Passive house , energy-saving house or eco -house ( German Passivhaus , English passive house ) is a structure whose main feature is low energy consumption due to the use of passive energy - saving methods. [1] A passive house consumes an average of approximately 10% of the specific energy per unit area consumed by most traditional buildings.
In the context of rising prices for electricity and heat, there is an urgent issue of operating costs for housing. An indicator of the energy efficiency of an object is the loss of thermal energy per square meter (kW · h / m²) per year or during the heating period . On average, an ordinary building in Germany consumes 100-120 kWh / m². An energy-saving building is considered to be a building where this indicator is below 40 kWh / m². For passive houses, this figure is even lower - about 10 kWh / m².
Achieved by reducing energy consumption primarily by reducing heat loss of the building.
The architectural concept of a passive house is based on the principles of compactness, high-quality and effective insulation, the absence of cold bridges in materials and junctions, the correct geometry of the building, zoning, and orientation to the cardinal points. Of the active methods in a passive house, the use of a ventilation system with recovery is mandatory.
Ideally, a passive house should be an independent power system that does not require any costs to maintain a comfortable temperature. Heating a passive house should be due to the heat generated by people living in it and household appliances. If necessary, additional "active" heating, it is desirable to use alternative energy sources . Hot water can also be provided through renewable energy installations: heat pumps or solar water heaters . To solve the problem of cooling / conditioning the building is also supposed to be due to the appropriate architectural solution, and if necessary, additional cooling - due to alternative energy sources , for example, a geothermal heat pump .
Sometimes the definition of “passive house” is confused with the system of “ smart house ”, one of the tasks of which is to ensure control of the building’s energy consumption. The “ active home ” system is also different, which, in addition to spending little energy, also generates so much of it that it can not only provide for itself, but can also be transferred to the central network (a house with a positive energy balance).
History
Energy Saving Building Development
The development of energy-saving buildings dates back to the historical culture of the northern and Siberian peoples, who sought to build their homes in such a way that they effectively retain heat and consume less resources. Material- and energy-saving round shape of dwellings ( plague , yurt , etc.), as well as a shell made of effective heat-insulating materials (animal skins, felt ) are prototypes of the technology of a passive house. A classic example of a home energy-saving technique is the Russian stove , which has thick walls that retain heat well and is equipped with a chimney with a revolving system.
The modern experiments to increase the energy saving of buildings include a structure built in 1972 in the city of Manchester in the state of New Hampshire ( USA ). It had a cubic shape, which ensured a minimal surface of the external walls, the glazing area did not exceed 10%, which made it possible to reduce heat loss due to the space-planning solution. There was no glazing along the northern facade. The flat roof was covered in bright colors, which reduced its heating and, accordingly, reduced ventilation requirements in the warm season. Solar collectors were installed on the roof of the building.
In 1973 - 1979, the ECONO-HOUSE complex was built in the city of Otaniemi , Finland . In the building, in addition to a complex space-planning solution, taking into account the peculiarities of location and climate, a special ventilation system was used , in which the air was heated due to solar radiation , the heat of which was accumulated by special double-glazed windows and shutters. Also, solar collectors and a geothermal installation were included in the general heat exchange scheme of the building, providing energy saving. The shape of the slopes of the roof of the building took into account the breadth of the construction site and the angles of incidence of sunlight at different times of the year.
Passive House
An interesting scheme for equipping a passive house was proposed in May 1988 by Dr. Wolfgang Feist, founder of the Passive House Institute in Darmstadt ( Germany ), and Professor Boo Adamson from Lund University ( Sweden ). The concept was developed in numerous research projects funded by the state of Hesse , Germany .
In 1996, the “Passive House Institute” was established in Darmstadt .
Design
The concepts of “green” and “passive house” are often mixed, and a passive and eco-friendly house often means houses built from traditional natural materials or recycled waste - aerated concrete , wood, stone, brick , although stone houses are cold, and some modern heaters are not natural materials. Recently, passive houses have often been built from inorganic waste products - concrete , glass and metal. In Germany , special plants have been built to process such waste into building materials for energy-efficient buildings.
Thermal insulation
Enclosing structures (walls, windows, roofs, floors) of standard houses have a rather large heat transfer coefficient. This leads to significant losses: for example, the heat loss of an ordinary brick building is 250-350 kW · h with 1 m² of heated area per year.
The technology of a passive house provides for effective thermal insulation of all enclosing surfaces - not only walls, but also the floor, ceiling, attic, basement and foundation. In a passive house, a highly effective external thermal insulation of enclosing surfaces is formed. Internal thermal insulation is undesirable since it reduces the thermal inertia of the rooms and can lead to significant intraday temperature fluctuations, for example, when solar heat enters through the windows. From the point of view of thermal physics, it is also most effective to apply thermal insulation from the outside, since in this case the supporting structures are always in the zone of positive temperatures and optimal humidity, which takes the dew point beyond. Also, the elimination of "cold bridges" in the enclosing structures is carried out. As a result, in passive houses, heat losses through the enclosing surfaces do not exceed 15 kWh per year per 1 m² of heated area - almost 20 times lower than in ordinary buildings.
Windows
Heat losses through the windows are divided into radiation (radiation in the infrared range from the house to the outside), convection (gas in the inter-school gap) and heat transfer (gas, glass and binding) heat transfer. Radiation accounts for two-thirds of the heat loss, the rest is for convection and thermal conductivity. The passive house uses advanced energy-efficient windows. Sealed double-glazed windows, 1-chamber (two glasses) or 2-chamber (three glasses), are filled with low-temperature argon or krypton with a warm distance frame (polymer or plastic instead of metal, which is a cold bridge). One of the glass panes on the inside is covered with a selective coating (I-glass or K-glass) reducing radiation loss. Warmer multi-chamber profiles are used for making binding. Also, in some cases, glasses are tempered in order to avoid destruction during heat shock. Sometimes, for additional thermal insulation, shutters, shutters or blinds are installed on the windows.
Installing a roller shutter (roller shutter) allows you to increase the thermal resistance of the window block by 20-30% (the heat transfer resistance of the roller shutter structure can be 0.18 - 0.27 m 2 K / W).
The largest windows face south (in the northern hemisphere) and bring on average more heat in winter than they lose. Orientation of windows to the east and west is minimized to reduce energy costs for air conditioning in the summer.
Climate control
Today, the technology of building passive houses does not always allow abandoning active heating or cooling, especially in regions with constantly high or low temperatures, or sudden changes in temperature, for example, in areas with a continental climate . However, the organic part of the passive house is the heating, air conditioning and ventilation system, which consumes resources more efficiently than in ordinary houses.
Ventilation
In ordinary houses, ventilation is carried out due to the natural stimulation of air movement, which usually enters the room through special grooves (sometimes through window ventilators - ventilation valves) in the windows and is removed by passive ventilation systems located in kitchens and bathrooms.
In energy-efficient buildings, a more complex system is used: instead of windows with open slots, soundproofing sealed double-glazed windows are used, and the supply and exhaust ventilation of the premises is carried out centrally through a heat recovery unit. An additional increase in energy efficiency can be achieved if air leaves the house and enters it through an underground air duct equipped with a heat exchanger . In the heat exchanger, heated air transfers heat to the cold air.
In winter, cold air enters the underground air duct, heating there due to the heat of the earth, and then enters the recuperator . In the recuperator, the exhausted domestic air heats the incoming fresh air and is thrown out into the street. The heated fresh air entering the house results in a temperature of about 17 ° C.
In summer, hot air entering the underground air duct is cooled there from contact with the ground to about the same temperature. Due to such a system in a passive house comfortable conditions are constantly maintained. Only sometimes it is necessary to use low-power heaters or air conditioners ( heat pump ) for minimum temperature control.
Lighting
LED blocks can be used.
Cost
Currently, the cost of building an energy-efficient house is approximately 8-10% higher than the average for a conventional building. Additional construction costs pay off within 7-10 years. At the same time, there is no need to lay water heating pipes inside the building, build boiler rooms, fuel storage tanks, etc.
Standards
In Europe, the following classification of buildings depends on their level of energy consumption:
- "Old building" (buildings built before the 1970s) - they require about three hundred kilowatt-hours per square meter per year for their heating: 300 kWh / m² year.
- "New building" (which were built from the 1970s to 2000) - no more than 150 kWh / m² year.
- “House of low energy consumption” (since 2002 construction of houses of a lower standard has not been allowed in Europe) - no more than 60 kWh / m² year.
- "Passive house" - no more than 15 kWh / m² year.
- “Zero-energy house” (a building that architecturally has the same standard as a passive house, but is engineered in such a way as to consume only the energy that it produces) - 0 kWh / m² year.
- “House plus energy” or “active house” (a building that, using the engineering equipment installed on it: solar panels, collectors, heat pumps, recuperators, ground heat exchangers, etc., would generate more energy than it consumed).
The Energy Performance of Buildings Directive, adopted by the EU countries in December 2009 , requires that all new buildings be close to energy neutrality by 2020 . [2]
In the USA, the standard requires energy consumption for heating a house no more than 1 BTU per square foot of space.
In the UK, a passive house should consume 77% less energy than an ordinary house.
Since 2007, every home sold in England and Wales must receive an energy efficiency rating. A Certificate of Energy Efficiency will be a mandatory part of the House Information Package. Each house for sale will be inspected by an independent inspector who will determine the house’s efficiency rating in terms of energy consumption and CO 2 emissions.
In Ireland, a passive house should consume 85% less energy than a standard house, and emit CO 2 94% less than an ordinary house.
Since March 2007, new houses in Spain should be equipped with solar water heaters to independently provide from 30% to 70% of the demand for hot water, depending on the location of the house and the expected water consumption. Non-residential buildings (shopping centers, hospitals, etc.) must have photovoltaic equipment [3] .
In Russia, there are also a number of documents (decrees, recommendations, decrees, standards, territorial norms) regulating the energy consumption of buildings and structures. For example, BCH 52-86, which determines the calculation and requirements for a hot water system using solar energy.
Distribution
By 2006, more than 6,000 passive houses, office buildings, shops, schools, kindergartens have been built around the world. Most of them are in Europe .
In a number of European countries ( Denmark , Germany , Finland , etc.), special targeted state programs have been developed to bring all regular development objects to a conditionally passive level (ultra-low consumption houses - up to 30 kWh / m³ per year).
In CIS countries
In Russia, the energy consumption in homes is 400–600 kWh / year per square meter. This figure is supposed to be reduced by 2020 by 45%.
Several have already been built in Moscow [ how much? ] experimental buildings using passive house technology (residential building in Nikulino-2 ). The hot water supply system of this house uses the heat of the soil and exhaust gases, which reduces the consumption of thermal energy by 32% [1] . The demonstration project of such a house is also built near St. Petersburg . The construction of the first village of passive houses near St. Petersburg has begun.
In Nizhny Novgorod, a demonstration passive house was built using solar collectors , a heat pump , vertical wind generators , an air exchange system with recovery .
In Ukraine, the first passive house was built in 2008. [4] Today [ specify ] 3 more passive private residential buildings are being built in different cities of Ukraine.
Since 2010, the experimental construction of low-rise energy-efficient houses for the resettlement of dilapidated and emergency housing has been financed by the Housing and Utilities Fund . At the beginning of 2011, several energy-efficient buildings with the participation of the Fund have already been built in different regions of Russia.
The first certified passive house was built in Russia in 2011 by the Mosstroy-31 company according to the project of Thomas Knecht. The specific consumption of thermal energy for heating is 24 kWh / m² year. [five]
Ecology
An average Canadian cottage produces 5-7 tons of greenhouse gases annually. US homes annually produce about 278 million tons of greenhouse gases. Passive houses can significantly reduce these emissions .
Passive house building technologies can significantly reduce energy consumption. For example, in the 1990s in Germany, energy consumption in housing and communal services decreased by 3%. And UK households consume about 30% of the country's total energy.
See also
- Light well
- Green building
- Stable city
- Low energy house
- Earthship
Notes
- ↑ 1 2 Resin V.I. Effective energy-saving management methods in construction // Moscow Architecture and Construction. 2003.Vol. 508-509. No. 2-3. S. 7-13.
- ↑ Solar PV Could Be Standard in New European Buildings by 2020
- ↑ Spain requires new buildings use solar power
- ↑ “Passive House in Kiev” in the database of the Institute of the Passive House in Darmstadt
- ↑ Alexey Schukin. From the house-thermos to the house-concept . "Expert" No. 13 (796) (April 02, 2012). Date of treatment November 2, 2012. Archived November 5, 2012.
Literature
- Gabriel I., Ladener H. Reconstruction of buildings according to energy-efficient house standards = Vom Altbau zum Niedrigenergie und Passivhaus. - S .: BHV-Petersburg , 2011 .-- S. 478. - ISBN 978-5-9775-0574-1 .