Arizona homeowners fight drought conditions with demand-controlled pumps

Arizona homeowners fight drought conditions with demand-controlled pumps

In Sierra Vista, Ariz., results from an experiment to save water in the drought stricken region using demand-controlled pumps show that homeowners can save water with one simple device.

The Cochise Water Project (TCWP) is a non-profit 501c3 serving the Sierra Vista sub watershed with a sole purpose of reducing water drawn from its aquifer.


The first ACT D'MAND Kontrols "Model C" pump installed in the Sierra Vista area under the auspices of the TCWP grant rebate program.

During 2013, via a grant rebate program, TCWP installed more than 130-demand-controlled pumps (DCP) as one of its wasted-water reduction programs throughout the sub watershed.

Dave Grieshop, managing partner of Reality LLC, a consultant on the project, worked with homeowners who had installed a DCP to record how much water and time they spent waiting for hot water.

Grieshop wanted to understand how much water and time homeowners wasted at the kitchen sink and at a shower or sink in the master bathroom when using their DCP and not using their DCP.

Larry Acker, CEO of ACT Inc. D'MAND KONTROLS® Systems, talks about using DCPs to reduce water and energy waste in homes.

The homeowners were more than willing to help because earlier TCWP survey results regarding DCPs showed everyone was delighted with their installations. Wasted water was defined as "the water down the drain waiting for the water to get hot enough so one could shower."

Eleven sets of data were collected. Then a daily hot water demand scenario was constructed. Each homeowner was assumed to make three hot water demands at the kitchen sink and one hot water demand in the master bathroom. These four daily demands resulted in a weighed average demand for each home in terms of wasted water and wasted time with and without the DCP.

This was done for two reasons. "First, four daily hot water demands is substantially below what the literature indicates," Greishop said. "Secondly, it negated the number of home occupants. The data was behavioral not scientific; it was real data."

Grieshop noted that one homeowner collected six sets of data so they could get a sense of the average cups and seconds involved as well as the standard deviation for the cups and time data.

"Surprisingly, the standard deviation was quite 'tight,' in other words, there was not an unreasonable amount of variability," Grieshop said. "Also, two homeowners voluntarily gave me 3 sets of data; again, the variability was surprisingly 'tight.'"

The homeowners who provided the data all lived in single-story homes ranging in age from almost 100 years old to a less than 2-year-old home, which was LEED Platinum certified. Home sizes ranged from 2150 to almost 4000 square feet.

The LEED platinum home during construction, which incorporates three demand controlled pumps, and the average wasted water while waiting for hot water is less than 0.5 cups per demand when the home was finished.

The results from the homes were startling. About 2,800 gallons of water were wasted without the DCP versus 230 gallons while using the device. The data showed that without using the DCP, the water usage among the 11 homes was highly variable.

Each home wasted more than 26 hours per year waiting for hot water without the DCP compared to slightly more than two hours using the DCP.

"Homeowners wasted more than a day per year waiting for hot water without a DCP," Grieshop said. "No wonder the local homeowners consistently said it was the convenience they liked most about the DCP in their homes."

Read more about water-saving devices.

[Photo courtesy of Kohler]

Topics: Bathroom, Kitchen, Plumbing & Fixtures, Water Heaters, Water Saving Devices, WaterSense

Companies: ACT D'MAND Systems

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