John Koeller

John Koeller is a registered professional engineer with extensive experience in water-efficient technologies and products. Widely recognized as a water efficiency specialist, Koeller is a consultant to numerous water providers, green-building organizations, and private-sector firms. He is codeveloper of Maximum Performance (MaP) testing for toilet fixtures.

Articles By Author

The Real High-Efficiency Toilets Have Arrived

Author: John Koeller
June 07, 2007

Why discuss toilets in an energy publication? The interesting secret about toilets—and all of the other fixtures and appliances that use water—is that they are responsible for a good part of ... [continue reading]


Danger in the Shower: 2008 Forum Looks at Hot Water

Author: John Koeller
January 02, 2009

On average, water heating accounts for 15% of residential energy consumption. In the past few years, there has been an explosion of interest in meeting domestic hot water needs more efficiently. New hot-water-generating technologies, structured plumbing ... [continue reading]


Does Replacing Toilet Fixtures Save Water?

Author: John Koeller
January 03, 2012

Koeller and Company studied the water savings achieved with toilet fixture replacements in an urban apartment complex. [continue reading]

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