Gas costs in an apartment or private house building are calculated to determine the costs of heating, water heating and cooking. The calculation is made at the design stage or before the purchase of boiler equipment. The average and maximum gas consumption in these cases is calculated according to a certain method, the result gives an idea of the amount of fuel consumed.
- Influence on gas consumption
- Gas consumption calculation
- By boiler power
- By quadrature
- Depending on pressure
- Calculation by diameter
- Taking into account heat loss
- By counter and without
- Calculation of the consumption of liquefied gas
- Calculation for 1 kW of heat
- What amount of heat is given off by liquefied gas and natural
- Reducing gas consumption
- Insulation of walls, roofs, ceilings
- Replacing windows
- other methods
Influence on gas consumption
Gas consumption depends on various factors. Boilers are installed in large houses, which consume more fuel mixture than units in small buildings or apartments.
Fuel consumption is affected by:
- boiler power;
- outside temperature;
- the quality of the gas mixture.
Some gas distribution companies supply undried gas mixtures that contain moisture and impurities into the pipeline. The calorie content decreases and the volume consumed increases.
Gas consumption calculation
The power of the boiler or convector depends on the heat loss in the building. The average calculation is carried out taking into account the total area of the house.
When calculating the gas consumption, the heating rates per square meter are taken into account at a ceiling height of up to 3 m:
- in the southern regions, 80 W / m² is taken;
- in the north - up to 200 W / m².
The formulas take into account the total volume of individual rooms and premises in the building. For heating each 1 m³ of the total volume, 30 - 40 W is allocated, depending on the area.
By boiler power
The calculation is based on the heating capacity and area. The average consumption rate is applied - 1 kW per 10 m². It should be clarified that it is not the electrical power of the boiler that is taken, but the thermal power of the equipment. Often such concepts are substituted, and an incorrect calculation of gas consumption in a private house is obtained.
The volume of natural gas is measured in m³ / h, and liquefied gas - in kg / h. Practice shows that to obtain 1 kW of thermal power, 0.112 m³ / h of the main fuel mixture is consumed.
By quadrature
Specific heat consumption is calculated according to the formula presented if the difference between outdoor and indoor temperatures is approximately 40 ° C.
The ratio used is V = Q / (g K / 100)where:
- V - volume of natural gas fuel, m³;
- Q - thermal power of the equipment, kW;
- g - the lowest calorific value of gas, usually equal to 9.2 kW / m³;
- K - coefficient of efficiency of the installation.
Depending on pressure
The volume of gas passing through the pipeline is measured by a meter, and the flow rate is calculated as the difference between the readings at the beginning and end of the path. The measurement depends on the pressure threshold in the converging nozzle.
Rotary counting devices are used to measure pressure over 0.1 MPa, and the difference between outside and inside temperatures is 50 ° C. The gas fuel consumption indicator is read under normal environmental conditions. In industry, proportional conditions are considered to be a pressure of 10 - 320 Pa, a temperature difference of 20 ° C and a relative humidity of 0. Fuel consumption is expressed in m³ / h.
Calculation by diameter
The gas velocity in a high-pressure gas pipeline depends on the cross-sectional area of the collector and averages 2 - 25 m / s.
The throughput is found by the formula: Q = 0.67 · D² · pwhere:
- Q - gas consumption;
- D - nominal bore diameter of the gas pipeline;
- p - the working pressure in the gas pipe or the absolute pressure of the mixture.
The value of the indicator is influenced by the outside temperature, heating of the mixture, excess pressure, atmospheric characteristics and humidity. The calculation of the diameter of the gas pipeline is done when drafting the system.
Taking into account heat loss
To calculate the consumption of the gas mixture, it is required to know the heat losses of the structure.
The formula is used Q = F (T1 - T2) (1 + Σb) n / Rwhere:
- Q - heat loss;
- F - the area of the insulating layer;
- T1 - outside temperature;
- T2 - internal temperature;
- Σb - the amount of additional heat losses;
- n - Coefficient of location of the protective layer (in special tables);
- R - resistance to heat transfer (calculated on a case-by-case basis).
Determination of heat loss is a complex calculation and is carried out by specialists at the project stage. You can order the finding of losses at any stage of the operation of the structure.
By counter and without
The device determines the gas consumption per month. Standard mix rates apply if no meter is installed. For each region of the country, the standards are set separately, but on average they are taken at the rate of 9 - 13 m³ per month per person.
The indicator is set by local governments and depends on climatic conditions. The calculation is carried out taking into account the number of owners of the premises and people actually living in the specified living space.
Calculation of the consumption of liquefied gas
Gas calculation using propane or butane has its own characteristics, but does not present any particular difficulties. What matters is the density of the combustible substance, which changes with an increase or decrease in temperature and depends on the composition of the gas mixture. Only the weight of the liquefied fuel remains constant.
The volume of gas used differs in winter and summer, so it makes no sense to use units of m³ to determine the consumption of liquefied gas per 1 kW of heat, for designation kilograms are taken, which do not change with the change of seasons.
Calculation for 1 kW of heat
The quantity is calculated for heating the house and heating the water in the system. If food is cooked on gas, this must be taken into account additionally.
The formula is used Q = (169.95 / 12.88) Fwhere:
- Q - fuel weight;
- 169,95 - annual amount of kW for heating 1 m² of the house;
- 12,88 - calorific value of propane;
- F - the square of the structure.
The resulting value is multiplied by the cost of 1 kg of the liquefied mixture to calculate the cost of purchasing the required amount. The price is usually given for 1 kg, and not for 1 m³, which should be taken into account.
What amount of heat is given off by liquefied gas and natural
A mixture of butane and propane is used as the condensed fuel. A similar indicator of the substance is 9 thousand 500 kcal / m³. The vapor phase of the mixture (combustible suspension in m³) is calculated when liquid liters are evaporated (in kilograms or liters).
Reducing gas consumption
Gas savings are directly related to a decrease in heat loss. Fencing structures, such as walls, ceiling, floor in the house, must be protected from the influence of cold air or soil. Automatic adjustment of the heating equipment operation is used for the effective interaction of the outdoor climate and the intensity of the gas boiler operation.
Insulation of walls, roofs, ceilings
The outer heat-shielding layer creates a barrier to the cooling of surfaces in order to consume the least amount of fuel.
Statistics show that part of the heated air escapes through the structures:
- roof - 35 - 45%;
- non-insulated window openings - 10 - 30%;
- thin walls - 25 - 45%;
- entrance doors - 5 - 15%.
The floors are protected by a material that has a permissible moisture permeability according to the norm, since when wet, thermal insulation characteristics are lost. It is better to insulate the walls from the outside, the ceiling is insulated from the attic side.
Replacing windows
Modern metal-plastic frames with two- and three-circuit double-glazed windows do not allow air flows and prevent drafts. This leads to less loss through the gaps that were in the old wooden frames. For ventilation, swing-out mechanisms of the sash are provided, contributing to the economical consumption of internal heat.
Glasses in structures are pasted over with a special energy-saving film, which allows ultraviolet and infrared rays to pass through, but prevents their reverse penetration. Glasses are supplied with a network of elements that heat the area to thaw snow and ice. Existing frame structures are additionally insulated with plastic wrap from the outside or blackout curtains are used.
other methods
It is beneficial to use modern gas-fired condensing boilers and install an automated coordination system. Thermal heads are installed on all radiators, and a hydraulic arrow is mounted on the piping of the unit, which saves 15-20% of heat.
In the heating system, detectors and temperature regulators are installed, which regulate the boiler output depending on the state of the outdoor climate. If the weather is warm outside, it is more effective and economical to switch to heating with air conditioners.
