If you have ever stood by and watched gallons of water pour down the drain while waiting for hot water to arrive at your shower, sink, or other fixture, you know the frustration and waste that occur when hot water travels a long distance from the water heater. A recirculation system can eliminate wait times and reduce energy costs.
Many hot water recirculating system in NYC use a pump to speed up hot water transmission to point-of-use fixtures. They run on electricity, but their energy consumption is minimal compared to heating water in the traditional plumbing system. Some of these pumps are programmed to detect the hot water temperature in the pipes and only recirculate the water when it has cooled down, saving even more energy.
In addition, the energy efficiency of these systems is greater than a passive return line or simple piping layout in some cases. In new homes, we recommend using an on-demand style system so that the water heater only uses energy when needed and the recirculation pump runs for as little as possible. While some may be concerned about an incremental increase in energy costs, the convenience and comfort of instant hot water are often worth it for many people.
In homes with long plumbing runs between the water heater and faucets, it can often take a minute or more for hot water to reach the tap after you turn on the faucet. This is inconvenient, and wastes water and energy as the unused hot water in the pipes cools down to room temperature.
Hot water recirculating systems can reduce this wasted water and energy by keeping the hot water in the supply pipe hot at all times. These systems usually run on either a thermostat or a timer. Systems that run on a timer offer more control over the system’s operation, which can help save even more energy and money.
If you are considering a recirculating system, choose an efficient one with a timer that only operates when needed. Of course, you can also save on energy costs by insulating your water lines to minimize heat loss. The combination of instant hot water and reduced water waste makes this an appealing option for many homeowners.
In addition to reducing energy bills, a recirculating system provides a convenience that many homeowners find desirable. If you live in an older home with long plumbing runs, hot water can sometimes take minutes to reach a shower or sink. During this time, the cold water that hasn’t been used goes down the drain and loses heat.
With a recirculating system, the pump continually keeps the pipes heated so that the hot water is already there when you turn on a tap. This allows you to wash dishes, shower, and wash your hands quickly without waiting for the water to warm up.
Some systems, called passive recirculating systems, use natural thermal convection to keep the water hot instead of a pump. These systems are less expensive than a traditional recirculating system but still require a dedicated return line to work. If you’re building a new home, consult your builder to ensure your home is designed with a return line.
While the energy saved by a hot water recirculating system is significant, it can’t completely offset the energy used to run the pump. However, the best option to reduce this cost is to install a demand-style system that only runs when water is needed. This type of system wastes less electricity than other recirculation systems because it doesn’t keep reheating the same water in the supply pipes constantly.
For those who want to limit their use of a recirculation system, we recommend that their plumbing contractor insulate their pipes and consider using a tankless water heater that doesn’t require a continuous pump. However, convenience and comfort trump energy concerns for many homeowners who are frustrated by waiting for hot water.
They’ll likely accept a little wait time in exchange for the savings and efficiency they get from a recirculating system. The return on investment is a very attractive one! The average recirculation system pays for itself in less than two years.