The Passive House is a standard for energy efficiency in construction, which allows you to economically and environmentally friendly, causing a minimum of harm to the environment, to maintain the comfort of living. Its 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
Energy consumption for heating needs of such a house does not exceed 15 kilowatt-hours per unit area per year. Energy consumption for heating, hot water supply and electricity supply of an energy efficient house does not exceed 120 kilowatt-hours per unit area.
If we compare the energy consumption for heating in Germany, which is regulated by the regulations on thermal protection and energy savings of 2002 (WSchVO and EnEV 2002), there is a direct trend towards a decrease in the need for heating buildings. The recent EnEV Decree regulating thermal protection in Germany set the norm for annual energy consumption for heatingnew and rehabilitated houses from 30 to 70 kilowatt-hours per unit area.
For comparison, in the Russian Federation, the norm of annual energy consumption for heating for Moscow is from 95 to 195 kilowatt-hours per unit area. The actual consumption exceeds these norms many times over.
The benefit of energy efficient homes
Ecohouse has the following advantages:
- Comfort. It is provided by a special engineering system that constantly maintains a pleasant microclimate, cleanliness and freshness of the air. The passive house thus acquires to balance the room temperature.
- Energy saving. If we compare an ordinary building and a passive house, the latter is distinguished by a more than tenfold reduction in heat consumption for heating needs.
- He alth benefits. When the house is passive, throughout the year, all living spaces are constantly supplied with fresh air, there are no drafts, high humidity and no mold.
- Economy. If the house is passive, then the cost of operating its energy supply remains low even as the cost of energy increases.
- Care 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 entry 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 of the windows (up to 2/5 of the facade area) to the south with a tolerance 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 supposed to heat water using a heat pump or solar collector, passive air heating with a ground heat exchanger. In fact, the ideal passive house is a thermos house without heating.
Passive House Technology
How is this result achieved? The passive house standard involves working in five areas:
- Thermal insulation. Insulation of external areas, especially corners, butts, transitions and crossings, should be such that the heat transfer coefficient is less than 0.15 W/m2 K.
- No thermal bridges. It is advisable to avoid inclusions that conduct heat. A special program for calculating the temperature field will allow you to identify and correctly analyze disadvantaged areas of building fencing structures with their subsequent optimization.
- Efficient passive eco-house certified windows. Double-glazed windows filled with inert gas are optimal for such houses. Qualified installation of window structures.
- Mechanical ventilation withheat recovery (not less than 75%) and sealed inner shell. The identification and elimination of leaks is ensured by automated tests on the air permeability of buildings. Comfort ventilation controlled by the user. Ground heat exchanger installation.
Becoming in Russia
In Europe, the building standard of a passive house is widely used, 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 yet, but there are already buildings that are close to this standard. They embody the principles, elements, methods for 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 - no more than 120 kilowatt-hours per unit area;
- Ultra low consumption house - annual heating energy consumption is 16-35, and the total annual energy consumption is less than 180 kilowatt-hours per unit area;
- Low energy house - a building with an annual heating energy consumption of 36-50, and a total annual energy consumption of less than 260 kilowatt-hours per unit area.
Development history
The middle of the 90s of the twentieth century was marked by the foundation in Darmstadt, Germany, of the "Passive House" partnership. Architects Westermauer and Bott-Ridder, under the direction of Wolfgang Feist, designed a four-apartment building, 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 building's annual heating consumption is less than 1 liter of fuel per unit area.
Design Features
The design of the passive house was completed with the following design solutions.
Outer walls made of 175 mm thick silicate bricks are insulated with 275 mm thick polystyrene foam, inside finished with 15 mm thick gypsum plaster and three-layer wallpaper, followed by painting.
Roof covered with humus, filter layer, chipboard 50 mm thick, reinforced with wooden beams, insulated with polyethylene film, insulated with a layer of mineral wool 445 mm thick, finished with plasterboard and three-layer wallpaper, followed by painting.
Basement ceiling, 160 mm reinforced concrete, insulated with 250 mm polystyrene boards, 40 mm soundproofing, 50 mm cement screed and up to 15 mm parquet.
Windows with three panes, double-sided low-e coating, krypton-filled chambers. Wooden frames with polyurethane foam insulation.
Heat recovery implemented by a counterflow heat exchanger in the basement of the house. Electronically switched DC motors were used for the first time.
Hot water supply is provided by flat vacuum collectors with an area of 5.3 square meters. meters per apartment (provide 66% of the need for hot water supply) and compactwall-mounted natural gas condensing boiler. The piping of the DHW system is laid in a heat-insulating layer and is well insulated.
Check measurements
After completion of the 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 set goal.
Annual consumption of thermal energy for heating needs in 1991-1992 was 19.8 kilowatt-hours per unit area, which accounted for 8% of the consumption of conventional housing apartments. In 1992-1993, annual consumption dropped to 11.8 kilowatt-hours per unit area (5.5% of the consumption of flats taken for comparison). Later consumption dropped to less than 10 kilowatt-hours per unit area per year.
The indicators turned out to be so small that experts misinterpreted them for a long time. A significant reduction in energy costs of 90% was achieved through the use of high-efficiency household appliances.
German experience was borrowed by Finnish architects and architects from other European countries. Since that time, 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 have already been built using the basic standards by which passive houses are built. The projects of some of them will be discussed below.
Project in Moscowarea
Among the projects of individual buildings with low energy consumption, one can single out the "Active House" in the Moscow Region, the heat supply of which is also passive.
Active houses are buildings with different levels of energy efficiency, but with greater comfort, achieved through automatic control of the microclimate of the house by the "smart home" system, the use of renewable energy sources and its environmental friendliness.
The project was completed in 2011. It is a structure designed for 5 inhabitants with an area of 229 square meters, two floors, a wooden frame, insulated with ISOVER mineral wool boards, VELUX roof windows, a thickness of external fencing structures of 550–650 mm, a heat transfer resistance of the roof and walls of 12, a floor of 14 (m 2·°C)/Tue. The air exchange rate is 0.4 times per hour. The annual energy consumption for heating alone is 38, and the total 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 needs is an eco-house near Nizhny Novgorod, completed in 2012.
Two-storey building with an area of 141 square meters. meter, designed for four people, is a structure in the form of a wooden frame, insulated with ISOVER mineral wool slabs, with a REHAU GENEO window profile, three glasses, heat transfer resistance of walls 8, 7, roof 12, 8, floor 8, 9 m 2·°C/W. Applied Zehnder ventilation unit with efficiencyrecuperation 84% and air exchange rate 0.3 times per hour. The annual energy consumption for heating is 33 kilowatt-hours per unit area.
Substandard housing is the enemy of energy efficiency
From the very beginning, the idea of a passive eco-house assumed that the cost of such houses would be equal to or slightly more than the cost of ordinary ones. The meaning of the idea was the cheapness of such construction, the optimal ratio of price-quality and quick payback.
The main goal and problem is to equalize the cost of building such structures in the Russian Federation and building ordinary houses. The shift of the energy-efficient home from the elite to the mass sector will not happen quickly. This will require, in addition to the training of architects, also the presence of the necessary skill level of builders, the use of high quality and technological level building materials, equipment and materials with special characteristics.
The mass construction sector in 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 mass housing construction looks unrealistic.
Prospects in Russia
The planned 40% reduction in energy consumption rates by 2020 is intended to turn the tide in favor of energy saving technologies. The rate of resistance to heat transfer will increase from 0.52 to 0.8 m2·°C/W, and then 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. Many dozens of passive houses are expected to be built by 2020. By that time, the necessary conditions will have already been created: banks will develop a system of preferential lending, designers, developers and builders will master new technologies. This will create a market and sustainable consumer demand.
