Positive Displacement Compressors
ASHRAE Technical Committee 8.1

Scope of TC 8.1

TC 8.1 is concerned with the design, performance, features, and operating characteristics of all types of positive displacement compressors for use with refrigerants.


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TC8.1 is responsible for this chapter in the ASHRAE REFRIGERATION Handbook:

Factory Dehydrating, Charging, and Testing
Proper dehydration, charging, and testing of packaged refrigeration systems and components (compressors, evaporators, and condensing coils) help ensure proper performance and extend the life of refrigeration systems. This chapter covers the methods used to perform these functions. It does not address criteria such as allowable moisture content, refrigerant quantity, and performance, which are specific to each machine.

TC 8.1 is responsible for these chapters in the ASHRAE HVAC SYSTEMS AND EQUIPMENT Handbook

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. For information on absorption equipment, see ASHRAE Handbook—Refrigeration.

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.

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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 8.1 is cognizant  for the Following Standards:

Standard 23.1: Methods of Testing for Performance Rating Positive Displacement Refrigerant Compressors and Condensing Units That Operate at Subcritical Pressures of the Refrigerant
ANSI/ASHRAE Standard 23.2: Method of Test for Rating the Performance of Positive Displacement Compressors that Operate at Supercritical Pressures of the Refrigerants

TC 8.1 is co-cognizant with TCs 1.2 (lead) and TC1.1 for these standards:

ASHRAE Standard 41.1: Standard Methods for Temperature Measurement
ASHRAE Standard 41.2: Standard Methods for Laboratory Air-Flow Measurement
ANSI/ASHRAE Standard 41.3: Standard Methods for Pressure Measurement
ANSI/ASHRAE Standard 41.4: Standard Methods for Proportion of Lubricant in Liquid Refrigerant Measurement
ANSI/ASHRAE Standard 41.6: Standard Methods for Humidity Measurement
ANSI/ASHRAE Standard 41.7: Method of Test for Measurement of Flow of Gas
ASHRAE 41.8: Standard Methods of Measurement of Flow of Liquids in Pipes Using Orifice Flowmeters ANSI/ASHRAE Standard 41.9: Standard Methods for Volatile-Refrigerant Mass Flow Measurements Using Calorimeters

ANSI/ASHRAE Standard 41.10: Standard Methods for Refrigerant Mass Flow Measurement Using Flowmeters
ANSI/ASHRAE Standard 41.11: Standard Methods for Power Measurement

Other Activities

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Include other activities, such as MTG involvement, into this section.


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