Completion / After · Repair · Hotel
Indian Wells, CA 92210
A Hotel client of ours called us in for a major repair and performance issue on a large 100% outside-air HVAC system built to condition some of the toughest desert air imaginable. We replaced a failed compressor VFD and installed a new like-for-like PENN System 450 pressure controller. Instead of simply swapping parts, we documented the original programming, duplicated every control parameter, verified the new VFD’s motor data and 0–10V control strategy, and commissioned Compressor #1 at a temporary 50 Hz limit while monitoring amperage, kW, pressures, superheat, subcooling and discharge temperature. The evaporator was also heavily impacted with dirt deep inside the thick coil. We performed a multi-stage cleaning process: soft wash to wet and loosen contamination, appropriate coil-cleaning chemical to break down embedded buildup, then controlled pressure washing from both sides. This entire process was repeated four times. The amount of mud removed was substantial—heavy debris accumulated in the drain pan and flushed through the condensate system. On the water side, supply and return screens were serviced and the condenser-water circuit was backflushed multiple times to clear accumulated debris and improve heat transfer. At 50 Hz, Compressor #1 stabilized around 14.7 amps / 8.26 kW while we logged refrigerant saturation temperatures, compression ratio, superheat, subcooling and water temperatures. With both refrigeration circuits operating, this 100% outdoor-air unit produced approximately an 18.7°F air-temperature reduction—taking roughly 89.3°F incoming outdoor air down to 70.6°F supply air. We also identified additional control-sequence and refrigerant-feed conditions that require further investigation rather than guessing or blindly adding refrigerant. Commercial HVAC isn’t just “cold air.” It’s electrical engineering, refrigeration physics, airflow, water flow and controls all working together—and every number tells part of the story.
Field Photos
Progress
Technician: Frank K