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Concerns about the impact on the environment of the refrigerants used in HVAC&R equipment are driving the development of alternative refrigerants with lower global warming potentials (GWPs). This paper reports the performance of DR-55 (now designated as R452B), DR-5A (now designated as R454B), and R32 in comparison to R410A at the component level from tests run on a 4 RT (14 kW) commercial unitary rooftop heat pump. Overall unit performance was previously reported (Schultz and Kujak, 2016), showing DR-55 and DR-5A to be design-compatible replacement candidates for R410A. This paper further confirms this by comparing performance at the compressor, evaporator, and condenser component level.

Hydrofluorocarbons (HFCs) have replaced chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) as non-ozone depleting fluids in many applications, including as refrigerants, solvents, aerosols, and blowing agents for insulating foams. However, some HFCs have relatively high Global Warming Potential (GWP) and are coming under closer scrutiny due to the increasing concern over global climate change. The focus now is on the search for the next generation of environmentally sustainable working fluids with negligible direct environmental impact in terms of both ozone depletion and global warming potential. Development of low-GWP options should be balanced with respect to safety, performance, ease of use, and energy efficiency. Indeed, greenhouse gas emissions come not only from direct emissions but also largely from indirect sources based on energy consumption. It is therefore important that energy efficiency remain a primary consideration when implementing low-GWP solutions, as replacing a high-GWP fluid with a lower GWP, but less efficient option may actually increase greenhouse gas emissions, thereby degrading the overall Life Cycle Climate Performance (LCCP). This paper introduces a novel low GWP refrigerant composition to replace R-134a. Thermodynamic properties as well as theoretical and experimental evaluation of this refrigerant is being discussed. Results are compared to baseline

Today air conditioning product and applications designers, as a result of climate change contribution concerns for high direct global warming potential (GWP) refrigerants, are being asked to consider lower GWP refrigerants with various degrees of flammability. In recent year, the HVACR industry has been actively investigating the safety of flammable refrigerants by determining their risks, potential occurrences and severity of events. Today R410A is used to cover most air conditioning applications and all lower GWP alternatives presented to date have some degree of flammability with most being ASHRAE 34 flammability class 2L.  A novel R410A alternative refrigerant blend, R452B or DR55, has recently been studied in a 4 ton RTU to determine the potential for compositional fractionation in various modes of operation. In addition, the ASHRAE flammability process needed to classify refrigerant flammability and flammability classification data for R452B will be presented in this paper. The unit compositional data and the ASHRAE classification process and data will be compared and contrasted to show differences in potential flammability interpretations and design safety implications.

This project educates biblical counselors to be more effective counselors by overcoming difficulties in counseling those who have various reading issues. Chapter 1 introduces the project by describing the purpose, goals, rationale, definitions, limitations, delimitations, and research methodology for the project. This chapter examines the ministry context, history, and community demographic for the Randolph Area Biblical Counseling Center. Chapter 2 provides the biblical and theological rationale for counseling those whose reading problems hinder the process. Chapter 3 presents the theoretical and practical issues related to counseling those whose reading problems hinder the process. Chapter 4 explains how the project was implemented, including training provided to leaders, research instruments for measuring success, and a description of the activities undertaken during the fifteen-week project period. Chapter 5 contains an overall evaluation and analysis of the project along with theological and personal reflections.

Societal demands to control climate change are driving the development of many Life Cycle Climate Performance (LCCP) tools to understand how to minimize the total environmental impacts of HVAC&R products and technology. The LCCP models can be extremely detailed, accounting for all CO2 contributions from “cradle” (refrigerant and product manufacturing), through use (including servicing and potential leak rates by type of product), to “grave” (recycling and disposal) for a product. LCCP tools have been developed for a number of HVAC&R product segments and continue to grow in number. However, there are few studies into understanding how the results from these various tools compare to each other against the latest available lower Global Warming Potential (GWP) next generation refrigerant technology. Because global regulatory discussions currently are focusing on reducing direct GWP contributions of refrigerants and for the most part are ignoring their impact on indirect GWP contributions as refrigerant choices are considered, there is potential for regulators to reduce the available refrigerant choices that would allow manufacturers to minimize the total environmental impact (lowest LCCP) through maximum efficiency. This paper will provide an overall assessment of using the latest available refrigerants technology with four LCCP tools. LCCP tools for the stationary refrigeration, transport refrigeration, chiller, and unitary product segments will be compared to understand the impact of reducing the direct GWP of a refrigerant given the latest refrigerant technology. This paper will suggest appropriate GWP limits for refrigerants by application, since direct GWP limits may need to be defined by application type based on the available refrigerant technology to minimize environmental impacts.

Growing concerns about the impact on the environment of the refrigerants used in HVAC&R equipment are driving development and evaluation of alternative refrigerants with lower global warming potentials (GWPs). The Air Conditioning, Heating, and Refrigeration Institute (AHRI) recently coordinated the Low-GWP Alternative Evaluation Program (AREP) in which commercial, university, and government laboratories ran tests of a range of alternative refrigerants in a variety of HVAC&R products. This paper will report the performance of an ~4.4 RT air-cooled water chiller/heat pump run with a number of lower GWP alternative refrigerants. Tests were first run with a compressor designed for R410A-like pressures. The refrigerants tested include R410A (baseline) and R32, along with blends labeled DR-5, DR-4, L-41a, L-41b, ARM-70a, ARM-32a, and HPR1D. The compressor was then replaced with one designed for R22-like pressures. The refrigerants tested include R22 (baseline) along with blends labeled DR-4, DR-7, ARM-32a, L-20, LTR4X, and LTR6A. The blends contain R32, R1234yf, R1234ze(E), R134a, R152a, R125, and R744 (CO2) in various compositions. The results of this project have been reported previously for performance measured at the nominal operating condition of 7.2°C (45°F) leaving chiller water temperature and 35°C (95°F) air temperature (Schultz and Kujak, 2012, 2013a, 2013b; Schultz, 2014). In this paper, performance over an extended range of air temperatures from 25°C to 45°C (77°F to 113°F) will be reported and compared to a simple thermodynamic cycle model. As already reported, the predictions of the thermodynamic cycle model and measured performance are in good agreement at the nominal operating condition. However, some deviations were observed between the measured and modeled performance for air temperatures away from the nominal condition. In particular, the predicted performance benefits of some refrigerants were not observed at elevated air temperatures. On the other hand, none of the alternative refrigerants performed significantly worse than R410A at elevated air temperatures. These discrepancies indicate there are factors that need to be accounted for other than the thermodynamic properties of the refrigerants. These factors will be discussed here. Schultz and Kujak, 2012, “TEST REPORT #1?–?System Drop-in Test of R-410A Alternative Fluids (ARM-32a, ARM-70a, DR-5, HPR1D, L-41a, L-41b, and R-32) in a 5-RT Air-Cooled Water Chiller (Cooling Mode)”, AHRI Low-GWP Alternative Refrigerants Evaluation Program website, http://www.ahrinet.org/ahri+low_gwp+alternative+refrigerants+evaluation+program.aspx Schultz and Kujak, 2013a, “TEST REPORT #6?–?System Drop-in Tests of R-22 Alternative Fluids (ARM-32a, DR-7, L-20, LTR4X, LTR6A, and D52Y) in a 5-RT Air-Cooled Water Chiller (Cooling Mode)”, AHRI Low-GWP Alternative Refrigerants Evaluation Program website, http://www.ahrinet.org/ahri+low_gwp+alternative+refrigerants+evaluation+program.aspx Schultz and Kujak, 2013b, “Comparative performance of low GWP alternate refrigerants for R410A and R22 in a small air-cooled chiller”, Proceedings of ICCR3013 – 5th International Conference on Cryogenics and Refrigeration, 06-09 Apr 2013, Hangzhou, China, Paper ID B-4-09. Schultz, 2014, “Performance of R410A and R22 Alternative Lower GWP Refrigerants in a Small (~5 RT) Water Chiller”, presented at the ASHRAE Winter Conference, 19-22 Jan 2014, New York City, Conference Paper NY-14-C066.