It's not often that homeowner conveniences favor the environment. But here's one that does. Spurred by consumer demand for hot water instantly at the tap, new technology satisfies not only our impatience, but water conservation as well. Domestic hot water recirculation (HWR) is now one of the fastest-growing trends in the plumbing industry, rivaling the push for bigger baths and more luxurious showers.

Statistics show that recirculation systems save about 11,000 gallons of water each year for a family of four, water that's otherwise wasted as people wait unnecessarily for hot water at taps and showers. In larger homes with more fixtures and longer water lines between the water heater and distant bathrooms, the amount of water that's wasted can be much higher than that. In most cases, homeowners not only pay for the water that goes down the drain, but to get rid of it as well.

This has become an important issue for homeowners - if not the inconvenience factor, certainly the wasteful loss of water down the drain. Most builders, remodelers, architects and designers have heard about it from customers, or in conversation with plumbing subcontractors. And, if not… you will soon.

The phrase that sums up the essence of this new technology is “constant circulation” of domestic water within the home. A few leading manufacturers now offer inexpensive technology that prevents the wait for hot water, and the waste.

Ready To Retrofit - An Easy Fix

Comfort System technology from Grundfos (Olathe, Kan.), sold to plumbing and mechanical contractors through wholesale distribution, is the latest in hot water recirculation (HWR) solutions. It's a one-pump, one-valve combo that's typically installed by a professional within an hour or two - without the need to install a return line to the water heater. The unit provides greater convenience and comfort, delivering hot water instantly from any water source the home.

“There's a timer on the pump to make it more efficient during evening and mid-day downtime - homeowners can dial-in what time they want the system to be operational,” explained Dave Yates, president of York, Pa.-based plumbing and mechanical firm, F.W. Behler, Inc. The unit begins working when the timer-activated pump at the hot water tank pushes hot water toward a valve beneath the furthest fixture in the house. The valve connects the hot and cold water supply lines.

As long as the water in the hot line is less than 98 degrees Fahrenheit, the valve stays open and the cold water is sent back to the heater through the cold water line. Hot water stands ready to come out when the tap is turned on. When the hot side of the tap reaches 98 degrees Fahrenheit, the “recirc” valve closes, stopping circulation, and reopens when temperature calls for it.

An Even Easier Solution For New Homes

The UP10-16 by Grundfos is designed for new home installations, when a dedicated return line is installed by the plumbing contractor, completing a separate recirculation loop. The one-piece HWR device is easily installed at the water heater. It constantly monitors the temperature in the hot water line and is self-activating, but only if it's within the operational periods that are set by the homeowner (there's no need to circulate hot water in the middle of the night, so the systems are usually in an idle mode).

“Both of these solutions circulate water back to the heater so it's always hot and comfortable from the moment it's needed at the tap or shower,” added Yates. “These units give homeowners a much more responsive system, and save water.”

The only downside to the technology is that, though huge amounts of water are saved, minimally more energy is used for water heating. That's because the water is cycled through the lines continuously, even when not in use. Though, if the domestic water lines are insulated, and the timers are set to recycle water only during critical periods, the additional energy required would be negligible.