Hospitals contain diverse, demanding environments that require dependable cooling system equipment performance. Operating rooms, critical care facilities, data centers, imaging centers -- plus worker productivity -- all are to some extent dependent on the reliable operation of the HVAC system, particularly in warm weather.

To overcome recurring cooling tower-related comfort cooling performance problems, Davis Memorial purchased two new cooling towers to support its two 300-ton Carrier chillers. Like the owners of many industrial, business and institutional buildings, the hospital management was looking for a more advanced cooling tower technology that would optimize performance while minimizing maintenance requirements.

Research led the hospital’s Steven Johnson, director of support services, to select cooling towers with a seamless plastic shell. “The one [cooling tower] that attracted my attention was a line that was made of high-density polyethylene (HDPE), Of course, there were a lot of other models available, but most of them seemed to be the metal-clad design.”

The all-plastic cooling towers, manufactured by Delta Cooling Towers in Rockaway, N.J., have HDPE cooling tower shells that are virtually impermeable to corrosive elements, including water treatment chemicals such as chlorine, as well as UV rays.

And, while the avoidance of downtime and the need for unscheduled cooling tower maintenance were critical requirements for Davis Memorial Hospital, there were other features of the Delta design that also had value.

“The variable-speed, direct-drive motors that run the fans on our new towers also provide unexpected benefits,” Johnson says. “First of all, these drives are far more efficient than we initially realized. The fan motors on our old towers were 30 horsepower each, and consumed considerably more energy than the new ones which are only seven horsepower each, and at least 50 percent more energy efficient.”

With no belts, shafts, bearings or other external parts to service, the direct-drive motors are nearly maintenance free.