Energy Efficiency Reference/Refrigeration/Recommendations/Install ASD on Evaporator Fans

Recommendation: Install ASD on Evaporator Fans
Summary: Convert fan motors to adjustable speed drives (ASD's) on air-cooled evaporators to reduce part-load fan power.

When to apply: When single-speed or two-speed fan motors demand a lot of power.

Key Engineering Concepts:


 * Ideally, fan power is cubically related to fan capacity with a variable speed motor
 * Fan power is linearly related to capacity with on-off fan control
 * Fan capacity is proportional to the condensing approach temperature difference

Preparation:

Tools required


 * DMM or power analyzer
 * Clamp-on Ammeter
 * Stopwatch
 * Thermometer
 * Refrigeration Data Sheets

Data Sheet


 * Suction Temperature (ST)- from pressure gauge or compressor display
 * Total fan power (FP) - measured
 * Dry bulb temperature - measured
 * Evaporator approach temperature difference (DT, approximately 10 degree F) - measured
 * Fan cycling schedule, if any.

Analysis Process: ?????