Update on Chiller Efficiencies

UPDATE ON CHILLER EFFICIENCIES

ISSUE:

Improved chiller efficiencies offered by major chiller manufacturers.

DISCUSSION:

Present VA criteria calls for 0.62 kW/ton for full and part load efficiencies, and the

Design Alert 38 dated June 21, 1995, listed these efficiencies offered by various

manufacturers. Since then, further improvements have taken place. For example,

General Services Administration (GSA) has a Basic Ordering Agreement (BOA)

and all major manufacturers are committed to provide following efficiencies:

Product Type

Full Load Efficiency

Part Load Efficiency

(kW/ton)

Centrifugal Chillers up to

0.60

0.56

1600 tons

Rotary Screw Chillers

0.65

0.59

175 tons and larger

Above part load efficiencies are based on ARI standard 550-92, IPLV (Integrated

Part Load Value) standard ARI conditions.

RECOMMENDATIONS/CONCLUSION:

1. Some manufacturers can provide better efficiencies than stated above, but

requiring higher efficiencies would limit competition.

2. BOA agreement allows an equal to or better than either the full load or IPLV

efficiencies listed in the table.

3. VA criteria for chillers is being improved requiring consultants to meet a goal of

0.60 kW/ton for full load and 0.56 kW/ton for part load efficiencies.

16 October 1997

FM-187C-DA70

Index