Salt Lake saves eight tons of CO2 with the warmth of sewage

Photo by Graham Murdoch

Case Study: Heating Homes from Waste

"When Salt Lake City attorneys Jon and Phillip Lear decided to set up offices in the Major George Downey mansion downtown in 2005, gas prices had spiked after Hurricane Katrina, and they started brainstorming alternative heating and cooling systems.

'Alternative' is the word for what the brothers came up with. The system they designed, with help from engineers at Utah’s Sound Geothermal Corporation, pulls heat from warm sewage water. A secondary network of pipes surrounding a sewage pipe carries a water-based glycol that enables a heat exchange—since it is cool relative to the sewage water, it rapidly absorbs heat. The pipes carry the warmed glycol back into the house, where the accumulated heat energy radiates from vents. On hot summer days, the glycol absorbs heat from inside the house and releases it underground. The entire setup uses about 40 percent less energy than a conventional heating and cooling system would, reducing carbon dioxide emissions by eight tons a year. The Lears moved their offices there permanently in January.

Public-utilities director Jeff Niermeyer hopes to install similar systems in other public buildings within the next few years. 'With any wastewater system, there’s a lot of heat that you’ve already put in for other purposes,' he says." (Popular Science Case Study)

For more information, see also the Deseret News article on this home which speaks of the potential to use this technology on the City Creek Center in Salt Lake.