What should be considered when sizing a circulator for a forced hot water system?

When sizing a circulator for a forced hot water system, the pressure drop measurements are critical because they help determine how much energy the circulator needs to overcome to move the water effectively through the system. This includes accounting for the resistance caused by the length and diameter of the piping, fittings, valves, and other components in the system.

Pressure drop is calculated based on factors such as flow rate, pipe size, and the type of fittings and bends used in the system. By accurately assessing the pressure drops, you can select a circulator that provides adequate flow while maintaining the system's efficiency and performance.

Considering the pressure drop ensures that the circulator is not too small, which would lead to insufficient flow and possibly cause overheating, nor too large, which could result in excessive energy consumption and shorten the lifespan of the equipment. This careful balancing act directly impacts the overall efficiency of the heating system.