Passive house is a standard of energy efficiency in construction, which allows economically and environmentally friendly, causing a minimum of environmental damage, maintain a comfortable stay. His consumption of thermal energy is so small that either there is no need to install a separate heating system, or its power and size are small.
Energy efficiency standard
The energy consumption for the heating needs of such a house per year does not exceed 15 kilowatt hours per unit area. Energy consumption for heating, hot water and electricity of an energy-efficient house does not exceed 120 kilowatt-hours per unit area.
If we compare the indicators of energy consumption for heating in Germany, which are regulated by the regulations on thermal protection and energy saving in 2002 (WSchVO and EnEV 2002), then there is a direct tendency to decrease it for the needs of heating buildings. A recent EnEV decree regulating thermal protection in the Federal Republic of Germany sets the annual energy consumption for heating new and sanitized houses from 30 to 70 kilowatt-hours per unit area.
For comparison, the Russian Federation has established the norm of annual energy consumption for heating for Moscow from 95 to 195 kilowatt-hours per unit area. Actual consumption is many times higher than these norms.
The advantage of energy-efficient homes
Ecohouse has the following advantages:
- Comfort It is provided by a special engineering system that constantly maintains a pleasant microclimate, purity and freshness of air. At the same time, a passive house acquires a balance of room temperature.
- Energy saving. If we compare an ordinary building and a passive house, the latter is distinguished by more than tenfold reduction in heat consumption for heating needs.
- Health benefits. When the house is passive, throughout the year all living quarters are constantly supplied with fresh air, there are no drafts, high humidity and there is no mold.
- Profitability. If the house is passive, then the cost of operating its energy supply remains at a low level even with an increase in the cost of energy.
- Caring for the environment. When the house is passive, the use of energy-efficient technologies increases the level of environmental protection.
Energy balance
One of the characteristics of an energy-efficient home is the energy balance between ventilation or transmission heat loss and its intake with solar energy, internal heat sources and heating. For balance, such components as optimal thermal insulation of the heated volume, compactness of the building, passive use of heat from solar radiation by orienting most windows (up to 2/5 of the facade area) to the south with an allowable deviation of 30 ° and due to the absence of shading are extremely important. It will also be useful to use household appliances with a high level of energy efficiency. It is also assumed that water is heated using a heat pump or solar collector, passive air heating with a soil heat exchanger. In fact, an ideal passive house is a thermos house without heating.
Passive house: technology
How is such a result achieved? The standard of a passive house involves work in five directions:
- Thermal insulation. The insulation of external sections, especially angular, butt and transition joints and intersections should be such that the heat transfer coefficient is less than 0.15 W / m 2 · K.
- Lack of thermal bridges. It is advisable to avoid inclusions that conduct heat. A special program for calculating the temperature field will allow to identify and competently analyze the disadvantaged places of the building fencing structures with their subsequent optimization.
- Passive eco-certified certified efficient windows. Double low-emission double-glazed windows filled with inert gas are optimal for such houses. Qualified installation of window structures.
- Mechanical ventilation with heat recovery (at least 75%) and a sealed inner shell. Identification and elimination of leakage points is ensured by automated tests of the breathability of buildings. Comfortable ventilation controlled by the user. Installation of an earth heat exchanger.
Formation in Russia
In Europe, the construction standard of a passive house is used in large quantities, and in the Russian Federation, the design and construction of energy-saving buildings is only in its infancy.
There are no houses that meet the requirements of the energy efficiency standard, but there are already buildings close to this standard. They embody the principles, elements, methods of calculating an energy-efficient home.
Also, in relation to the Russian Federation, a classification of buildings by energy efficiency has been created:
- passive house - heating consumes less than 15, total energy consumption per year - not more than 120 kilowatt hours per unit area;
- a house with ultra-low consumption - the annual energy consumption for heating needs is 16–35, and the total energy consumption per year is less than 180 kilowatt-hours per unit area;
- a house with low energy consumption - a building with an annual energy consumption for heating purposes - 36-50, and a total annual energy consumption - less than 260 kilowatt hours per unit area.
History of development
The mid 90-ies of the twentieth century was marked by the founding in Darmstadt, Germany, the partnership "Passive House". Architects Westermauer and Bott-Ridder, under the leadership of Wolfgang Feist, designed a four-apartment house, the prototype of which was all subsequent energy-saving houses. The passive house was built in 1991 with the participation of the government of Hesse. The annual consumption of the building for heating needs is less than 1 liter of fuel per unit area.
Design features
The design of the passive house ended with the following design solutions.
The outer walls of silicate brick 175 mm thick are insulated with a layer of expanded polystyrene 275 mm thick, inside they are finished with gypsum plaster 15 mm thick and three-layer wallpaper with subsequent painting.
The roof is covered with humus, a filtering layer, chipboard 50 mm thick, reinforced with wooden beams, insulated with polyethylene film, insulated with 445 mm thick mineral wool, trimmed with drywall and three-layer wallpaper, followed by painting.
Basement slab, 160 mm reinforced concrete, insulated with 250 mm polystyrene foam slabs, 40 mm sound insulation, 50 mm cement screed and up to 15 mm parquet.
Windows with three glasses, double-sided low-emission coating, krypton-filled cameras. Wooden frames with polyurethane foam thermal insulation.
Heat recovery is implemented by a counterflow heat exchanger in the basement of the house. For the first time, DC motors with electronic switching were used.
Hot water supply is provided by flat vacuum collectors with an area of 5.3 square meters. meters per apartment (provide 66% of the needs of hot water) and a compact wall-mounted condensing boiler for natural gas. The pipelines of the DHW system are laid in a heat-insulating layer and are well insulated.
Control measurements
Upon completion of construction and commissioning of the building, control measurements of air flow, pressure test, round-the-clock measurements of temperature and energy consumption were made. They confirmed the achievement of the goal.
The annual consumption of thermal energy for heating in 1991-1992 was equal to 19.8 kilowatt-hours per unit area, which amounted to 8% of the consumption of apartments of ordinary housing. In 1992-1993, annual consumption decreased to 11.8 kilowatt-hours per unit area (5.5% of the consumption of apartments taken for comparison). Later, consumption fell to less than 10 kilowatt-hours per unit area per year.
The indicators turned out to be so small that specialists misinterpreted them for a long time. A significant reduction in energy costs, amounting to 90%, was achieved through the use of highly efficient household appliances.
The German experience was borrowed by Finnish architects and architects from other European countries. Since then, more than 40 thousand passive eco-houses have been built in the world.
Passive house: construction in Russia
In the Russian Federation, in Moscow, St. Petersburg, Nizhny Novgorod and Yekaterinburg, several objects are being implemented or already built using the basic standards by which passive houses are built. Projects of some of them will be considered later.
Project in the Moscow region
Among the projects of individual buildings with low energy consumption, one can single out the Active House in the Moscow Region, whose heat supply is also passive.
Active houses are a building with different levels of energy efficiency, but with great comfort achieved by automatically controlling the microclimate of the house with the Smart Home system, using renewable energy sources and its environmental cleanliness.
The project was completed in 2011. It is a building for 5 residents with an area of 229 square meters, two floors, a wooden frame, insulated with ISOVER mineral wool slabs, VELUX roof windows, 550–650 mm thick external fencing structures, heat transfer resistance of the roof and walls 12, floor 14 (m2 ° C) / W The air exchange rate is 0.4 times per hour. Energy consumption for heating alone per year is 38, and the entire energy consumption is 110 kilowatt-hours per unit area per year.
Project in Nizhny Novgorod
Another example of a project with ultra-low heat consumption for heating is an eco house near Nizhny Novgorod, completed in 2012.
A two-story building with an area of 141 square meters. the meter, designed for four people, is a wooden frame structure, insulated with ISOVER mineral wool slabs, with REHAU GENEO window profile, three panes, heat transfer resistance of walls 8.7, roof 12.8, floor 8.9 m 2 ° C / W. A Zehnder ventilation unit was used with a recovery efficiency of 84% and a ventilation rate of 0.3 times per hour. The annual energy consumption for heating is 33 kilowatt hours per unit area.
Low-quality housing is the enemy of energy efficiency
From the very beginning, the idea of a passive eco-house suggested that the cost of such houses would be equal to or slightly more expensive than ordinary ones. The idea was based on the cheapness of such construction, the optimal price-quality ratio and quick payback.
The main goal and problem is to equalize the cost of building such structures in the Russian Federation and the construction of ordinary houses. The shift of an energy-efficient home from an elite to a mass sector will not happen quickly. This will require, in addition to the training of architects, also the necessary level of qualification of builders, the use of high-quality building materials and technological level, equipment and materials with special characteristics.
The mass construction sector of Russia prefers to reduce the cost of housing through the use of low-quality building materials and the exploitation of low-skilled labor. As long as such preferences remain, the transition to high-tech energy-efficient construction of mass housing looks unrealistic.
Prospects in Russia
The planned reduction in energy consumption by 40% by 2020 is designed to turn the tide in favor of energy-saving technologies. The rate of heat transfer resistance will increase from 0.52 to 0.8 m 2 · ° C / W, and after that to 1.0. The use of recuperation in ventilation systems will be mandatory. At this time, it is important to adapt and implement foreign experience. By 2020, the construction of many dozens of passive houses is expected. By that time, the necessary conditions will have already been created: banks will develop a system of soft loans, designers, developers and builders will master new technologies. This will create a market and steady consumer demand.