The unknown power of circulation pumps

Written in collaboration with Ashley Leung.

Who consumes more electricity: wash your hands or feed your refrigerator? This could be the first in many places – surprisingly, some of the biggest consumers of energy in our buildings are the pumps that circulate hot water. In fact, many of them more than double the amount of energy used to heat that water in the first place and use twice as much electricity as two typical refrigerators, according to search for energy Solutions.

Hot circulating water pumps are powerful for water conservation, saving up to 1000 gallons per person per year. Without these pumps, someone would usually have to let their faucet run for a while and wait for the hot water from the radiator to flow through the pipes – this means a large amount of otherwise usable cold water flows directly into the sewer. . Circulating pumps move hot water through pipes around the building so that it is ready for use faster, reducing the need to run the faucet and thus saving a lot of water, time and money .

Not all Pumps are created equal

TThe most common circulation pumps run all day, every day, whether you are actively using hot water or not. This causes a large amount of heat to dissipate in the pipes 24/7, and the water heater has to work twice as hard to keep the water hot. And running the pump continuously also consumes a lot of electricity, in fact more than two typical refrigerators on an annual basis, according to a recent study. Energy Solutions report. The combined use of energy for water heating and pump operation makes these circulators one of the biggest consumers of energy in the homes and buildings that use them.

Some circulation pumps use a timer which can be programmed to only run the pump at certain times of the day, but these still typically run 12-16 hours a day, so these are only marginal improvements. Fortunately, we have other much more efficient models that save so much water while using only a small fraction of the energy. These options can, for example, pump on demand when hot water is needed or use other advanced control solutions in large apartment buildings.

These smarter circulators would save you more money on your energy bill, to add to the savings on the water bill. In fact, these energy and water savings pay off the cost of the pumps in 2 to 6 years, according to Energy Solutions – that’s a lot given that circulating pumps can last for decades.

In addition, continuously and timer pumps are a barrier to moving away from fossil fuels for domestic water heating, as they cause heat pump water heater, the alternative specific to gas water heaters, to operate in inefficient electrical resistance mode much more frequently than they typically do. As part of their electrification efforts, utilities and states across the country are looking to install more heat pump water heaters in buildings via incentives and building codes. Continuous and timed pumps are a hindrance to these efforts as they have to be replaced when installing a heat pump water heater, increasing the cost of the conversion.

The Circulation pump policies

The Department of Energy (DOE) worked since 2016 To develop an energy efficiency standard for hot water circulation pumps. However, this effort is only on a small part of the energy- savings and decarbonisation opportunity. Making the motor more efficient only saves a limited fraction of their energy consumption.

The great opportunity for energy and carbon savings lies in the shift from continuous and timer controlled pumps to demand control strategies and other advanced strategies. These can save nearly 90% of electric power, more than half of the energy for heating water, and remove a barrier to cost-effective electrification of water heating, according to Energy Solutions. And this is the kind of transformative opportunity we must seize if we are serious about reducing energy waste, reducing emissions and avoiding the climate crisis.

A die promising policies for the transition from unnecessary conventional circulation pumps to smart and efficient alternatives, is done through flexible on-demand device standards that California initiated with Senate bill (SB) 49 in 2019. These standards are relevant for circulation pumps because these pumps are particularly suited to the use of controls to steer demand away from peak periods of electrical demand, while reducing pollution from reduced gas combustion.

A die The biggest standard opportunities

The implementation of a The standard under authority SB 49 for demand control solutions or other advanced control solutions for domestic hot water circulation pumps would save a lot of electricity for pump operation and gas for water heating. Researchers find this, by 2030, it could save Californians 5 million tonnes of CO2 and 7 terawatt hours of electricity (equivalent to 1 million cars on the road for one year). It would also reduce 500 to 800 million therms of methane (by taking another 500,000 to 800,000 off-road cars for one year). This standard would be one of the most important and cost-effective appliance standard opportunities to help achieve the AB 3232 target of reducing emissions associated with energy use in buildings by 40% d ‘by 2030.

Intelligent and efficientt Circulators for all

On-demand commands work well for single-family homes. For large apartment buildings with central hot water systems, where circulation pumps are prevalent due to longer pipe lengths and wait times for hot water, more advanced control solutions are available. required, such as thermally balanced variable speed pumps. These applications are particularly important from an equity perspective because a disproportionate share of low income households live in apartments or inefficient circulation pumps contribute significantly to their energy load.

In addition to higher relative costs of wasted energy, low-income households are often less able to access the benefits of newer and more efficient products that save money for those who can afford the upfront costs . These are often tenants who have no control over the choice of equipment such as circulation pumps. Standards are one of the best ways to ensure that low-income households are not left behind and have equitable access to the benefits of energy efficiency and decarbonisation.

Save money and the planet

Increasing energy efficiency and reducing climate pollution through technologies such as smart and efficient circulation pumps help us to better integrate renewables into the grid and may even lower the cost of electricity. They can save us money on utility bills while paying themselves the savings, conserving energy and water, reducing emissions and decarbonizing our buildings in the face of the climate crisis. Our decision-makers must combine policy levers such as the SB 49 with technological solutions such as efficient hot water recirculation pumps to set us on the ambitious but necessary path to meet science-based climate goals and preserve a liveable planet. .

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