Refrigerant Contaminant Control
ASHRAE Technical Committee 3.3

Scope of TC 3.3

TC 3.3 is concerned with sources, generation, and control of water and other contaminants in refrigerating systems. It is also concerned with recovering, recycling, and reclaiming refrigerants with in-system cleanup methods. Identifying and quantifying contaminants are of particular interest. Properties and performances of filters and driers are within the scope of responsibility.


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 3.3 is responsible for this ASHRAE Handbook chapter.

Refrigeration: Control of Moisture and Other Contaminants in Refrigeration Systems
Moisture (water) is an important and universal contaminant in refrigeration systems. The amount of moisture in a refrigerant system must be kept below an allowable maximum for satisfactory operation, efficiency, and longevity. Moisture must be removed from components during manufacture, assembly, and ser-vice to minimize the amount of moisture in the completed system. Any moisture that enters during installation or servicing should be removed promptly. Refrigerant filter-driers are the principal devices used to remove other contaminants from refrigeration systems. The filter-drier is not a substitute for good workmanship or design, but a maintenance tool necessary for continued and proper system performance. Contaminants removed by filter-driers include moisture, acids, hydrocarbons with a high molecular weight, oil decomposition products, and insoluble material, such as metallic particles and copper oxide.

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.

Some recent programs sponsored by this TC.


Program at the Atlanta Meeting (January 2019)
SEMINAR (INTERMEDIATE): Chemistry of New and Retrofit Systems with Low GWP Refrigerants
Track: Refrigeration
Chair:  Edward Hessell, Ph.D., Member, Lanxess Solutions US, Inc., Naugatuck, CT
New low global warming potential refrigerants such as hydrofluoro-olefins (HFOs) are inherently less chemically stable than their predecessors such as hydrofluorocarbons and hydrochlorofluorocarbons.  It is imperative that their stability in the presence of lubricants, materials of construction and trace contaminants, such as processing chemicals, water and air, be understood to ensure safe and reliable long term operation of HVACR equipment.  This seminar will provide an overview of the various tests and studies being conducted to understand the system chemistry of HVACR systems using HFO refrigerants as viewed from the perspective of HVACR system manufacturers, lubricants suppliers, and refrigerant suppliers.
1. System Chemistry Comparison of HFC and Low GWP Alternatives
Julie Majurin, Member, CPI Fluid Engineering, Midland, MI
2. Evaluation of the Chemical Stability of HFC and HFO Alternatives When Applied as R22 Retrofit in Refrigeration Equipment
Hitomi Arimoto, Associate Member, Daikin Industries, Ltd., Settsu, Japan
3. Chemical Stability of New Low GWP Olefin Based Refrigerants
Stephen Kujak, Member, Trane, Ingersoll Rand, La Crosse, WI
4. What do We Need to Understand About System Chemistry and Low GWP Refrigerants
Joe Karnaz, DSc, Member, Shrieve Chemical, Houston, TX

Program at the St. Louis Meeting (June 2016)
SEMINAR (ADVANCED): Lubrication Effects Beyond the Compressor
Track: Advances in Refrigeration Systems and Alternative Refrigerants
Chair: Joseph Karnaz, Member, CPI Fluid Engineering/Lubrizol, Midland, MI
Lubricants are an essential component to effective operation of air conditioning and refrigeration compressors which are exhaustively studied by compressor engineers and tribology experts.  But there are other aspects to lubrication effects beyond the compressor which can also be key to effective operation and performance of air conditioning and refrigeration systems.  This seminar presents examples of how the lubricant circulated from the compressor into the system can affect system components, oil management and overall system performance with existing and alternate refrigerants.
1. Managing Lubricants in a Large Commercial Refrigeration System
Danny Halel, Member, Hussman Corporation, Bridgeton, MO
2.  Lubricant Management Heuristics and Impacts on System Chemistry, Valves and Other System Components
Christopher Reeves, Associate Member, Sporlan Valve Division of Parker Hannifin, Washington, MO
3.  Lubricants in Heat Exchangers: A Slippery Slope
Scott Wujek, Ph.D., Member, Creative Thermal Solutions, Urbana, IL
4. Oil Separator Efficiency Rating Dilemma
Kok-Hiong Kee, Emerson Climate Technologies, Inc., St. Louis, MO

Program at the Seattle Meeting (June-July 2014)
WORKSHOP 2 (INTERMEDIATE): Effects of Contaminants on Refrigeration System Performance
Track: Refrigeration
Chair: Warren Clough, Member, Carrier Corp., Syracuse, NY
Contaminants in a HVAC&R system can be detrimental and, at some point, impact the performance and reliability or eventually lead to a catastrophic failure. There are standards in place to minimize the level of contaminants that enter into a system. For example, Air Conditioning, Heating and Refrigeration Institute (AHRI) 700, Specification for Fluorocarbon Refrigerants, is an industry standard that controls the level of refrigerant impurities. Should a system become contaminated there are products designed to remove and control the levels allowed. Some contaminants introduced cannot be system controlled and have resulted in fatalities. Therefore, steps have to be taken to avoid such contaminants from being introduced.
1. Various System Contaminants, their Sources, and Tools to Eliminate Them
Christopher Reeves, Associate Member, Parker Hannifin Corporation, Washington, MO
2. Updates to AHRI 700 Specification for Refrigerants and the Level of Acceptable Impurities
Robert W. Yost, Member, National Refrigerants, Rosenhayen, NJ

Program at the Dallas Meeting (January 2013)
FORUM (INTERMEDIATE): What Contaminates are Important in Low GWP Refrigerant Systems?
Track: Refrigeration
Sponsor: 03.03 Refrigerant Contaminant Control, AHRI 700, 03.02 Refrigerant System Chemistry
Chair: Robert W. Yost, Member, National Refrigerants, Rosenhayen, NJ
HVAC&R systems using low GWP refrigerants are likely to be sensitive to contaminates in ways different than traditional systems. This forum discusses the contaminates most likely to affect system reliability with low GWP refrigerants, and what acceptable levels of contaminates may be needed. Methods to control these contaminates will also be discussed.


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.

TC 3.3 will identify, prioritize, and undertake research that addresses topics associated with sources, generation, and control of water and other contaminants in refrigerating systems. Related issues include recovering, recycling, and reclaiming of refrigerants; in-system clean-up methods; identifying and quantifying contaminants; and properties and performances of filters and dryers.
Research Plan  Research Plan TC3-3 2016-17
Priority 1:
WS-1740 - Hydrogen Fluoride Capacity of Desiccants

TC 3.3 has the following active projects:


Understanding the reliability and performance implications of higher levels of unsaturated fluorocarbons would be beneficial to any manufacturer by; -increasing the sustainability of refrigerant by allowing less restrictive use of HCFC and HFC’s in the market place by potentially allowing higher levels of unsaturants.

1665-RP: R-40 STABILITY WITH HVAC&R SYSTEM MATERIALS (cosponsor with TC 3.2)

The objective is to develop the understanding of the impacts of R-40 contamination on the safety and reliability of HVAC&R equipment. Outcomes of this research will be immediate adoption of safe contaminant limits by refrigerant purity specifications for SAE, AHRI standards and by HVAC&R manufacturers and users.


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.

This TC is responsible for the following standards:

ANSI/ASHRAE Standard 35: Method of Testing Desiccants for Refrigerant Drying

ASHRAE Standard 63.1: Method of Testing Liquid-Line Refrigerant Driers

ANSI/ASHRAE Standard 63.2: Method of Testing Liquid-Line Filter Drier Filtration Capability

ANSI/ASHRAE Standard 78: Method of Testing Flow Capacity of Suction Line Filters and Filter-Driers

Proposed Standard 219P: Method of Testing the Ability of Liquid Line Filter Driers or Adsorbents to Remove Organic and Inorganic Acid

This TC is working on the following proposed standards

Proposed Standard 63.3 Organic Acid Capacity MOT - Title Purpose Scope
Proposed Std MOT - Expansion Devices -- Title Purpose Scope - Jan 2014

Other Activities

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


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