Alberta Hospital Cooling System Curbs Energy Costs

Alberta Hospital Cooling System Curbs Energy Costs

System Identification: HVAC chilled water system

Solids/Liquids: Metallic oxide grit, scale, sand, grit, and water

Problems: Fouling from both internal and external forces reduced the efficiency of the cooling system at the 600-bed University of Alberta Hospital site in Canada. Manufacturer’s data for the coils connected to this system documents an increase in overall system energy consumption by 7% for a fouling factor of only .001. The efficiency of any cooling system can be increased by controlling the accumulation of solids. As the largest user in a district cooling system, the hospital receives water that travels through more than two kilometers of piping from the central location. The hospital gathers deposits of scale and other particulates from other areas and buildings on the system. Even in this closed-loop system, the piping was becoming sufficiently obstructed and causing a significant impact on energy consumption, demanding the need for an effective filtration solution.

Solution: To clean up the piping systems serving the hospital, LAKOS Separators with Closed Recovery Systems were installed in a side-stream application on both of the chilled water systems. With flows ranging from 480-880 US GPM (110-200 m³/hr) depending on the season (the system operates in two distinct modes). The installed separators are removing significant amounts of solids, with marked gains in energy efficiency. Independent testing identified removed solids ranged in size from 2 to 630 microns. Doug Dunn, Manager of Building Operations, conservatively estimates on 8% reduction in energy costs, saving the facility over $20,000 annually. He expects payback on the units to be achieved in about two and a half years. The LAKOS Closed Recovery System promotes zero liquid loss and easy disposal of solids, saving valuable water resources and money. Additional benefits not calculated include reduced wear and maintenance to system pumps. Integral to the success of this retrofit was the simplicity of the installation, and the relatively small footprint of the LAKOS Separator and Closed Recovery System. Performance of a single LAKOS filtration system in the first phase was so successful that the second phase was accelerated, and other facilities within the district have taken note of the success. Additional projects are now underway in other facilities on the district cooling system.

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