Method of Test for Field Performance of Liquid-Chilling Systems

Abstract

ASHRAE Standard 184 was published in 2016 and prescribes methods of testing to measure performance, such as capacity and efficiency, of liquid-chilling systems as installed in the field within a building system.

A key concept of the testing process is to conduct an analysis to estimate the uncertainty of both measurements and the results calculated from those measurements.

This analysis process starts during the planning phase while preparing for the test (pretest estimate of uncertainty) and finishes after the test is conducted (posttest estimate of uncertainty).

The standard refers users to ASME PTC 19.1, Test Uncertainty, for the uncertainty analysis methods.

This addendum to the standard provides additional guidance on conducting this analysis by adding two informative appendices to the standard.

One includes a spreadsheetbased calculator that guides the user through the calculations but continues to rely on some level of expertise in providing the input data and making engineering judgments about the test setup to quantify the uncertainty with reasonable estimates.

On that point, the second new appendix provides examples of typical measurement instruments, their specifications and technical information, and how to extract and interpret the information to create the inputs to the uncertainty calculations.

Note: In this addendum, changes to the current standard are indicated in the text by underlining (for additions) and strikethrough (for deletions) unless the instructions specifically mention some other means of indicating the changes.