ET23SWE0025 - Water-Cooled Chillers Market Assessment & Performance Evaluation

The current measure package for Water-Cooled Chillers (WCC) has several shortcomings that have been identified, most notably an unrealistic full-load efficiency (FLE, in kW/ton) requirement to go along with the part-load efficiency (PLE, in IPLV) requirement. Current WCC measures are restrictive in that they require 10% above-code efficiency for both full & part-load ratings, while most equipment is optimized for one or the other metric. Therefore, having accurate technical performance in the existing measure is crucial to seeing any energy savings in this measure. This issue was studied in-depth in 2019 and 2020, culminating in collecting 25 WCC performance maps and efficiency rating pairings (i.e., FLE and PLE scores) for dozens of additional chillers to show where the market is regarding WCC efficiency trends. The data was presented to CPUC which resulted in the less restrictive FLE requirements in E-5152. However, these new policies have not been incorporated into SWHC005 (or a new standalone measure package) yet, which is the main but plans for updating and fixing the measure package have not been completed. The measure package does not accurately reflect performance, particularly at part-load conditions. Not all requirements of CPUC Resolution E-5152 for more accurate modeling have been incorporated into the current measure package. Current WCC measures are restrictive in that they require 10% above-code efficiency for both full & part-load ratings, while most equipment is optimized for one or the other metric, so having accurate technical performance in the existing measure is crucial to seeing any energy savings in this measure.

While our overall goal is to deliver the “new standalone measure package (SWHC005) in the CA eTRM”, the measure package can only be completed and delivered in 2024 after the CPUC has moved their modeling engine from DOE-2 to EnergyPlus, and the transition effort should be completed by the end of 2023. The team will, therefore, undertake a study in 2023 with the following supplementary tasks:

• Investigate whether the data works with the Low-GWP refrigerants by working with manufacturers,
• Collect performance maps for heat recovery chillers this year from manufacturers and/or distributors,
• Ascertain that the previously collected technical performance 2019 WCC data can be modeled in EnergyPlus, and
• Write a measure package plan this year for CPUC consideration and feedback for potential execution in 2024.

This project will leverage previously collected technical performance data, completing an effort begun in 2019, that can be used to update measure package (SWHC005) in the CA eTRM in 2024.