We live in an era of change. This sentence in the form of warnings, owned by Confucius, reflects the precariousness of the current world. We adapt, adapt, tighten their belts. Including due to another rise in price of electricity, gas. The houses in which we live more and more expensive to contain. Often we hear shouting about energy efficiency and savings.
Meanwhile, the world has long been thought out and everything worked out, ready to take Yes Use the experience and technology. There are several concepts of property as minimum energy consumption and give it to external customers: passive house, zero house, active house-energy house. In short, it is considered to be a passive house, energy consumption for heating which is, according to regional standards, no more than 10-15 kWh / m² per year. Zero is home consumption and production of energy from renewable sources that is equally. Well, he will be active house that produces more energy from renewable sources than it consumes, and gives over, for example, in a common network. It is easy to notice that zero and can be active at any house, when you install it in the respective power of wind turbines, solar panels or biogas plant. That is the fundamental difference – substantial additional costs on the cost of the house on the energy-saving equipment. Another matter was originally designed and built passive house, designed for many years of operation, that is, at a minimum additional cost, may be zero, and in a little more – active. The concept of the passive house suggests that it is relatively inexpensive construction such housing can cost as much as a normal home, or slightly more expensive. The difference in cost should be quickly recouped through lower operating costs.
Thus, the passive house. It is a building with an extremely minimized heat loss, optimally oriented to the cardinal points, blend in with the surrounding landscape. Ideally, the passive house is to be an independent power system does not require the cost of maintaining a comfortable temperature. All the necessary energy for the life of the people to be generated inside the house. As an example, if you dress accordingly, you can feel very comfortable even in cold weather – the clothes, in fact, insulation keeps the heat of our body. That’s a passive house must be a sort of “termorubashkoy” keep warm, do not miss any heat or cold. This is achieved by excellent thermal insulation, tightness, heat recovery ventilation in the house with the influx of fresh air, energy-efficient appliances. In theory, everything is simple, but in practice the concept of the passive house requires a review of some of the traditional construction technologies. The figure below shows the basic heat loss of an ordinary house.
As you can see, the actual reduction in heat loss requires the solution of a whole set of necessary tasks – thermal insulation of walls, roof and foundation, construction of windows and heating systems hot. Also required is almost complete tightness of the building and the presence of mechanical ventilation with heat recovery.
The concept of the passive house.
Thus, the concept of energy-efficient homes suggests the following:
– The correct orientation of the building on the side of light, openness and lack of shading the south facade, windscreen north side of the building dull green spaces, trees, other buildings households. purpose;
– Maximum compactness of the building – the ratio of the area enclosing structures – walls, windows, roofs, floors and the total volume of the building (its usable area). The smaller the area enclosing structures with respect to the usable area of the building, so it is compact;
– Possibly a complete absence of balconies and other external elements. The ideal is considered the maximum proximity of the building to form a hemisphere facing cut on the ground;
– The location to the south of the maximum number of windows, translucent structures that have passed deep into the building low rays of the winter sun, but not more than 40% of the wall area;
– Availability of outdoor summer sun protection in the form of bay windows, cornices, terraces, shading translucent structures, windows and exposed beams give the high summer sun into the building;
– Optimal location and value of windows and other glass constructions shall be as follows: 70-80% on the south side, 20-30% of the east, to the west of 0-10%
– The lack of windows on the north side, the light transmitting structures through which heat would leave the building;
– Separation of buffer and living areas; arrangement of auxiliary premises in the north as buffer zones; Location residential area in the south-east;
– The presence of massive storage element indoors – walls of solid brick or concrete, decorated inside, for example, clay plaster, for receiving, storing and giving them energy in places where direct sunlight from the low winter sun;
– Capture the energy storage element of internal heat sources – household appliances, computers, lighting, body, etc .;
– Complete insulation of the entire perimeter of the building: foundation, walls, roof; that is, the creation of external thermal insulation of the building envelope – heat conductivity of solid walling (foundation, walls, roof) in a passive house must not exceed 0,15Vt / m? x C ?. The thermal conductivity of windows and other glass constructions should not exceed 0,85Vt m? X C ?;
– Internal insulation of all external walling – foundation, walls, roof;
– The maximum possible leaks (air-tightness) of the outer shell of the building; – The system of ventilation with heat recovery;
– Use of underground channels (ground heat exchangers) for passive pre-heating (or cooling) air and water.
Using the above method allows energy-efficient house is very good to keep warm in winter when the heating system emergency shutdown temperature inside of the house is reduced only by 1-2 ° C in the day.
What methods addresses the problem? For example, the correct orientation of the building depends on the terrain, seasonal winds, the presence or the planned planting of green spaces and trees. The requirement for openness of the southern facade is the key to enter the solar energy involves sufficient space from that direction. Securing the northern part of the building is also not unimportant – the better covered the northern side of the building, the less the loss will be in this direction. The winning look in this respect at home on the southern slopes of the hills, as well as at home, covered the north are not residential buildings, garden, forest planting.
Although the optimum form at the maximum and minimum screen area will hemisphere shape passive building can vary significantly, depending on the needs and goals. To this effect area under the house, the area of its southern facade, architectural solutions, floors, as well as other requirements, in particular, the availability of outdoor summer sun protection.
So actually the approximate solution to the hemisphere can be seen very rarely, in pilot projects. The most commonly used form of the house, in the context of the north-south resembles an irregular polygon, with a large south facade and a smaller area of the north side. In terms of passive house can be as polygonal, in the south-east and south-west facade, but the most popular is the plan with the extension of west-east axis. Above the windows, translucent structures of the southern facade elements must be positioned outdoor shading – terraces, canopies, awnings, preventing the penetration of solar radiation in the accommodation during the summer, and vice versa, allowing the low winter sun to warm the room as much as possible.
The internal layout of the passive house is subject to all the same problem of minimizing heat the living area and the maximum amount of solar heat into it. To solve the northern part of the house is usually not a residential premises – bathrooms and toilets, kitchen, pantry. Housing – bedrooms, children’s rooms, living rooms – Located in the south-eastern, southern parts of the house. Passive houses often have open floor plans (flowing space) to facilitate the thermosyphon effect in moving the solar heat from the south façade through the house. For the distribution of warm air in buildings with closed ventilation plan is used.
A special place is given to energy-saving house using solar heat. To rays penetrate freely inside during the cold season, the area of the glazing can be up to 40% of the southern facade. To keep the sun’s heat inside the walls of residential premises located opposite the windows, making thermal storage and is made of high-density material: concrete, brick, stone, adobe. These materials, due to the effect of thermal inertia – the ability to absorb energy and release it after some time, may store thermal energy for its subsequent slow recoil reducing temperature fluctuations in the building.
Thus, a significant part of the heating load of the building can bear the sun energiya.Glavnym way to prevent losses in the passive house is the insulation. At the same time, a clear division of building materials in the construction. Construction and fasteners must provide durability, insulation must provide thermal insulation, decorative materials – appearance. With this approach it is possible to reduce the number of cold bridges, by which heat can escape from the house to the outside. The house is formed by several layers of insulation – internal and external.
For external wall insulation system applies external insulation of the building. This ventilated curtain walls and facade insulation system with plaster layer. In addition, the used insulating panel thickness 25 – 40 cm. Insulation should be continuous, without holes. For example, do not have a balcony directly dock with protecting designs – walls, ceilings, and separated from them and placed in the thermal insulation of external oporah.Vnutrennyaya insulation is often performed in a single unit with a vapor barrier to preserve the full integrity of the building, as well as with internal decorative coating, including environmentally friendly materials.
Thermal insulation of the roof is also important, and solutions are similar to the thermal insulation of the walls. In passive houses since the first projects is widespread pent roof, which is easier to insulate, although there are complex polygonal structure.
Thermal insulation of the roof – a multi-layered system, which includes both the actual insulation to prevent the formation of cold bridges and vapor barrier, enabling ventilated wooden roof elements, as well as preventing the formation of condensation, reducing the effectiveness of the insulation properties of the insulation. In addition to a fully insulated roofs, cold roofs meet when insulated top floor and the roof itself is a separate element of the design of the house.
The base of the house – the foundation – also completely Insulate with simultaneous waterproofing. We solve this by the following measures: insulation of the foundation from the outside along the entire height; Set horizontal exterior insulation around the perimeter of the house at the lower edge of the support of the foundation; installation of foundation blocks on a sandy base; of the scheme of the first floor slab laying on the ground through the sandwich: sand cushion insulation, thick insulation; as foundation blocks above the surface shall be thermally insulated from the outside and the inside. In this scheme, the zone of soil freezing will be at a considerable distance from the house and heat loss through the cellar to be insignificant. Similarly solved the problem of reducing heat loss in the regeneration of the underground facilities. In addition to insulation of the foundation also is taking steps to insulation overlap.
Much attention is paid to the passive houses the glazing and windows. In the windows of the houses are used for sealed glazing, at least two strip between the frame and sash. Moreover, these windows must be equipped with a low-emissive glazing coated, filled with an inert gas such as argon. The frames are made of a profile with a filling with a minimum heat transfer coefficient, as well as wood. Most windows do not open, or opens only for ventilation. Sometimes, additional thermal insulation, shutters on the windows installed, blinds or curtains. To prevent cold bridges window installation shall be in the plane of the insulation. Therefore it is necessary to pay special attention to proper installation of window designs, for example, to ensure thorough incorporation into the insulating layer, controlling the tight and snug
Another source of heat is the front door. Therefore, at the entrance to the house should be energoseregayuschy heat vestibule and a second door. Requirements for sealing closed the door and door frame joint with structural elements of the building are the same as for windows.
All seams of the roof, walls and foundation are trying to make a passive house with termovkladok of structural materials with low thermal conductivity. For example, cellular concrete blocks, special types of bricks, etc. Places additionally sealed joints various types of sealants, plastic mortar.
Incidentally, a illustrative example of Scandinavia, Sweden when passive houses effective insulation thickness of the walls is obtained at least 400 mm in the roof – not less than 500 mm, lower span – not less than 300 mm.
In principle, using modern insulating materials, the rate of energy consumption for heating can be reduced less than the norm, but the calculations of the Institute of Passive Houses have demonstrated that it is at 15 kW is achieved extremum mathematically in terms of “the effect / cost.” If you try to reduce to zero the cost of heat, dramatically increasing construction costs and the complexity of the system.
One of the most important passive house engineering systems, can significantly reduce heat loss, a ventilation system with heat recovery air – supply and exhaust ventilation ducts must pass through a heat exchanger where the heat of the exhaust, but the heated air is transferred to the fresh, but the cold air from the street. Just supply channel for air intake can be laid under the ground, below the frost to further warm up (or cool in summer) air. But for quite a cold climate application of such a heat exchanger is doubtful, because there is a real risk of condensation and freezing of moisture in it at low temperatures.
Eventually recovery system allows you to return to the premises up to 90% of the heat of the outgoing air.
Improving energy efficiency at home using alternative sources.
To further increase the energy efficiency of a passive house is used a number of engineering solutions aimed at both the external energy consumption savings – solar systems and heat pumps as well as the production of electricity – solar kits.
Solar collectors, allowing maximum use of solar radiation to heat water, provide passive house with hot water in the spring and summer, as well as can maintain a low temperature heating system – floor heating, warm walls. Heat pump highly efficient use of the potential of the environment – air, earth, water, allowing to get the output is several times more heat energy than electricity consumed. In a passive house, thanks to its minimal heat losses, the heat pump will work only on the coldest days of the year, and its maximum capacity is achieved when working with low-grade heating – fan coil units, the same warm floors, heated walls. Solar panels and wind generators, converting solar radiation into electricity and wind power, lead to the passive house zero. And if their performance is higher than the energy consumption of a passive house, then active at much lower than installed capacity, and therefore the cost of the system than it would take an ordinary house.
The use of systems such as solar collectors, heat pumps, heat recovery air leads to the abandonment of traditional methods of heating – radiators, batteries, boilers, fireplaces, wood stoves with their low efficiency. But even in this modern accommodation, as it is the passive house, often using additional furnace plant fuel.
The best – a slow-burning wood stoves with catalytic afterburning of combustible gases. Sami oven with catalytic afterburning or pyrolysis boilers have a very high efficiency of about 80%. Low heat loss eco allow the use of such low-power boilers, and wood is a renewable source of energy.
In addition to direct heating of the house there is a seasonal accumulation of heat from solar radiation. The function of conversion of solar energy into heat is solar collectors and accumulators are the gravel poured into special containers, the soil under the house, large containers of liquid. These heat accumulators are used to increase the thermal inertia of the house. Also advantageous and convenient when heat accumulators serve as a constructive element of the house, with its own design simple and inexpensive device. Due to the thermal conductivity of these batteries rapidly lose energy, so their arrangement requires a good thermal and waterproofing, but allows maximum use of solar energy throughout the year, garnering the summer and spending the winter. There are also hybrid heat pump – geliokollektornye setting summer sun warms the soil through underground probes and heating period to select its heat, thereby significantly increasing the COP of the heat pump.
So, in addition to the maximum energy saving passive house requires minimal costs for heating and hot water supply, as well as that is not unimportant, to create a comfortable interior environment, because people on average more than 60% of his time just at home. Creating a comfortable environment – is, as mentioned above, the use of low-temperature heating systems – a warm walls, floors, giving the effect of heat in the winter sunlight, use Coatings of natural materials – clay plaster, stone, wood, linoleum and wood chips from linseed oil . All together to create a comfortable, eco-friendly environment at the same time having a minimal negative impact on the environment. En stability in an era of change.