How difficult is it to optimize energy consumption for heating? Indeed, in the end, it is its consumption that determines the total efficiency of the entire system. To do this, you need to know the correct costs for heating a house with electricity and gas, the calculation largely depends on the degree of thermal insulation of the house.
Calculation of heat losses at home
What is the peculiarity of any heating system? Its work is designed to maintain a comfortable temperature in the room by compensating for the heat losses of the building. They will largely determine the future costs of heating a country house.
To calculate this parameter, you need to know the value of the heat transfer resistance coefficient R (m² * C / W) for each type of material from which the building is built. It is the reciprocal of the thermal conductivity λ- W / m * C. Calculated by the following formula, where d - wall thickness:
R = d / λ
The value of the thermal conductivity of building materials can be taken from the data in the figure.
Such a technique is based precisely on these data and gives an answer to the question: what costs for heating a frame house will be in the future during its operation. It is important to consider all types of materials: load-bearing walls, window structures and thermal insulation.
The next step is to calculate the area of external walls and windows. Suppose that in a house of 160 m², built of two-row bricks and an outer layer of 100 mm expanded polystyrene insulation, the total wall area is 360 m². The remaining 103 m² is occupied by window constructions with R = 1.2. In this case, the average heat loss per 1 m² with a decrease in temperature by 1 ° С will be:
- 1 / (0.47 + 1.86) = 0.43 W / m2 * C - for walls;
- 1 / 1.2 = 0.83 W / m2 * С - for windows.
Based on this, it will be possible to find out what costs for heating with an electric boiler are necessary to obtain the optimal amount of thermal energy. To do this, we will take as a basis the value of the optimal temperature in the room + 25 ° С, and outdoors - 15 ° С. The difference between them will be 40 ° С. In this case, the total heat losses of the house will be equal:
0.43 * 320 * 40 + 0.83 * 106 * 40 = 5504 + 3519 = 9023 W or 9.023 kWh
The same principle is used to calculate the heat loss through the attic and the floor. In this case, they will be approximately equal to 3.92 kWh for the floor and 1.83 kWh for the attic. The total value for the entire building will be:
9.023 + 3.92 + 1.83 = 14.773 kWh
A correction factor must be added to the resulting figure. It is due to the fact that the cost of heating with electricity or gas will increase during the opening of the entrance doors, ventilation, etc. It is best to multiply the heat loss value by 1.1. Thus, it is possible to increase the power reserve of the heating system to 14.773 * 1.1 = 16 kW / h.
To accurately calculate the cost of gas or electric heating, you can calculate the heat loss using online calculators. It is necessary to choose those versions that take into account not only the parameters of the walls, but also the floor with the ceiling.
Calculation of costs for an electric boiler
The most expensive type of energy carrier is electricity. Therefore, the calculation of heating costs for boilers of this type requires a balanced and accurate approach. Having chosen the optimal power of the equipment, it is necessary to correctly distribute it throughout all rooms. Ideally, it is recommended to calculate heat losses for each room.In this case, the accuracy of the calculations increases significantly.
The correct calculation of electricity costs for heating should be carried out taking into account the following factors:
- Various types of tariff accounting. Currently there are 3 of them: one, two and multi-tariff;
- Installed thermostats on radiators, connected to temperature sensors;
- Possibility of manual and automatic regulation of the boiler power.
As can be seen from the data in the table, to minimize the cost of heating a country house, it is best to activate the system at night. However, in fact, to maintain a comfortable temperature, it must work during the day. In addition, you need to install a two-rate meter, which is fraught with certain difficulties - high cost, paperwork during registration.
The optimal distribution of the heating system is as follows:
- 60% to 80% - night functioning;
- FROM 20% to 40% - daily.
Such a scheme is relevant if there are no tenants in the house during the day. The operating time of the system is 16 hours a day, which is quite enough to maintain a comfortable temperature. We take into account that a boiler with a thermal power of 16 kW and an actual consumption of 16.7 kW was chosen. This indicator directly depends on the efficiency. Then the estimated costs of electric heating for the calculated house will be:
16.7 * 1.63 * 16 * 0.7 + 16.7 * 4.79 * 16 * 0.3 = 437 + 383 = 820 rubles / day
Taking into account the constantly increasing tariffs for electricity, it is necessary to envisage saving methods. For example, most of the cost of heating a frame house will be reduced due to good wall insulation and the use of wood as the main building material. An important factor is the availability of an auxiliary system. These include solar panels, wind turbines that generate electricity, or a geothermal heating line. In this case, most of the cost of heating with an electric boiler will be compensated by autonomous heat sources.
The electrical wiring in the house must withstand the maximum power of all electrical equipment, including the boiler. Before choosing a specific model, it is necessary to check the cross-section of the wiring and, if necessary, replace it with a more reliable one.
Gas heating costs calculation
It is much more efficient to use natural or liquefied gas as an energy carrier - its cost will be cheaper. However, in addition to running costs, there are high upfront costs to consider. Correct calculation of gas heating costs should include the following items:
- Registration of permits, purchase of equipment and preparation for its installation;
- The volume of consumed gas, delivery of a cylinder or filling a gasholder for liquefied.
The calculation of expenses for the first item is purely individual in nature. After calculating them, you need to add the amount received to the calculation of the cost of gas heating. It is usually spread over several years. In this way, you can get a relatively accurate amount, including the current initial costs.
Main gas
Unlike the calculation of electricity costs for heating, in addition to gas consumption, it is necessary to take into account the features of the boiler operation. All modern models must be connected to the mains. And although the consumption of electric power will be small, when analyzing seasonal costs, it will occupy some part.
After calculating the heat losses, the choice was made for a 16 kW boiler. For modern models, the consumption of natural gas at maximum operation will be about 1.72 m³ / hour (Navien Turbo). Taking into account the average tariff of 4.68 rubles / m³, you can calculate the cost of heating during the day:
1.72 * 16 * 4.68 = 128 rubles
As you can see, this figure is much less than when planning the cost of heating with electricity. In this case, the maximum power of the boiler was taken into account during the entire period of operation.For this boiler, the electrical power consumption is 150 W / h. Those. the total consumption will be equal to:
128 + 0.15 * 1.63 * 16 * 0.7 + 0.15 * 4.79 * 16 * 0.3 = 128 + 3.9 + 3.44 = 135 rubles
To reduce heating costs with an electric boiler, you can install a hybrid system. It will include a small electric boiler and a liquefied fuel gas plant.
It is not recommended to purchase boilers with a large power reserve. They will have increased gas consumption, which will ultimately affect costs.
Liquefied gas
The calculation method for liquefied gas (propane-butane) is more complicated. This is due to the uneven pressure in the cylinders or gasholder. To correct the actual costs of heating a country house, it is recommended to install an intermediate pumping station - a gas generator. It will maintain the optimal level of pressure in the line.
For such a scheme, you can use two calculation methods. The simple one is that it will take about 0.12 liters to generate 1 kW of thermal energy. (0.00012 m³) gas. For a 16 kW boiler with 16 hours of daily operation, the consumption at a cost of 19 rubles / litas will be:
16 * 0.12 * 16 * 19 = 583 rubles
This value is for the maximum power of the boiler. If we resort to the method of accounting for heat losses, then the estimated amount of costs for gas heating will be at a flow rate of 1.43 kg / h (Navien Turbo boiler):
1.43 * 18 * 19 = 489 rubles
As you can see, given the characteristics of the boiler, you can get a more accurate amount of consumption. That is why, when calculating the cost of heating a brick or frame house, you should familiarize yourself with the technical characteristics of the equipment.
Installation of a gas tank at the stage of purchasing equipment is much more expensive than cylinder heating. But it is much more convenient to use.
Calculating the cost of district heating
Is it possible to save on costs when connecting to a central overhead? The best way is to install heat meters, install bypasses and thermostats. However, for vertical piping, this task is difficult to accomplish, since one apartment can have from 2 to 5 risers. And for each you need to install a counter. The way out of this situation is the allocators of heating costs.
It is installed in front of a heating distribution unit in an apartment building. At the same time, additional temperature sensors are installed in each apartment, signaling the degree of heating in the rooms. Installing a heating cost allocator has the following advantages:
- Automatic adjustment of the heating agent supply volume depending on the outside temperature;
- The ability to set the volume of hot water supply by residents of the house. But this must be agreed with the management company.
It is important that the device of the distributor of heating costs and its operation do not contradict the legislation - Decree of the Government of the Russian Federation of 11/18/2013 N 1034. This should be controlled by the management company that provides heat to the house.
Heating cost allocators may only be installed by licensed companies. This issue must be agreed with the management company, which issues technical specifications and controls the entire process.
What else should be considered when planning the cost of heating a house with electricity and gas? The calculation largely depends on the control and regulation devices for the coolant supply. Therefore, it is imperative to provide for the installation of thermostats, temperature sensors connected to the boiler in the system.
The video shows several practical recommendations for reducing heating costs:
