Domestic hot water recirculation loop

Domestic hot water recirculation loops are used to circulate water from the water heater to the point of use and back. A hot water line connects the water tank to one or more fixtures (in series), and returns to the tank. Water is circulated through this loop by a pump, either continuously, on a set schedule, or under temperature control. The use of such a loop has the potential to reduce the wait time for hot water at the point of use, and thus, reduce the amount of cold water sent down the drain.

In January 2010, a DHW recirculation loop was installed in the CCHT Reference house from the water heater to the second floor shower and back. The loop was operated with three different control strategies: continuous operation, scheduled operation (20 minutes prior to each shower), and temperature control. The objective of the project was to determine the impact on water temperature, the potential for water savings, and the effect of loop heat losses on total home energy consumption.

This project is currently at the reporting stage.