There are several reasons for building your own home using energy-efficient technologies. The main reason is that with the operation of your home you will incur lower costs. But it is also important that when selling such options will be more attractive to buyers, and the price for it can be set much higher.
In connection with the latest developments in the global energy market, the following conclusion can be drawn. The price for the main source of energy, namely oil, is very unstable and will constantly grow. If you look into the past and analyze the cost of oil, these statements will be confirmed. Therefore, you have to somehow get out, for example, to plan the construction of energy-efficient houses and the purchase of energy-efficient equipment.
Not only material gain is the advantage of this type of house. After all, by reducing energy consumption, we cleanse our atmosphere of harmful impurities and substances that occur during fuel combustion. Most believe that this is an insignificant contribution to the purification of our planet, and the population continues to acquire allergic diseases, as well as diseases of the epidermis and stomach. However, this is not entirely true, only together people can cope with this scourge.
What do we spend energy on in our homes?
If we take an ordinary ordinary house, then we can distinguish several "devourers" of energy:
- various electrical appliances;
- shine;
- heat;
- water heating.
About 72% of all energy is spent on heating our homes. All because before in our country they did not think about saving money and built houses without paying special attention to thermal insulation. In Europe, the situation is not so deplorable, but their indicator also leaves much to be desired - 57%.
We will deal with the concept of energy standards
Energy efficient construction became popular in the nineties. The first interested in this were Germany, France, Sweden and Switzerland. European experts began to associate energy losses with poor thermal insulation of houses, irregular shape of buildings, as well as with the poor location of buildings relative to the cardinal points. The cost of correcting these deficiencies is negligible, so why not save? Then the division of residential buildings into types began:
- Energy efficient home. Such is considered a building that consumes no more than seventy percent of the current from the energy that an ordinary house consumes. In addition, installations using renewable energy sources (windmills, solar panels) and thermal insulation of about fifteen centimeters are used in such structures.
- Low consumption building. Here, the ratio to the consumption of a standard house is no more than forty-five percent, and the insulation is about twenty centimeters.
- Passive construction is considered to be a building with very low consumption - 30% compared to standard houses. Engineers achieve such results thanks to excellent insulation, proper use of heat - natural and that which is ineptly spent in ventilation systems. Typically, such houses are equipped with thermal insulation thirty centimeters thick, an autonomous source of electricity and heat.
- Buildings that do not consume energy. Yes, it is planned to use those, moreover, they will also give electricity to the network. However, so far this is only an experiment. Thermal insulation in such houses is forty centimeters.
Calculation of the required heat
If we take into account that most of the electricity is spent on heat, then the energy standard of the house is selected based on the coefficient E. It indicates the seasonal need for heat - it reflects the amount needed for heating per square meter. Let's analyze what this coefficient depends on:
- The quality of thermal insulation.
- Type of ventilation.
- Orientation of the building to the cardinal points.
- The amount of domestic heat.
It is also worth noting the coefficient of normalized seasonal heat consumption E0. It also determines the required amount of heat for heating a cubic meter, but provided that the structure is erected in compliance with all norms and rules. E0 is calculated as the ratio of the area of the external walls to the heated volume.
How beneficial is an energy-efficient home?
Technologies are improving, and if you look to the future, then we can say: the construction of such houses is economical. Now the investment allocated for the construction of a passive structure is 20 percent more than the cost of building a standard building. After a few years, the difference will decrease by 10 percent. And this can be confirmed by the experience of foreign builders. An energy-efficient apartment building is a good investment option. We confirm this by looking at the following example. As an example, take an ordinary country house with an area of 150 squares, in which one family lives. As a thermal installation in this house, we will choose a gas boiler. Then the cost of operating the home will be as follows:
- heating - 144 kW / m 2 ;
- water heating - 30 kW / m 2 ;
- domestic needs (electrical appliances, cooking, light) - 26 kW / m 2 .
In this case, it turns out that for a year such a house will consume 30,000 kW. If instead of a standard house we take an energy-efficient wooden house, the picture will be as follows:
- heating - 44 kW / m 2 ;
- water heating - 30 kW / m 2 ;
- domestic needs (electrical appliances, cooking, light) - 26 kW / m 2.
An energy-efficient house will consume 15,000 kW per year. Total, you can save on the operation of the house about 50%. Very encouraging information.
Window area
Now, on newly erected buildings, one can often find large glass facades. However, the design of the windows does not allow for thermal protection close to the thermal protection of the main walls. On the other hand, in terms of room lighting, large windows reduce the energy consumption for artificial lighting. We have to look for a middle ground. When designing, the most optimal ratio is 6: 1, where 6 is the floor area, and 1 is the window. For example, take an energy-efficient house and a room of 36 square meters. The optimal glazing area will then be about 6 square meters.
Designing energy-efficient homes. Project Catalogs
Statistics say that in the west, about 80% of private homes are being built on finished projects. Is it possible to build an energy-efficient house on the basis of these options? Projects in large numbers are in special catalogs, and which of the many options to choose?
A very important task is to reduce energy consumption to a minimum. As noted above, the lion's share of it is spent on heating the premises in the winter. However, it should be understood that by increasing the insulation layer, the house cannot be made energy efficient. Here the approach should be comprehensive. It is very important to remove all bridges of cold air, as well as provide for mechanical ventilation.
We pay attention to the walls and the roof
Before acquiring a project, it must be carefully studied to ensure continuous thermal insulation. An energy-efficient house is a building for which the issue of tightness is very important.
Due to this characteristic, cold air will not enter the room. Everything should be airtight, from the doors to the roof. The walls of such houses are plastered with a double layer, and the roof is made with thermal insulation and vapor barrier. The joints and fastenings are closed with special adhesive tape.
Energy efficiency calculation
As noted above, a building is considered to be energy efficient, consuming no more than seventy percent of the electric energy of the amount that an ordinary house consumes. Consider the coefficient E and its value:
- For an ordinary house, the coefficient. E is less than or equal to 110 kW / m 2 .
- For an energy-efficient home E is less than or equal to 70 kW / m 2 .
- For a passive house E is less than or equal to 15 kW / m 2 .
In the West, a more modern way is considered to calculate the energy efficiency of buildings by the coefficient . It indicates the amount of energy required for heating, ventilation, water heating, lighting and air conditioning. Consider the classification of buildings, depending on Ep:
- For passive constructions Ep is less than or equal to 0.25.
- For economical buildings, it is less than or equal to 0.5.
- For energy-saving buildings Ep is less than or equal to 0.75.
- For ordinary buildings, it is less than or equal to 1.
- For passive constructions Ep is less than or equal to 0.25.
- For the most energy-consuming buildings, Ep is more than 1.5.
The issue of ventilation and heating
We have already said that an energy-efficient house should be equipped with mechanical ventilation, with the function of generating heat. Therefore, choosing a project, you need to make sure that such ventilation is provided in the house. This is important because conventional ventilation will not function in an airtight house. It is also worth noting that gravity ventilation works well at temperatures just above zero, so in the summer it is almost useless.
In airtight, energy-efficient homes, mechanical ventilation is best shown to allow heat to be extracted from the exhaust air. Such ventilation will allow you to do without the usual water heating system in the house, which will lead to savings on radiators, pipes and heating installations. Therefore, be careful when choosing an energy-efficient home: projects should include this type of ventilation.
Some subtleties of construction
Let's analyze the subtleties of the construction of such structures. If you plan to build an energy-efficient home with your own hands, you need to know the exact number of people who will live there. After all, people themselves create household heat - when washing, cooking, using electrical appliances. It turns out that too large houses will not be considered energy efficient, provided that several people live in them. Also, you should carefully consider the effective current consumption, choosing energy-efficient instruments and equipment. It will be useful to equip the house area according to the cardinal points and climatic conditions in your area.
Conclusion
The design and construction of energy-efficient houses in the future will be almost the only direction in the construction industry. Therefore, you need to think about it right now.