness thermal insulation) and high equipped windows (triple insulation stuffed with inert gases), consistent solution of thermal bridges (elimination of thermal bridges). Standard heating system may be completely missing. In this type of house is sufficient to cover the heat losses of passive energy resources, and the heat emitted by people, appliances, sunlight falling through the windows, the heat from the exhaust air and etc. It does not count with uncontrolled ventilation. Passive houses extensively using ventilation with heat recovery. If necessary, the ventilation system can be mounted radiator, which heat indoor air.