Centrifugal Machines
ASHRAE Technical Committee 8.2

Scope of TC 8.2

TC 8.2 is concerned with packaged equipment which involves centrifugal compressors, including those heat exchangers, drivers, controls and accessories, which are specific to packaged centrifugal equipment. TC 8.2 is also concerned with the design and performance of centrifugal compressors, steam turbines and gas turbines for use in refrigerating applications.


The ASHRAE Handbook is published in a series of four volumes, one of which is revised each year, ensuring that no volume is older than four years.

TC 8.2, along with TC 8.1, is responsible for the following handbook chapters:

HVAC Systems and Equipment: Compressors
A compressor is one of the four essential components of the basic vapor compression refrigeration system; the others are the condenser, evaporator, and expansion device. The compressor circulates refrigerant through the system and increases refrigerant vapor pressure to create the pressure differential between the condenser and evaporator. This chapter describes the design features of several categories of commercially available refrigerant compressors.

HVAC Systems and Equipment: Liquid Chilling
Liquid-chilling systems cool water, brine, or other secondary coolant for air conditioning or refrigeration. The system may be either factory-assembled and wired or shipped in sections for erection in the field. The most frequent application is water chilling for air conditioning, although brine cooling for low-temperature refrigeration and chilling fluids in industrial processes are also common. The basic components of a vapor-compression, liquid-chilling system include a compressor, liquid cooler (evaporator), con-denser, compressor drive, liquid-refrigerant expansion or flow-control device, and control center; it may also include a receiver, economizer, expansion turbine, and/or subcooler. In addition, auxiliary components may be used, such as a lubricant cooler, lubricant separator, lubricant-return device, purge unit, lubricant pump, refrigerant transfer unit, refrigerant vents, and/or additional control valves.

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Technical committees develop and sponsor technical sessions at the winter and annual conferences. Information about their future technical program is discussed at each TC meeting and at the TC’s Program Subcommittee meeting

ASHRAE publishes papers and transactions from presentations at its conference events. In addition, ASHRAE records most of the seminar sessions from its conferences on DVD. These DVDs are ideal for use at chapter meetings, in university courses, or company lunch and learns. Products available from the most recent conference may be found here.

TC 8.2 sponsored the following technical sessions at the Las Vegas 2022 meeting:

High Efficiency Variable Speed Pumping Systems and Integration Challenges with Chiller Plant Design

Chair: Trent Hunt, Member, Mechanical Products NSW, Salt Lake City, UT

This session overviews variable speed chilled water pumping systems with a technical understanding of how a chiller fits into primary-secondary, variable primary and distributed-variable primary systems. The purpose of this seminar is to present the technical points of each type of pumping system in terms of function and operation while providing an understanding of how a water chiller responds functionally to a variable fluid flow through its evaporator. Presenters provide pointers and suggestions in the form of lessons learned regarding the control and operation of each of these systems.

1. Key Chiller Selection Criteria in a Variable Flow Pumping System
   Rick Heiden, Member, Trane, La Crosse, WI
2. Pumps That Know the Flow in Chilled Water Pumping Systems
   David Lee, P.Eng., Member, Armstrong Fluid Technology, Toronto, ON, Canada
3. Lessons Learned in Control and Operation of Primary-Secondary and Distributed Pumping Chilled Water Systems
Chris Miller, P.E., Member, P2S, Inc., Long Beach, CA
4. Key Design Considerations for the Implementation of Variable Primary Chilled Water Pumping Systems
Brandon Gill, P.E., Member, Taylor Engineers, Alameda, CA


Reduced Order Modeling for HVAC&R Systems and their Components

Chair: Alex Schmig, Member, Trane, La Crosse, WI

This seminar will focus on methods and advantages of simplifying physical analytical models to reduced order models that can be implemented and adapted for use in system models or for standalone analysis. Presenters focus on differing approaches to reduce modeling complexity and decrease computational intensity. Topics explore modulation and extrapolation of reduced order compressor models, uncertainty propagation, adaptability to new low-GWP refrigerants, simulated cycle modeling and validation of reduced order models.

Application of Data-Driven Models for Positive Displacement Compressor Mapping
    Davide Ziviani, Ph.D., Member, Purdue University, West Lafayette, IN
2. Semi-Empirical Compressor Model Evaluation Considering Modulation and Extrapolation Performance
    Kalen Gabel, Student Member, Center for Integrated Building Systems, Oklahoma State University, Stillwater, OK
3. Reduced-Order Modeling and Fast Simulation of Transient Vapor Compression Cycles
   Jiacheng Ma, Student Member, Purdue University, West Lafayette, IN


Design Challenges to the Electrification of Heating in Mid to Large Buildings

Chair: Raymond Good Jr., P.E., Member, Danfoss Turbocor Compressors, Inc., Tallahassee, FL

Electrification of heating is becoming an imperative based on a desire to reduce heating with fossil fuels and in some cases to meet codes and standards enacted to reduce greenhouse gas emissions. This seminar introduces some of the basic concepts and driving forces behind the current and developing trend of electrified heating. It also explores some of the technologies available and share specific design and control strategies that make the dream a reality.

1. Fundamentals and Technologies of Heating Electrification
   Trent Hunt, Member1 and Drew Turner2, (1)Mechanical Products NSW, Salt Lake City, UT, (2)Danfoss, Baltimore, MD
2. Time Independent Energy Recovery: The Solution to Large Building Electrification
    Brandon Gill, P.E., Member, Taylor Engineers, Alameda, CA
3. The Ins and Outs of Heat Recovery Chiller Sizing and Control
    Chris Miller, P.E., Member, P2S, Inc., Long Beach, CA



Technical Committees are responsible for identifying research topics, proposing research projects, selecting bidders, and monitoring research projects funded by ASHRAE. Information about their specific research program is discussed at each TC meeting and at the TC’s Research Subcommittee meeting.


 ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry. ASHRAE publishes the following three types of voluntary consensus standards: Method of Measurement or Test (MOT), Standard Design and Standard Practice. ASHRAE does not write rating standards unless a suitable rating standard will not otherwise be available. ASHRAE is accredited by the American National Standards Institute (ANSI) and follows ANSI's requirements for due process and standards development. Standards may be purchased at the ASHRAE Bookstore.

TC 8.2 is cognizant for the following standards:
Std. 30: Method of Testing Liquid Chilling Packages
SPC -184P: Proposed standard - Method of Test for Field Testing of Liquid-Chilling Systems

TC 8.2 is co-cognizant for the following guideline:
GDL-22: Instrumentation for Monitoring Central Chilled Plant Efficiency

Other Activities

TIP: If MTG involvement add here otherwise leave blank.

TC 8.2 participates in the multidisciplinary task group, MTG.LowGWP.

Lower Global Warming Potential Alternative Refrigerants
MTG.LowGWP is established to coordinate TC/TG/TRG technical activities to help transition the HVAC&R industry to sustainable lower Global Warming Potential (GWP) alternative refrigerants. The MTG will further request participation from US EPA and AHRI. The MTG responsibilities include suggestions for research, development and presentation of technical programs of all types on alternative lower GWP refrigerants, suggestions for Life Cycle Climate Performance (LCCP) systems evaluation for different applications, development of lower GWP solutions for different applications, and a special publication detailing aspects of LCCP applied to the HVAC&R fields. 


ASHRAE Technical FAQs are provided as a service to ASHRAE members, users of ASHRAE publications, and the general public. While every effort has been made to ensure their accuracy and reliability, they are advisory and provided for informational purposes only, and in many cases represent only one person’s view. They are not intended and should not be relied on as an official statement of ASHRAE. Technical questions not addressed may be submitted to the ASHRAE Technical Services department at tse@ashrae.net.