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