REFRIGERATION EQUIPMENT CERTIFICATION
ISSUE:
The new ARI (Air -Conditioning and Refrigeration Institute) Standard 550/590 98
for water chilling packages using the vapor compression cycle.
BACKGROUND:
The newly published ARI Standard 550/59098 combines two previously separate
standards, ARI Standard 550-92 for Centrifugal and Rotary Screw Water Chilling
Packages, and ARI Standard 590-92 for Positive Displacement Compressor
Water Chilling Packages. The new standard reflects several important changes
regarding how chillers are rated and tested.
DISCUSSION:
The two major changes are in regard to the integrated part load value (IPLV), and
the fouling factor adjustments used for evaporators in closed loop water systems
such as chilled water systems. The IPLV rating conditions and part load
weightings are changed to more closely reflect actual operating experience found
in the field for a single chiller. The evaporator fouling factor is changed from
0.00025 to 0.0001 based on research sponsored by ASHRAE (American Society
of Heating, Refrigerating, and Air- Conditioning Engineers).
Also, application part load value (APLV) has been replaced with non-standard part
load value (NPLV), and should be used when a chiller is not intended to operate at
standard ARI conditions.
RECOMMENDATIONS:
1. Follow new ARI Standard 550/590-98 on future projects. Manufacturers
published performance and computer-rating programs will reflect this new
performance.
2. VA Master Construction Specification Section 15650, Refrigeration
Equipment (HVAC) has been updated.
3. With ARI certified chillers no field testing of equipment is required for
performance and capacity. However, chillers need to be tested in the field for
proper and safe operation of the equipment.
FOR ADDITIONAL INFOR MATION:
Contact Satish Sehgal at 202-565-5032 in the Facilities Quality Service (181A).
9 March 1999
FM-181A-DA97
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