AT-01-08-2 -- Dual Set Point Control of Open-Loop Heat Pump Systems ✓ Most Recent

Control of well pumps in open-loop heat pump systems is a topic that has been largely overlooked in related literature. Three primary methods in use are dual set point, variable speed, and multiple well (normally employed when multiple wells are required for hydrologic or redundancy). This paper explores the issues involved in the dual set point method. Establishing the system operating set points requires consideration of peak loop loads, loop thermal mass, well pump motor cycling limitations, and heat exchanger performance. Guidelines for pump controller operating range are presented along with the method of establishing the optimum loop temperatures at peak load conditions.

Units: Dual