Tech Update

AHRI’s TechUpdate e-newsletter is published three times a 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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March 2014

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AHRI Presents Research Findings at Low-GWP AREP Conference

In addition to its regular research activities, AHRI is conducting the Low-Global Warming Potential Alternative Refrigerants Evaluation Program (Low-GWP AREP) to identify and evaluate promising alternative refrigerants for major product categories including air conditioners, heat pumps and heat pump water heaters, dehumidifiers, chillers, ice makers, and refrigeration equipment. This ongoing industry-wide cooperative research program began in 2011 and aims to help the HVACR industry select the most promising refrigerants, avoid duplicative work, understand technical challenges, and identify the research needed to use these refrigerants. The program does not prioritize these alternatives; rather, it seeks to identify potential refrigerant replacements for high-GWP refrigerants, and present the performance of these replacements in a consistent and standard manner.

On January 16, AHRI hosted the Low-GWP AREP Conference, during which 20 technical experts presented findings from Phase I of the program, which was concluded in December 2013 and encompassed the first three years of research. All test reports issued to date are available on AHRI’s website. More than 150 people attended the conference at the New York Hilton Midtown, which included presentations from 16 test entities from the industry, academia, and national laboratories. The conference presentations are online here.  

AHRI Seeks Refrigerant Research Participants for the Second Phase of Low-GWP AREP

In January, AHRI launched a second phase of the Low-Global Warming Potential Alternative Refrigerants Evaluation Program (Low-GWP AREP). AHRI will continue research in areas that were not previously addressed: refrigerants in high ambient conditions (i.e., warmer climates); refrigerants in applications not tested in the first phase; and new refrigerants identified since testing for the program began.

AHRI invites applications from original equipment manufacturers (OEMs), universities, and laboratories to perform tests on refrigerants for the second phase. Interested companies are encouraged to contact AHRI Vice President of Regulatory and Research Karim Amrane to request a copy of the Program Handbook, which provides details such as the particulars of the program and required testing conditions.

AHRI Completes Three Research Projects in 2013

In 2013, AHRI published the final reports of the following research projects. The reports are available to members on the AHRI website.

AHRI-8006: Low Global Warming Potential (GWP) Refrigerants, Phase II: Defining the Configurations of Residential Air-Conditioning and Heat Pump Systems Using Hydrocarbons, Ammonia, Carbon Dioxide, and HFO-1234yf as Refrigerants and Meeting Previously Defined Safety Requirements. The project summarized the configurations of air-conditioning/heat pump systems using low GWP refrigerants which can meet regulations, codes and standards’ safety requirements, and explored the feasible design options which allow the safe use of the above-mentioned low GWP refrigerants.

AHRTI-06030-02: Novel Materials for Heat Exchangers, Phase II. The project provided performance data necessary for a more complete design and analysis of metal and carbonaceous foams as heat exchanger materials. Metal foam heat exchangers were built and tested.

AHRTI-09005: ASHRAE SPC 177P Fractionation Apparatus Evaluation. This project evaluated the adequacy of a proposed apparatus design and test procedure for conducting fractionation measurements to verify fractionation analysis of refrigerant blends.

Ongoing Research Projects Cover Wide Range of Products

AHRI’s research projects often take several months or even years to complete. The following projects are ongoing this year.

AHRI 8002: Study of Impact of Duct Design on Life Cycle Cost of Residential HVAC Systems. This project conducts a life cycle cost analysis of typical residential air conditioning systems (i.e.: cooling equipment, furnace, and ductwork) to determine what operating conditions (e.g.: airflow rate and static pressure) result in minimum life cycle system costs (i.e.: first costs and energy costs). The intent of this proposed work is to determine how ductwork should be sized in new construction to minimize life cycle cost to the homeowner (first cost of the ductwork vs. operating cost of the fan to move the air through it). The project is ongoing at the Illinois Institute of Technology and a draft final report is under review by the Project Monitoring Subcommittee.

AHRI-8007: Material Compatibility & Lubricants Research for Low-GWP Refrigerants. The objective of this project is to determine low- global warming potential refrigerants HFO-1234yf, HFO-1234ze(E), and R-32, and lubricants’ long-term material compatibility with materials commonly used in stationary air conditioning and refrigeration systems. Motor insulations, seal materials (i.e.: elastomer and gaskets), and miscellaneous structural materials will be tested. The project is ongoing at Trane and expected to be completed in April 2014.

AHRI-8009: Risk Assessment of Refrigeration Systems Using A2L Flammable Refrigerants. The objective of this project is to use fault tree analysis to conduct risk assessment for small commercial refrigeration equipment using A2L flammable refrigerants. The scope of the risk assessment is to evaluate risks during the operation and service of HFC-32 (GWP of 675), HFO-1234yf (GWP of 4), or HFO-1234ze (GWP of 6) in a self-contained reach-in cooler and a single condensing unit connected to refrigeration unit(s). The project is ongoing at Gradient and expected to be completed in February 2015.

AHRI-8010: Universal Vent for Common Venting High-Efficiency and Draft-Hood Equipped Gas Appliances. The objective of the project is to test the performance of the universal vent found in the field under various scenarios. The universal vent is a tee, which the furnace flue gases enter through an aspirator, designed to eliminate the opportunity for (1) condensation within the common vent, (2) spillage of flue gases into the space through the water heater draft hood during furnace-only operation, and (3) safe venting during water heater-only operation. The study explores performance of the aspirator under several environmental conditions through lab testing and computational fluid dynamics (CFD) simulation. The project is ongoing at Gas Technology Institute (GTI) and expected to be completed in March 2014.

AHRI-8012: Developing Fan Power Terminal Unit Performance Data and Models Compatible with EnergyPlus. This project is to develop a broad range of fan/motor efficiency data that can be readily used in EnergyPlus. Models for alternative configurations/operations of series and parallel units will be developed. A leakage model is planned to be incorporated into the EnergyPlus model. The project is ongoing at Baylor University and expected to be completed July 2015.

AHRI-8013: A Study of Methods to Represent Compressor Performance Data Over an Operating Envelope Based on a Finite Set of Test Data. This project has two objectives:(1) to determine the optimal method to represent performance data over the application envelope which maximizes accuracy for a given number of test points and (2) to develop an estimate of the level of uncertainty in the each method as a function of measurement reproducibility and/or product-to-product variation, especially at the typical rating points given in the performance rating standard. The project is ongoing at Optimized Thermal Systems and expected to be completed July 2014.

AHRTI-09006: Joining Techniques Assessment. This project aims to develop a standard method of rating the tightness of different types of joints based on laboratory data and to provide guidelines so manufacturers can reduce leaks from their products by selecting high-performing joints. The overall goal is to determine what types of joining technologies are and are not acceptable for HVACR applications. The project is ongoing at Energy Research Innovation Engineering. A draft final report is under review by the Project Monitoring Subcommittee.

In addition to the projects listed above, AHRI plans to begin conducting the following research projects in 2014.

•    AHRI-8011: Field Evaluation for Combustion Appliance Auditing

•    AHRI-8014: The Effect of Lower Return Air Temperatures on Furnace Heat Exchangers

•    AHRI-8015: Leak Rates Assessment for Air Conditioning and Refrigeration Equipment

AHRI/ASHRAE Co-funded Projects Leverage AHRI Resources, Benefit Members

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

Published Reports in 2013:

: Energy Efficiency and Cost Assessment of Humidity Control Options for Residential and Small Commercial Buildings. The objective of this research was to assess the humidity control approaches for residential buildings by developing appropriate simulation tools. Ducted systems and variable speed mini-split systems with different humidity controls were simulated.

AHRTI-ASHRAE-1580: Study of Input Parameters for Risk Assessment of 2L Flammable Refrigerants in Residential Air Conditioning and Small Commercial Refrigeration Applications. The objective of this project was to develop critical input data for 2L refrigerants which can be used in risk assessments for residential air conditioning, heat pumps and small commercial refrigeration applications in occupied spaces.

: Develop Alternative Setup Guidelines for Unitary Air Conditioning Test Configurations Which Cannot Adhere to ASHRAE 37/ASHRAE 116, Specified Duct Dimensions and External Static Pressure Tap Locations.The objective of this project was to experientially develop standardized geometry that will be utilized by laboratories when necessary to test unitary air conditioning equipment in configurations that deviate from ASHRAE-specified duct dimensions and external pressure tap measurement locations.

Ongoing ASHRAE Projects:

AHRTI-ASHRAE-1467: Balancing the Latent Heat Load between Display Cases & Store Comfort Cooling. This project seeks to provide a comprehensive assessment of energy savings potential in supermarkets by optimized design and operation of the combined HVACR systems.

AHRTI-ASHRAE-1507: Binary Refrigerant Flame Boundary. The project aims to develop, through a literature search, a database of past pertinent binary flame boundary concentrations, and to determine, through laboratory measurements, values for 10 additional refrigerant component pairs of commonly used and newly introduced flammable/nonflammable refrigerants pairs. This project is ongoing at Safety Consulting Engineers.

AHRTI-ASHRAE-1535: A Heat Transfer and Friction Factor Correlation for Low Air-Side Reynolds Number Applications of Compact Heat Exchangers. The objective of this research is to develop airside heat transfer and pressure drop correlations for high performance compact heat exchangers under low-air velocity conditions. The project is ongoing at Florida International University.

AHRTI-ASHRAE-1584: Assessment of Alternative Approaches to Predicting the Burning Velocity of a Refrigerant. The objective of this project is to determine if there are less expensive, but reliable alternative methods to calculating refrigerant flame speeds to direct measurements. This project is ongoing at Northeastern University.

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 in the Guide will be used for the design of new facilities, expansions, and remodels, as well as provide guidance on improvements and operating methods that may also be applied to existing facilities. ASHRAE awarded the contract to Massey University.

AHRTI-ASHRAE-1641: Effect of Unsaturated Fluorocarbon Contaminants on the Reliability and Performance of HVACR Equipment. This project aims at developing chemical reactivity information on unsaturated fluorocarbon contaminants to help the HVACR industry understand its impact on the performance and reliability of products. The results from this work will advance knowledge to support the HVACR industry in revising the limits for unsaturated compounds in various refrigerants in operating equipment, as well as new and reclaimed refrigerants. This project is ongoing at Spauschus Associates.

AHRTI-ASHRAE-1665: R-40 Stability with HVACR System Materials. This project looks to determine the stability of R-40 (monochloromethane) with HVACR system materials, so that all industries who use refrigerants can determine the reliability and safety impacts that R-40 has on equipment. R-40 has recently been determined as the primary contaminant in mobile R-134a HVACR systems and, to a more limited extent, reported in R-22 and R-410A systems as well. This project is ongoing at McCampbell Analytical Inc.