Hot water recirculating system with dedicated return line

Table of Contents Show

How a Hot Water Recirculation Pump Works
Does a recirculating pump need a return line?
What is a dedicated hot water return line?
What is a dedicated recirculation line?

How a Hot Water Recirculation Pump Works

Hot water recirculation pumps work by generating a continuous flow of hot water in your home’s hot water supply line. Systems are available for existing homes and new homes. For an existing home, a retrofit system will work with your cold water line at three points – pipe, pump, and valve (installed at the furthest fixture)– using the cold water line to create a return line. For new construction homes, a dedicated return line is installed and a circulator pump where the return line meets the hot water heater.

Three Major Benefits to Hot Water Recirculation Pumps:
1. Saving Money. Sending rivers of clean water down your drain every year simply isn’t cost-effective. A hot water recirculation system cuts back on water usage, which means savings on your water bill.
2. Convenience. Waiting for hot water is a pain. Hot water recirculation is becoming the standard for new construction homes for a reason: it’s a more pleasant, more efficient system
3. Conserving Water. As you probably know from various water conservation awareness campaigns, fresh water is a precious resource. Hot water recirculation is a cost-effective means of controlling water waste.

Activation
Hot water recirculation systems are most commonly activated by either a thermostat or a timer. Systems that use a thermostat or timer automatically turn the pump on whenever the water temperature drops below a set point, or when the timer reaches a certain setting. These systems ensure that hot water is always available at the faucet.

Do they really save energy and water?
Regardless of whether they are controlled manually or automatically, recirculation systems reduce the amount of water that goes down the drain while the homeowner waits for the desired temperature. This fact allows for the following three advantages over conventional water distribution systems:

They save time. Recirculating systems deliver hot water to faucets quickly, adding convenience for the homeowner.
They conserve water. According to statistics from the U.S. Department of Energy and the U.S. Census Bureau, between 400 billion and 1.3 trillion gallons of water (or close to 2 million Olympic-sized swimming pools) are wasted nationally by households per year while waiting for water to heat up.
They limit municipal energy waste. The DOE estimates that 800 to 1,600 kilowatt-hours per year are used to treat and pump the water to households that will eventually be wasted while the occupant waits for tap water to warm to the desired temperature.

If recirculation systems pump continuously, however, they have the potential to use significantly more energy. For a modest-sized pump, this might be 400 to 800 KWH a year if the pump runs all the time. Also, heat loss from the pipes can be significant if the hot water pipes are poorly insulated. This will result in the hot water heater running more. This added heat may be a benefit in the winter, but heat loss may add heat to the house in the summer and may result in higher bills for use of air conditioning.

Rebates
Some jurisdictions, particularly in areas where water is scarce, offer rebates on the purchase and installation of hot water recirculation systems. The cities of Santa Fe and Albuquerque, New Mexico, for instance, offer a $100 rebate for homeowners who purchase a hot water recirculation system. The city of Scottsdale, Arizona, offers up to $200 for residential property owners who install theses systems, although they must comply with UL-product and installation standards. Some systems may not comply with efficiency standards set by these municipalities.

Availability and Cost
Hot water recirculation systems are available nationwide from manufacturers, distributors, plumbing wholesale supply warehouses, and at selected retail home stores. The initial cost of dedicated systems may prevent some homeowners from installing these systems, as they require the purchase and installation of a pump and a large amount of piping. Integrated systems, by contrast, require only a pump and fittings. Energy savings will vary, depending on the design of the plumbing system, method of control and operation, and homeowner use. The system is easily installed and costs less than $400.

Inspection Considerations

These systems all require an in-line air valve and shut-off valve. Other requirements will vary with the installation's configuration, but may include a check valve and an additional shut-off valve. The pump may be connected to a sensor with high and low temperature limits so that the pump circulates water through the loop only when the sensor calls for it.

Inspections should be limited to the system's proper operation.

Does a recirculating pump need a return line?

Not every domestic hot water recirculation system requires a return line. For residential and light commercial applications, there is another way to save water and maintain hot water at the last fixture.

What is a dedicated hot water return line?

In a traditional hot water recirculating system, there is a dedicated return line for the hot water pipes, which runs from the furthest bathroom or fixture back to the water heater. Near the water heater area, a recirculating pump pulls the water from the furthest fixture back into the water heater, creating a loop.

What is a dedicated recirculation line?

The Dedicated Recirc System converts an existing hot water circulation line into an efficient on-demand delivery system. The Dedicated Recirc System delivers hot water only when there is a demand: Reducing Energy Costs. Virtually Eliminating Pinhole Leaks.