AN-92-11-4 -- Free Cooling Works for Cowlitz County Hall of Justice PDF

The Cowlitz County Hall of Justice has been converted to a well-source heat pump system with indirect well water cooling. This system reduced energy use by 22% the first year it was installed. These savings are achieved by using well water for "free cooling" during the summer. During the remainder of the year, the well provides the needed heating or cooling energy for the heat pump, which transfers heat from the areas of the building needing cooling to those needing heating. Several problems have been encountered with the system. The wells had unanticipated iron bacteria fouling. The wells need cleaning regularly. The heat exchangers need more room for cleaning and should have been designed with more generous fouling factors. Performance loss of equipment was not taken into account. Despite the problems, the system provides energy savings and better building comfort.

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