Question

I am considering a water recirculation system for a second home, but for the next 10 years I'll be there only once/mo. Should I bother?

Asked by Steve Goldman
San Tan Valley, AZ

Is a water recirculation system something that can be added later, or would the system be suboptimal if not installed when the home is built?

Answer

Raymond Pruban

Answered by Raymond Pruban

White Bear Lake, MN

Amaris Custom Homes

November 19, 2010

This is kind of a "can of worms" question for sure.

First, let's take a look at the advantages and disadvantages of a hot water recirculation pump for domestic hot water.

Advantages of a Recirculation Pump

  1. When you turn on the hot water, it will instantly be hot, which of course is a very nice creature comfort.
  2. The fact that the water is instantly hot means you are not flushing good drinkable (potable) water down the drain (waiting for hot water). Keep in mind if you are hooked up to city services you pay for both the unused cold water and associated sewer charges.
  3. Water recirculated to the water heater will typically be warmer than incoming water from the ground. This means it takes much less energy to heat the water to temperature.

Disadvantages of a Recirculation Pump

  1. You are running an electric pump that is using electricity and it will increase your electric usage and carbon footprint.
  2. You are reheating the same water over and over again, which also increases energy usage.
  3. You have another device in the house that will eventually break.

Recommendations if you decide to go forward

  • Water heater location. If you are building new or remodeling and have access to pipes, consider locating the water heater as close as possible to the showers. If the hot water to the dishwasher or clothes washer is cold, it still gets used. People will even rinse hands in a half-bath with cold water. People won't typically take a cold shower, though.
  • PEX piping. At a minimum, use PEX piping if allowed by code, as it is a natural insulator, or insulate the hot water supply pipes.
  • Use a timer. Install a recirculation pump with a timer that you set for the morning shower time only. I have also seen instances where a recirculation pump is located in the bathroom under the sink and is on a wall switch. When you get up in the morning you turn on the switch, and by time you hit the shower it is hot.
  • Get an energy efficient pump. There are newer recirculation pumps on the market that use one-fourth the energy of the standard ones on the market, so do your homework.

Hope this helps.

 

For more information:

Check our hot water recirculating Q&A to see what other homeowners and contractors are saying about passive vs active recirculation, timers, etc."

Tagged In: green plumbing, hot water recirculating

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