The calculated, normative and actual indicators of the specific thermal characteristics are the main markers used by specialists in the field of heat engineering. The figures are of practical importance for consumers of their own and multi-storey buildings. The delta between the calculated and actual values is the energy efficiency coefficient of the premises, which reflects the economy of thermal communications.
The concept of the specific thermal performance of a building
The specific thermal characteristic of a building is an important technical parameter that is contained in the passport. Calculation is required when designing and constructing a building. Knowledge of the markers is necessary for the consumer of thermal energy, since they affect the rate indicator. Specific characteristic implies the presence of the largest heat flux required to heat the room. When calculating the indicator, the difference between the street and indoor indicator is measured by 1 degree. The parameter is an indicator of the energy efficiency of the room. The average coefficient is fixed in the regulatory documents. The change in markers reflects the energy efficiency of the system. The calculation of the parameters is carried out according to the established rules of SNiP.
Method for calculating the specific thermal characteristics
The specific heating characteristic can be calculated-normative or actual. The first way involves using formulas and tables. The actual figures are to be calculated, but the exact results are determined by a thermal imaging survey of the building.
Settlement and normative
The calculated data is calculated using the formula
Where:
- qbld (W / (m3oC)) - an indicator of the heat lost by one cubic meter of a building with a temperature difference of 1 degree;
- F0 (m2) - marker of the heated area;
- Fst, FOK, Ffloor, Fpok (m2) Is an indicator of the area of walls, windows and coverings;
- Rt.st, Rcurrent, Rt floor, Rso - marker of resistance to heat transfer by the surface;
- N- coefficient, which depends on the position of the room relative to the street.
The actual parameters are used in the calculation:
- Q - fuel consumption marker;
- Z is the coefficient of the duration of the heating season;
- Tint - indicator of the average air temperature in the room;
- Text - marker of average outdoor temperature;
- Q is the coefficient of the specific thermal characteristics of the room.
This calculation is most often used because it is simpler. However, there is a significant disadvantage that affects the accuracy of the final result: the temperature difference in the premises of the building is taken into account. To obtain the most informative data, they resort to calculations that determine the heat consumption in terms of heat loss in various buildings and data from design documentation.
The actual
Self-regulatory organizations use their own methods.
They contain:
- planning data;
- components of architecture;
- year of construction of the building.
- outdoor air temperature markers during heating season.
In addition, the specific indicator of the heating characteristic is determined taking into account the heat loss in pipes passing through cold rooms, as well as the consumption for condensate and ventilation. The coefficients are contained in the SNiP tables.
Determination of the energy efficiency class
The definition of a marker is based on the following data:
- Change in actual and calculated normative markers. The first are obtained by a practical method, as well as by means of a thermal imaging survey.
- Characteristics of the climate of the area.
- Regulatory data on heating and ventilation costs.
- Building type.
- Technical data of building materials.
Each energy efficiency class has a certain value of resource consumption per year. The indicator is contained in the passport of the house.
Basic methods to improve energy efficiency
Optimization of performance implies a reduction in heating tariffs due to improved thermal insulation.
The main methods include:
- Increasing the level of thermal resistance of a building under construction. Wall cladding is being carried out, ceilings are finished with heat-insulating materials. The energy saving indicator goes up to 40%.
- Elimination of cold bridges in a building under construction. Energy savings increase by 3%.
- Glazing of loggias and balconies. The method optimizes heat retention by 10-12%.
- Installation of innovative models of windows with profiles containing several cameras.
- Ventilation system installation.
Residents can also increase the degree of thermal insulation. Among the main methods, it should be noted:
- installation of aluminum radiators;
- installation of thermostats;
- installation of heat meters;
- installation of screens that reflect heat flows;
- the use of plastic pipes in the heating system;
- installation of an individual heating system.
By increasing energy efficiency, you can reduce the cost of ventilation of the room. It is recommended to use:
- window micro-ventilation;
- a system with heated air that comes from outside;
- regulation of air supply;
- protection from drafts;
- ventilation systems with motors of different capacities.
Improving the energy efficiency of an apartment building requires high costs. Sometimes the problem remains unresolved. Reducing heat loss in a private home is simple. It is achieved in a variety of ways. With an integrated approach to the problem, a positive result is achieved. Heating costs depend on the characteristics of the system.
Private sector houses are occasionally connected to central communications. For the most part, they have an individual boiler room. Installation of a modern system, which is distinguished by a high level of efficiency, helps to reduce heat costs. The gas boiler becomes the best choice. Equipping the boiler with additional equipment is also shown. For example, installing a thermostat can save up to 25% on fuel consumption. Installation of additional sensors helps to increase the savings in gas consumption.
The functionality of most autonomous systems is based on forced circulation of the coolant. For this purpose, a pump is installed in the network. The equipment must be reliable and of high quality. But these models use a lot of energy. In houses with forced circulation, 30% of the costs are spent on operating the circulation pump. On the market there are grades of class A units that are distinguished by energy efficiency.
Heat retention is provided by the thermostat. The operation of the sensor is simple. The air temperature is read inside the heated room.As a result, the pump is in the off and on mode depending on the temperature in the apartment or house. The response limit and temperature conditions are set by the user. Residents use an autonomous heating system and get a good microclimate, as well as savings in fuel consumption. The main priority for thermal protection thermostats is to turn off the heater and circulation pump. The equipment remains operational.
There are other methods to improve energy efficiency:
- insulation of walls and floors using innovative heat-insulating materials;
- installation of plastic windows;
- protection of premises from drafts.
All methods make it possible to increase the actual indicators of thermal protection of the building relative to the calculated and standard indicators. The enlarged marker reflects the degree of comfort and economy.
