Primary heating circuit (definition)

Primary heating circuit (boiler circuit) — is the main circuit in a heating system that is responsible for transferring heat from a heat source, such as a boiler, to the primary elements of the system, such as heat exchangers or pumps.

Primary heating circuit: main aspects

1. Function:
   • Heat transfer: The primary circuit is designed to transport hot coolant from the boiler or other heat source to heat exchangers, radiators or other elements of the heating system.
   • Temperature regulation: This circuit often contains temperature control components such as three-way valves and pumps.
2. Design:
   • Pipeline network: Includes pipes that connect the boiler to heat exchangers or other elements, ensuring efficient circulation of hot coolant.
   • Pumps: Provide forced movement of the coolant along the circuit network, maintaining the required pressure and flow.
   • Regulators: Includes temperature and pressure monitoring devices such as thermostats and pressure gauges.
3. Principle of operation:
   • Heat: The coolant heated in the boiler enters the primary circuit, where it transfers its heat to the heat exchangers.
   • Circulation: Pumps in the primary circuit ensure constant movement of the coolant, which allows for uniform distribution of heat throughout the system.
4. Difference from secondary circuit:
   • Primary circuit: Connects the heat source to heat exchangers or radiators where the primary heat transfer occurs.
   • Secondary circuit: Uses heat obtained from the primary circuit to distribute heat to individual zones or circuit systems such as underfloor heating or individual radiators.
5. Advantages:
   • Efficiency: Provides direct heat transfer from the source to the primary elements of the system, resulting in faster and more efficient heating.
   • Adjustment: Possibility of installing various regulators and controllers for precise adjustment of the heating system operation.
6. Service:
   • Checking and cleaning: Regular inspection and maintenance of the primary circuit is necessary to prevent blockages and ensure efficient system operation.
   • Calibration: Adjust thermostats and pumps to maintain optimal circuit operation.

Application:

The primary heating circuit is used in heating systems with various heat sources, including boilers, heat pumps and solar collectors. Efficient operation of the primary circuit is critical to the overall functioning of the heating system and to ensuring comfortable temperatures in the premises.