Heating systems are autonomous or centralized. As a coolant, as a rule, water is used. Uninterrupted and safe operation of the entire structure depends on the accuracy of calculations and installation of all components.
Instruction manual
1
One of the important indicators ensuring the optimal functioning of the heating system is pressure. It can be static (acts on the bottom of the tank and depends on its height and volume) and dynamic (occurs when the coolant moves and affects the entire working area of the system). The system operating pressure must be below the maximum allowable limit. The upper value is considered acceptable, at which the operation of the pump and the entire system is still optimal.
2
The operating pressure in the heating system depends on the volume of the coolant, the capacity of the boiler, the diameter of the pipes, the height difference in the zones of supply and return of water. Calculation of the volume of water in an autonomous system is made from the condition: 13 l per 1 kW of boiler power. And for a boiler with a capacity of 10 kW it will be: 10 * 13 = 130 (l). A water meter will help to find out the existing volume of water in the system. If the actual value is lower than the calculated value, it must be increased by adding heating sections. And vice versa.
3
The limit pressure value is indicated in the boiler passport and rarely exceeds 1.2 atmospheres. Deviation from the set value leads to equipment breakdown (if the pressure is below normal) or destruction of the entire system (if the pressure is above normal).
4
For an autonomous heating system, the initial (starting) pressure is 1.5 atmospheres. As heating (up to 95 ° C) and water expansion (on average by 5%) in the system, this value can reach 2 atmospheres. At this point, excess coolant is discharged into the expansion tank, designed to compensate for differences in operating pressure. Its capacity is 12% of the total volume of water, plus 5% for expansion of the coolant. For a 10 kW boiler, the capacity will be: (130 * 12%) * 5% = 16.38 (l). When calculating the starting pressure in the tank, 0.2 bar is added to the difference in static pressure in the upper and lower levels of the system.
5
In a centralized closed-circuit heating system under ideal operating conditions, the pressure can reach 9.5 atmospheres. Due to all kinds of leaks, it often drops to 5.5 atmospheres. The reasons for this are: deterioration of equipment (pumps, generators, pipes), remoteness of the house from the boiler room, remoteness of the apartment from the central riser of the heating main, changes in the diameter of the pipes by tenants, when replacing batteries (decreasing the diameter increases pressure and vice versa). All these indicators are taken into account by the boiler house workers in order to maintain the required pressure (stipulated by GOST).
