A circulator pump (or recirculator pump) is a specific type of pump used to circulate water through your plumbing system. Because they only circulate liquid within a closed circuit, they only need to overcome the friction of a piping system (as opposed to lifting a fluid from a point of lower potential energy to a point of higher potential energy).
Circulator pumps are usually electrically powered centrifugal pumps. As used in homes, they are often small, sealed, and rated at a fraction of a horsepower, but in commercial applications they range in size up to many horsepower and the electric motor is usually separated from the pump body by some form of mechanical coupling. The sealed units used in home applications often have the motor rotor, pump impeller, and support bearings combined and sealed within the water circuit. This avoids one of the principal challenges faced by the larger, two-part pumps: maintaining a water-tight seal at the point where the pump drive shaft enters the pump body.
Hot Water Instantly!
Installing a circulating pump to circulate hot water so that a faucet will provide hot water instantly upon demand. This conserves time, energy and water. In Oklahoma City, where water conservation has become important with rapidly expanding and urbanizing population, circulator pumps are becoming the popular solution.
In a typical one-way plumbing system without a circulation pump, water is simply piped from the water heater through the pipes to the tap. Once the tap is shut off, the water remaining in the pipes cools producing the familiar wait for hot water the next time the tap is opened. By having Mr Rooter add a circulator pump and constantly circulating a small amount of hot water through the pipes from the heater to the farthest fixture and back to the heater, the water in the pipes is always hot, and no water is wasted during the wait.
Thermostatically Controlled Circulation Pump
While the majority of these pumps mount nearest to the water heater and have no adjustable temperature capabilities, a significant reduction in energy can be achieved by utilizing a temperature adjustable thermostatically controlled circulation pump mounted at the last fixture on the loop. Thermostatically controlled circulation pumps allow owners to choose the desired temperature of hot water to be maintained within the hot water pipes since most homes in Oklahoma City do not require 120 °F (49 °C) degree water instantly out of their taps. Thermostatically controlled circulation pumps cycle on and off to maintain a user’s chosen temperature and consume less energy than a continuously operating pump.
The traditional hot water recirculation system uses a dedicated return line from the point of use located farthest from the hot water tank back to the hot water tank. In homes where this return line was not installed the cold water line is used as a return line. The first of two system types has a pump mounted at the hot water heater while a “normally open” thermostatic control valve gets installed at the farthest fixture from the water heater and closes once hot water contacts the valve to control crossover flow between the hot and cold lines. A second type of system utilizes a thermostatically controlled pump which gets installed at the farthest fixture from the water heater. These thermostatically controlled pumps often have a built-in “normally closed” check-valve which prevents water in the cold water line from entering into the hot water line.
Compared to a dedicated return line, using the cold water line as a return has the disadvantage of heating the cold water pipe (and the contained water). Accurate temperature monitoring and active flow control can minimize loss of cold water within the cold water line. Technological advancements within the industry allow for incorporating timers to limit the operations during specific hours of the day to reduce energy waste by only operating when occupants are likely to use hot water. Additional advancements in technology include pumps which cycle on and off to maintain hot water temperature versus a continuously operating pump which consumes more electrical energy.
Reduced energy waste and discomfort is possible by preventing occurrences of hot water line siphoning in open-loop hot water circulation systems which utilize the cold water line to return water back to the water heater. Hot Water Line Siphoning occurs when water from within the hot water line siphons or is forced into the cold water line due to differences in water pressure between the hot and cold water lines. Utilizing “normally closed” solenoid valve significantly reduces energy consumption by preventing siphoning of non-hot water out of hot water lines during cold water use. Using cold water instantly lowers the water pressure in the cold water lines, the higher water pressure in the hot water lines force water through “normally open” thermostatic crossover valves and backflow check valves (which only prevent cold water from flowing into hot water line), increasing the energy demand on the water heater.
Circulator Pump Optimizing
In the past circulating pumps operated continuously 24 hours a day or utilized a timer to schedule operating times around anticipated hot water demand periods. In a residential environment where occupant’s lifestyles are anything but routine, using a 24-hour timer to schedule circulator pump operations would not be practical. Growing environmental concerns call for greener eco-friendly products capable of satisfying consumers with different lifestyles.
Mr Rooter can adapt an intelligent circulating pump control to an existing system. This instantly adds greener control capabilities like; cycle on and off based on a temperature set point (fixed/adjustable) or time-of-day or day-of-week or push-button on-demand or occupancy sensor or sound sensor and more. Minimizing circulator pump operations saves valuable resources and the environment.