Custom Engineered Refrigeration Systems
ASHRAE Technical Committee 10.1

Scope of TC 10.1

TC 10.1 is concerned with one of a kind industrial applications of standard or special equipment to meet specific refrigeration requirements.


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.  The ASHRAE Handbooks may be purchased from the on-line bookstore through the highlighted link.

TC 10.1 is responsible for the following chapters in the Refrigeration Handbook:

Refrigeration: Liquid Overfeed Systems

Overfeed systems force liquid in excess of the amount evaporated, either mechanically or by gas pressure, through organized-flow evaporators, separate it from the vapor, and return it to the evaporators. Mechanically pumped systems usually pump from a vessel at the connected suction pressure (i.e., low-temperature liquid). Gas-operated systems can be configured to deliver either low-temperature liquid directly like the mechanically pumped system, or sub-cooled liquid from a controlled pressure receiver at an intermediate pressure. With the latter, the accumulated overfed liquid is transferred from the low-pressure receiver back to the controlled-pressure receiver.

Refrigeration: Component Balancing in Refrigeration Systems

This chapter describes methods and components used in balancing a primary refrigeration system. A refrigerant is a fluid used for heat transfer in a refrigeration system. The fluid absorbs heat at a low temperature and pressure and transfers heat at a higher temperature and pressure. Heat transfer can involve either a complete or partial change of state in the case of a primary refrigerant. Energy transfer is a function of the heat transfer coefficients; temperature differences; and amount, type, and configuration of the heat transfer surface and, hence, the heat flux on either side of the heat transfer device.

Refrigeration: Secondary Coolants in Refrigeration Systems

Secondary coolants are liquids used as heat transfer fluids that change temperature as they gain or lose heat energy without changing into another phase. For lower refrigeration temperatures, this requires a coolant with a freezing point below that of water. These are generally called brines by the industry. This chapter discusses design considerations for components, system performance requirements, and applications for secondary coolants. Related information can be found in Chapters 3, 4, 22, 30, and 31 of the 2013 ASHRAE Handbook—Fundamentals.

Refrigeration: Concrete Dams and Subsurface Soils

Refrigeration is one of the more important tools of the heavy construction industry, particularly in the temperature control of large concrete dams. It is also used to stabilize both water-bearing and permanently frozen soil. This chapter briefly describes some of the cooling practices that have been used for these purposes.

Refrigeration: Refrigeration in the Chemical Industry

This chapter gives guidance to refrigeration engineers working with chemical plant designers so they can design an optimum refrigeration system. Refrigeration engineers must be familiar with the chemical process for which the refrigeration facilities are being designed. Understanding the overall process is also desirable. Computer programs are also available that can calculate cooling loads based on the gas chromatographic analysis of a process fluid. These programs accurately define not only the thermodynamic performance of the fluid to be chilled, but also the required heat transfer characteristics of the chiller.

Refrigeration: Cryogenics 

Cryogenic engineering is involved with the design and development of low-temperature systems and components. In such activities the designer must be familiar with the properties of fluids used to achieve these low temperatures as well as the physical properties of components used to produce, maintain, and apply such temperatures.

Refrigeration: Ultralow-Temperature Refrigeration

Ultralow-temperature refrigeration is defined here as refrigeration in the temperature range of –58 to –148°F (–50 to –100°C).What is considered low temperature for an application depends on the temperature range for that specific application. Low temperatures for air conditioning are around 32°F (0°C); for industrial refrigeration,–31 to –58°F (–35to –50°C); and for cryogenics, approaching 0°R (0 K). Applications such as freeze-drying, as well as the pharmaceutical, chemical, and petroleum industries, use refrigeration in the low-temperature range as designated in this chapter. The refrigeration cycles presented in this chapter may be used in both standard packaged and custom-designed systems. Cascade systems are emphasized, both autocascade (typical of packaged units) and two-refrigerant cascade (found in custom-engineered low-temperature systems).

Refrigeration: Biomedical Applications of Cryogenic Refrigeration

This chapter briefly describes many of the principles driving the present growth and development of low-temperature biological applications. An understanding of these principles is required to optimize design of practical apparatus for low-temperature biological processes. Although this field is growing in both breadth and sophistication, this chapter is restricted to processes that involve temperatures below which ice formation is normally encountered (i.e., 32°F [0°C]), and to an overview of the state of the art.

Refrigeration: Terminology of Refrigeration

This chapter seeks to define some of the common terms used in industrial refrigeration systems, specifically those using ammonia as the refrigerant. The glossary was compiled from a variety of sources throughout the industry, including ASHRAE, the International Institute of Ammonia Refrigeration (IIAR), the U.S. Occupational Safety and Health Administration (OSHA), and the U.S. Environmental Protection Agency (EPA). Specific sources for entries are listed in the endnotes. Minor edits for punctuation, conciseness, and consistency with usage elsewhere in the Handbook have been made.

The ASHRAE HVAC REFRIGERATION HANDBOOK may be purchased from the on-line bookstore by clicking on the highlighted text.

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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.


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.


Co-sponsored by: TC 10.5, Refrigerated Distribution & Storage Facilities, TC 10.1, Custom Engineered Refrigeration Systems

The Guide will serve designers, contractors and operators of refrigerated facilities and industrial and commercial refrigeration systems. The intent is that this Guide will be of broad interest in this sector in addition to designers, contractors, and operators, it will also be of value to educators, utilities, policy makers and others involved in the energy efficiency and sustainability ―business.


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.

ANSI/ASHRAE Standard 15: Safety Standard for Refrigeration Systems


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

What value of RCL do I use if the refrigerant I am considering in a given application does not appear in Table 4-1 or 4-2 of ASHRAE 34? (25)

How much clearance must I have between the discharge of a refrigerant relief vent line and any opening to the occupied space? (26)

What is the permissible quantity of refrigerant per occupied building volume for refrigerants? (87)

Are self contained breathing apparatuses (SCBA's) required outside of refrigeration machinery rooms? (90)

Other Activities

TIP: If MTG involvement add here otherwise leave blank.

TC 10.1 participates in the following multidisciplinary task group:
Lower Global Warming Potential Alternative Refrigerants
 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.