What is COP, IPLV, NPLV & SPLV in Air Conditioner System

What is COP, IPLV, NPLV & SPLV in Air Conditioner System
COP or Coefficient of performance is the key performance evaluation parameter of any air conditioning system. It is the ratio of cooling energy output for the amount of work done. Higher the value of COP higher is the performance and lower the power consumption. COP value can define the performance of the AC system at full load conditions and this value cannot be used to assess the exact performance of the system at the actual operating conditions that too project specific. Hence to assess the performance at part load conditions different terms like IPLV, NPLV & SPLV are used: 

Integrated Part Load Value (IPLV) :

Generally, the performance value, COP of an air conditioning machine is derived considering 100% loading. But most of the air conditioners run at design load only at 1% of its lifetime. Hence to calculate the exact performance value considering different loading conditions, IPLV is used.

IPLV is derived considering weighted average of 4 loading points (25%,50%,75%&100%) – most appropriate reference

IPLV = 0.01A+0.42B+0.45C+0.12D; where A,B,C & D are the COP values at 4 loading points respectively.

(COP values are calculated using flow rates, entering and leaving water temperatures of evaporator and condenser)

Net part-load value (NPLV):

Net Part load value is also used to assess the performance of the air conditioning system at part load conditions. The formula for calculating the IPLV and NPLV is same as above. The difference between IPLV and NPLV is that the values A.B, C.D are calculated based on standard values specified by AHRI for IPLV and are calculated based on desired values for NPLV. Please refer to the below table on  IPLV vs NPLV.

NPLV Chart

Specific or System Part Load Value (SPLV):

SPLV is a project-specific, single number, part-load efficiency indicator introduced by Carrier that is calculated using the equation form defined in ARI 550/590- 1998. Unlike IPLV or NPLV, the factors used to calculate SPLV are project-specific and consider multiple chiller applications, actual operating hours, and project-specific operating conditions.

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