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ENERGY PERFORMANCE ASSESSMENT OF HVAC SYSTEMS

Purpose of the Performance Test:

Estimate the energy consumption at actual load vis-a-vis design conditions.

Performance Terms and Definitions

TR

The amount of cooling obtained by one ton of ice melting in one day:

3024 kCal/h

12,000 Btu/h

3.516 thermal kW.

Performance Terms and Definitions

Net Refrigerating Capacity

Mass flow rate of the evaporator water multiplied by the difference in enthalpy of water entering and leaving the cooler, expressed in:

kcal/h

TR

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Test readings should be taken as nearly simultaneously.

Performance Terms and Definitions

kW/ton Rating

Referred to as efficiency, but actually power input to compressor motor divided by tons of cooling produced (kW/ton). Lower kW/ton indicates higher efficiency.

Performance Terms and Definitions

COP

Chiller efficiency measured in (cooling load) divided by input (electric power).

Performance Terms and Definitions

Energy Efficiency Ratio (EER):

The higher the EER, the more efficient the unit.

Smaller chillers Chiller's cooling capacity (in Btu/h) / Power input (in watts) The higher the EER, the more efficient the unit.

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The accurate temperature measurement is very vital in refrigeration and air conditioning and least count should be at least one decimal.

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Power (kW) = 3 x V x I x cos

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The energy efficiency of a chiller is expressed in :

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Evaporator a. Temperature of water entering evaporator b. Temperature of water leaving evaporator c. Chilled water flow rates d. Evaporator water pressure drop Compressor

Compressor electrical power, kW