Tech Update

AHRI’s TechUpdate e-newsletter is published twice each year and includes the latest information on AHRI’s research initiatives, including recently concluded research reports and ongoing projects.

The AHRI Research Program supports AHRI’s advocacy positions, standards program, and certification program. It is a pre-competitive, basic research program that provides AHRI members with the scientific knowledge and design tools needed for the development of the next generation of energy efficient, environmentally-friendly HVACR equipment.

The AHRI Research and Technology Committee administers the program. The Committee recommends and takes measures to promote research activities and provides guidance and direction to staff concerning research and technology programs of AHRI. AHRI research projects are funded and managed entirely by AHRI or one or more of its product sections. AHRI closely works with ASHRAE to leverage its program by co-funding with ASHRAE on projects that are of interest to AHRI members. Final reports are made available on AHRI’s website.

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January 2018

AHRI Flammable Refrigerants Research Initiative

AHRI is leading a collaborative flammable refrigerants research program with support from ASHRAE, the California Air Resources Board (CARB), and the U.S. Department of Energy (DOE). This $5.6 million research program is designed to fill in the knowledge gaps leading to the safe use of flammable refrigerants, and is part of an ongoing global effort to phase down the use of high-GWP refrigerants and identify appropriate climate-friendly alternatives. Of the total, DOE is contributing $3 million, ASHRAE $1.3 million, AHRI $1 million, and CARB $0.3 million.

The goal of the research initiative is to deliver scientific findings and produce publicly available technical references to support codes and standards activities related to the use of flammable refrigerants. The program includes the following key research projects (Leading organization, project number, and status are listed in parenthesis).

  • Benchmarking Risk by Whole Room Scale Leaks and Ignitions Testing for A2L Refrigerants (AHRTI-9007-01, completed)
  • Whole Room Scale Leaks and Ignitions Testing for A3 Refrigerant (AHRTI-9007-02, ongoing)
  • Investigation of Hot Surface Ignition Temperature for A2L Refrigerants (AHRTI-9008, completed)
  • Leak Detection of A2L Refrigerants in HVACR Equipment (AHRTI-9009, completed)
  • Determination of Liquid/Vapor Composition of Refrigerant Escaping from Refrigerating Equipment During ON and OFF Cycles (AHRTI 9012/Oak Ridge National Laboratory, ongoing)
  • Flammable Refrigerants Post-ignition Risk Assessment (ASHRAE-1806, ongoing)
  • Guidelines for Flammable Refrigerant Handling, and Equipment Servicing and Installation (ASHRAE-1807, draft report under review)
  • Servicing and Installing Equipment using Flammable Refrigerants: Assessment of Field-made Mechanical Joints (ASHRAE-1808, ongoing)
  • Investigate the Proper Basis for Setting Charge Limits of A2L, A2, And A3 for Various Types of Products (Oak Ridge National Laboratory, ongoing)
  • Modeling Tools for Low-GWP Refrigerant Blends Flammability (National Institute of Standards and Technology, ongoing)

AHRI conducted its second round survey of equipment manufacturers and relevant safety standard committees and working groups to identify knowledge gaps and research needs for flammable refrigerants. The AHRTI Flammable Refrigerants Subcommittee will meet at AHRI in January 2018 to review the survey responses and identify high-priority projects.

New Projects Begun
  • AHRTI-9007-02: Whole Room Scale Leaks and Ignitions Testing for A3 Refrigerant: The objective of this project is to conduct refrigerant leak and ignition testing under whole room conditions to understand the risks associated with the use of R290, an A3 refrigerant, in commercial and residential air conditioning applications and commercial refrigeration applications. This project is financially supported by the California Air Resources Board (CARB) and is a part of the flammable refrigerant research program. The testing will be conducted at UL and is expected to begin in the first quarter of 2018.

  • AHRTI-9012: Determination of Liquid/Vapor Composition of Refrigerant Escaping from Refrigerating Equipment During ON and OFF Cycles (AHRTI 9012) The objective of this project is to conduct refrigerant leak testing under real life conditions (operating and static) to document the pressure decay rate, the mass flow rate of leaked refrigerant, and the quality (vapor versus liquid) of the leaking refrigerant as a function of time. The Oak Ridge National Laboratory is carrying out the work for AHRTI.
Projects Open for Bid

The following two projects are currently open for bid. Qualified bidders are encouraged to contact AHRI for details.

  • AHRI-8019: Common Venting of Multi Unit Installations Using Other Than Category I Vent Systems: The objective of the project is to fully understand the performance and safety for the venting of multiple (other than Category I) unit installations where the units are connected into a single vent.

  • AHRI-8020: Assessment of Fan Energy Rating Standards Criteria: The objective of the project is to use empirical model analysis augmented with experimental data to understand the variation in Fan Energy Rating (FER) that occurs within, and across, model families.
Ongoing Research Projects
  • AHRI-8013-02: A Study of Methods to Represent Compressor Performance Data over an Operating Envelope-Variable Speed Compressors: The objective of this project is to quantify the uncertainty of published compressor performance across not only the operating map but also the entire operating range of the compressor.

  • AHRI-5009: Experimental Testing of Various Boiler Types per ASHRAE/AHRI Standard 155P Method of Testing for Rating Commercial Space Heating Boiler Systems (AHRI 5009): The objective of the project is to validate the draft version of ASHRAE/AHRI Standard 155P (Standard 155P).

  • AHRI-5010: Walk-in Coolers and Freezers Hot Gas Defrost Testing: The objective of the project is to conduct laboratory testing to determine electric energy input and thermal load additions associated with defrost of hot gas defrost-dedicated condensing systems under non-frosted coil conditions.
Recently Published AHRI Research Reports

AHRI published the following three project reports in the second half of 2017. The reports are available to the public on the AHRI website.

  • AHRTI-9008: Investigation of Hot Surface Ignition Temperature for A2L Refrigerants: The project was developed to assist in the evaluation of the propensity of A2L refrigerants (R32, R1234ze, and R452B) to ignite on hot surfaces. A test apparatus was designed and built to carry out tests discharging a 5g charge of refrigerant or refrigerant/oil mixture out of a tube onto a hot, flat plate. Five replicate tests were performed for each test condition. None of the pure tested refrigerants ignited at hot plate temperatures up to 850°C (1562°F), and none of the refrigerant mixtures with 3% oil by mass ignited with the hot plate temperatures up to 800°C (1472°F).

  • AHRTI-9009: Leak Detection of A2L Refrigerants in HVACR Equipment: The objective of the project was to conduct a thorough review of available sensor technologies that can be used to detect A2L refrigerants, easily integrated into HVACR equipment, and meet the requirements defined by relevant safety standards. In this project, infrared, electrochemical cell, metal oxide semiconductor, catalytic, and heated diode sensors were reviewed and analyzed to determine whether they can meet the proposed sensor requirements under standards ASHRAE 15, IEC 60335-2-40, and ISO 5149-3.

  • AHRI-8017: Investigation of Energy Produced by Potential Ignition Sources in Residential Application: The primary objective of this project was to perform tests to determine the viability of various common ignition sources inside residential homes to ignite A2L refrigerants in air. The tested refrigerants included R-32, R-452B, R-1234yf, and R-1234ze. Among 15 identified potential ignition sources, 11 were unable to ignite any of the refrigerant-air mixtures. These were: cigarette insertion, barbeque lighter, plug and receptacle, light switch, hand mixer, cordless drill, friction sparks, hair dryer, toaster, hot plate insertion, and space heater insertion. Four of 15 ignition sources resulted in ignition when refrigerants reached their flammable concentration levels in the air. These were: hot wire (above certain high temperature), safety match, lighter flame insertion, and leak impinging on candle.
AHRI/ASHRAE Co-funded Projects

AHRI works closely with ASHRAE to leverage the AHRI research program by co-funding projects of interest to AHRI member, some of which are listed below. All AHRI/ASHRAE co-funded project final reports are available to AHRI members upon request.

Ongoing Projects:

  • AHRTI-ASHRAE 1634, Guide for Sustainable Refrigerated Facilities and Refrigeration Systems: The objective of the project is to develop a guide for sustainable refrigerated facilities and refrigeration systems. Information will be used for the design of new facilities, expansions, and remodels, as well as to provide guidance on improvements and operating methods that may also be applied to existing facilities. This project is ongoing at Massey University.

  • AHRTI-ASHRAE1645, Development of New Accelerated Corrosion Tests for All-Aluminum Microchannel and Tube and Fin Heat Exchangers: The objective of this research is to develop a new corrosion test, or to justify the use of an existing standardized accelerated test, for both all-aluminum tube and fin and brazed microchannel heat exchangers. This project is ongoing at the University of Northern Texas.

  • AHRTI-ASHRAE-1717, Improve Accuracy and Reproducibility of ASTM-E681 Test Method for Flammability Limit Measurement of 2L Flammable Refrigerants: The project will identify modifications needed for testing new alternative refrigerants for flammability following ASTM E681 to allow ASHRAE SSPC 34 to properly identify their safety classification for use by the industry. The project is ongoing at the University of Maryland.

  • ASHRAE-1721-RP, Oil Return and Retention in Unitary Split System Gas Lines with HFC and HFO Refrigerants: The objective of this research is to collect sufficient data to develop normalized rules that will allow design engineers to confidently specify line sets for all current refrigeration-oil combinations as well as future combinations in cooling and heating applications. This project is ongoing at Purdue University.

  • ASHRAE 1733-WS, Develop Design Criteria for Psychrometric Air Sampler and Mixer Apparatus for Use in ASHRAE Test Standards: The objective of this project is to develop optimized design recommendations for indoor and outdoor air samplers, as well as mixers.

  • ASHRAE 1741-RP, Understanding Fan Coil Components and How They Relate to Energy Consumption and Energy Modeling: The objective of this research project is to provide the industry with part-load capacity and efficiency performance maps for fan coil units at the airflows and water flows required to meet the loads of the building.

  • ASHRAE-1743-RP, Effect of Inlet Duct and Damper Design on ASHRAE 37/116 Fan Performance and Static Pressure Measurements: The objective of this research is to develop a set of design guidelines/requirements for the construction of an inlet duct and/or damper apparatus for inclusion in a test standard.

  • ASHRAE-1769-WS, Experimental Evaluation of the Efficiency of Belt Drives for Fans: The objective of this research is to conduct necessary testing to determine the efficiency characteristics of belt drives for fans, and to develop a belt efficiency model covering full and part-load operation. This information is needed to support fan system selection decisions and future standards, codes, and regulations.

  • ASHRAE 1773-RTAR, Ignition Potential from Electrical Devices in Commercial and Residential Applications using 2L Refrigerants: The objective of this project is to review ignition testing using 2L refrigerants; carry out testing of minimum ignition energy (MIE), including MIE testing with HVAC components; and provide guidelines for intrinsically safe electrical components.

  • ASHRAE 1774-RP, Effect of System Chemicals Towards the Breakdown of Lubricants and Lower GWP Refrigerants: The objective of this project is to generate and present results from post-exposure evaluations of sealed glass tube samples prepared with lower GWP refrigerants, lubricants, and process chemicals to facilitate assessments on the relative chemical compatibility risks of lower GWP refrigerants.

  • ASHRAE 1785-RP, Refrigerant Charge Modeling in Coils for Residential Split Systems: The objective of this project is to develop a test methodology for measuring both oil retention and refrigerant charge of round tube plate fin heat exchangers and to obtain these data using the developed test method. The data could be used by the industry to verify, select, and correlate models as required. The project is ongoing at Oklahoma State University.

  • ASHRAE 1791-WS, Humidity Effects on Burning Velocity: The objective of this project is to identify the need for testing refrigerant burning velocity in humid air for purposes of classification.

  • ASHRAE 1798-RTAR, Impact of Combustion Emissions from Gas-Fired Unvented Combustion Devices on Indoor Air Quality: The objective of this project is to investigate the impact of gas-fired unvented space heater (ANSI Z21.11.2) combustion emissions on indoor air quality in a residential building that complies with ASHRAE Standard 62.2.

  • ASHRAE 1802-RTAR, Defining the 2 / 2L Flammability Boundary in Standard 34: The objective of this project is to identify a technically sound approach to defining the 2L sub-classification.