Low GWP Refrigerants for Air Conditioning and Chiller Applications

Refrigerants with low environmental impact have been developed as replacements for R410A in stationary air conditioning applications. Non-flammable and mildly flammable low global warming potential (GWP) refrigerants, have been evaluated in representative R410A residential equipment. This study discusses the performance these replacements for ambient temperatures ranging from 28oC to 46oC. Replacements for R410A and R134a are also discussed for high pressure and medium pressure chiller applications respectively. Results obtained from system simulation are discussed in detail showing the benefits of using these new fluids

Refrigerants With Low Environmental Impact For Commercial Refrigeration Systems

New refrigerants with the positive attributes of both high thermal performance and low environmental impact are currently in development. These refrigerants provide high energy efficiency, which coupled with low GWP significantly reduce the total environmental impact compared with current fluids (R404A, R507, R22 and R134a). Properties, and experimental results are compared and discussed for refrigeration applications. Alternative system architectures for refrigeration applications utilizing the beneficial characteristics of these new fluids are also discussed. A holistic analysis approach is used to evaluate the lifetime environmental and operational impact for the refrigerants and systems presented in this study

Low GWP Refrigerants for Air Conditioning Applications

Refrigerants with low environmental impact have been developed as replacements for R22 and R410A in air conditioning applications. L-20 and L-41 have been evaluated in representative residential equipment. This study discusses the performance at high ambient temperatures (warm climate) and potential design changes. In addition, 1233zd and 1234ze have been evaluated as replacements for R123 and R134a in low and medium pressure chiller applications. Theoretical and experimental results are discussed in detail showing the benefits of using these new fluids

Refrigerants with Low Environmental Impact for Refrigeration Applications

New refrigerants with considerable low environmental impact are currently under evaluation by the refrigeration industry. Such refrigerants could be used in place of high global warming fluids like R404A. Among these new fluids are 1234ze, N-13, L-40 and N-40. Initial laboratory evaluations of these refrigerants showed good energy efficiency due to their good thermal properties. These initial evaluations were followed by larger scale (field) trials, refrigerant–oil property measurements, and also material compatibility. This study presents and discusses results of such evaluations, and extends the assessment to LCCP using different refrigeration technologies and refrigerants

Reduced GWP Refrigerant for Residential and Commercial Air Conditioning Systems

R-410A is widely used in residential and light commercial air-conditioning, heat pump and chiller systems. Due to increasing concerns about climate change, various environmental regulations have been proposed to phase out this refrigerant. A new refrigerant, R-466A, has been developed, which offers high energy efficiency and low global warming potential (GWP), resulting in low overall environmental impact. This paper discusses the thermal properties as well as the performance of this new refrigerant in a representative air conditioning system showing the benefits of using this new refrigerant. The thermal stability, material compatibility and refrigerant/lubricant interactions of R-466A are also discussed. Finally, a simulation model is used to evaluate the lifetime thermal stability of R-466A under real operating conditions for a heat pump system

Use of Blends in Commercial Refrigeration Systems: Fractionation characteristics and material compatibility of R448A

The development of lower global warming potential (GWP) blends offers an alternative for the widely used high GWP fluids such as R404A. Commercial refrigeration systems for supermarkets are a common example for such systems. These kinds of systems show relatively large refrigerant leakage rates of 15% to 20% per year. The newly developed R404A lower GWP alternatives are zeotropic blends, meaning they show a temperature glide during phase change processes in the evaporator and condenser of the system. Because of the glide, there is a concern within end users that the blend components could separate, or fractionate, during a leak event. Â This paper will describe the results from tests carried out to determine the effect of refrigerant fractionation and its effect on the performance of an actual refrigeration system subject to multiple leak events. The second part of this paper provides characteristics for the solubility and miscibility of R448A with POE oil and results from a material compatibility study of R448A with common materials used in refrigeration equipment

Latest Developments of Low Global Warming Refrigerants for Chillers

This paper will focus on the developments of new molecules that have low global warming potential, high thermal performance, and favorable safety characteristics, to name only a few required characteristics. Several new molecules that have very short atmospheric lifetimes, as well as refrigerant blends utilizing these molecules, have been developed and will be evaluated for use in various types of water chillers ranging from smaller capacity systems that currently use R-410A or R-407C refrigerants to larger centrifugal compressor chillers that have currently used R-134a or R-123. Thermodynamic and system simulations were carried out using low GWP refrigerant properties and compared against the baseline refrigerants. These new LGWP refrigerants show promise in these applications and warrants further development

Low Global Warming Refrigerants For Commercial Refrigeration Systems

New refrigerants with the positive attributes of both high thermal performance and low environmental impact are currently in development. Initial evaluation of these refrigerants in refrigeration systems show good energy efficiency and significant lower global warming impact than current refrigerants. Some of those Low GWP refrigerants are non-azeotropic blends with moderate to high glide; therefore guidance on the use of these blends is needed to achieve the desired good performance and low environmental impact. This study discusses glide effects on the performance and operation of refrigeration systems. Issues related to servicing systems such as fractionation are also discussed. Data is presented using current refrigerants such as R407F and other refrigerant blends currently under development