Eco house is a concept of ecological and biopositive home with low energy consumption. It relies on the concept of a Passive House originally developed in Germany. Demands of such house are typically below 15 kWh/m2 a year, which is 1/7 part of a common house’s energy consumption. Thanks to reduced heat losses and optimized energy supply it is possible to achieve 90% saving on heating in comparison with a usual house.
Such an attractive economy is achievable thanks to using of heat insulating panels 40 to 50 cm thick, ensuring heat transmission coefficient no higher than 0.25 W/(m2K). Windows consist of triple insulating glass units. Air tightness is one of the major factors which ensure energy efficiency. Therefore a controlled ventilation system in habitable space becomes a strict necessity. A heat exchanger is integrated into a ventilation system to ensure recuperation of heat. In summer a ventilation system works inversely and cools the incoming air. This effect may be enhanced by installing a heat exchanger which uses temperature difference between air and ground to obtain energy. Besides, it is becomes common to actively use solar energy for heating, how water supply and power generation. Normally an Eco house should not require a large-scale heating system – heating is required only in a couple of the coldest months and is provided by a small-scale system.
Another key to energy efficiency is correct location and orientation of a house. Ideally it should be protected from cold northern winds by features of a landscape. Windows in a northern wall should be small to avoid heat losses, sometimes northern windows are even dispensed with. In turn, southern windows have large area and can ensure positive energy balance if well-insulated.
The most advanced Eco houses can incorporate aspects of an Active house (Energy-plus house) – with an extraordinary qualitative insulation and active using of renewable energy systems it can cover the whole demands in energy and even feed the surplus power to the grid.
But an Ecohouse is not only about saving energy and money. Environment and health are another important aspects incorporated into the concept. An Eco house is built of materials which are natural, 100% renewable and do not have any negative impact on the environment. It is also obvious that living in an Ecohouse should be good for health. A good example of a suitable material is straw panels.