Do hot water recirculation systems work?
Heating water uses up to one-third of energy in homes, much of which is lost as the water travels through pipes. Additional energy is required to operate pumps and reheat water in continuous hot water circulation loops. And when the source of hot water is far from plumbing fixtures, significant amounts of water are wasted while you’re left waiting for hot water to arrive.
But there’s a solution. Efficient hot water distribution systems save both energy and water by delivering hot water quickly and with minimal wasted water. This is best accomplished by locating fixtures as close as possible to water heaters. If that’s not an option, alternative strategies include demand-controlled circulation loops and, in exceptional situations, electric heat traced pipes.
In all cases, all hot water pipes should be insulated for maximum efficiency. Insulated trunk lines often maintain the temperature long enough to provide consistent hot water in the system through multiple uses, such as morning showers.
For other information on residential hot water distribution systems, visit the Alliance for Water Efficiency.