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Nearly everyone is familiar with the ritual of turning on their shower valve and letting the cold water run out before getting in the shower, or for that matter doing the same thing at the sink before washing his hands. This is not only an annoying waste of time, but a tremendous waste of water as well.

While fresh water becomes scarcer in the face of ever-increasing public demands for it, more water continues to be wasted. The typical U.S. home wastes between 12,000 to 38,000 gallons of water each year waiting for hot water. (see more water facts)

This water places an unnecessary burden on municipal wastewater treatment systems and other infrastructures. This wasted water poured down the drain was heated and now when the water is shut off the hot water remaining in the pipes will just cool down again. Throwing HOT paid-for water down the drain not only aggravates shortages but also adds needless demands on our water producers and our Gas and Electric service providers.

In addition, all water heaters experience stand-by losses and operating stress; they cycle on and off several times during the day.

In typical plumbing, water is pumped from the water heater through the pipes to the faucet/tap. Once the faucet is shut off, the water remaining in the pipes cools - hence the familiar wait for hot water the next time the tap is opened.

A recirculation pump reduces undo stress on the tank caused by the thermo shock of new cold water entering the system, by tempering this new water with the returning warm water.

Recirculation decreases the amount of cold water that enters the system, and that results in much less condensation and less thermal stress on the tank. Yet the actual circulator requires a minimal horsepower motor in the range of 1/12 or 1/16 hp, or just enough to keep the water moving.

A recirculating pump brings instant hot water to any room in the house There are two types of recirculating systems, closed systems and open ones.

A closed system is like that found in a hot water heating system, where radiant heat from the water is used to heat the home. The system is always full and water is neither added nor removed. As a result, the quality of this water deteriorates to the point where it is not safe for drinking.

An open system, on the other hand, allows both the inflow and outflow of water during the recirculating process.

This is the type of system we're discussing in this article. Unlike closed systems, where the water is subject to the infiltration of impurities, open systems must maintain water integrity.

The solution to this problem is the recirculating pump, an item that's becoming more and more popular in new homes. Besides adding value to the home, it provides the comfort and convenience of instant hot water at every faucet and valve, without the prohibitive cost of installing instant water heaters in each location.

All the faucets, showers and water appliances are linked (in series) by the piping in a continuous line. At the last faucet or water fixture (farthest from the hot water heater), a return pipe is installed that goes back to the water heater. This is called the "hot" pipe loop. Water in these pipes is always hot

How the loop is made, depends on the type of installation:

New Home Construction
This system requires a dedicated return-line to be installed from the end of the hot water supply line back to the water heater.

A circulator pump is used to circulate water through the main hot water line and the return-line back to the water heater to keep hot water in the main line. A timer, aquastat, or both may be used to control the operation of the pump. The Grundfos UP 10-16's, as well as the UP Bronze and Stainless model circulators are common in this application. Learn More »

Retrofit Solution
The Grundfos Comfort System is a pump and valve combination that delivers you hot water in an instant to any faucet or bath in your home.

This combination works together to keep the water in your hot water line at temperature to provide "no-wait" hot water throughout your home. The timer on the pump makes it more efficient during downtime, like nights or mid-day. It's quiet, maintenance-free, and keeps your water at a comfortable temperature.. Learn More »

See Also:

Centrifugal Pumps
Recirculation Pumps
Sewage Ejector Pumps
Sump Pumps
Well Pumps

Links to Related Websites:
Water Facts
Grundfos Hot Water Recirculation - FAQs
Grundfos Hot Water Recirculation News and Information


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