This research presents the development of R463A refrigerant, a nonflammable refrigerant that was retrofitted to replace R404A. R463A is primarily composed of hydrofluorocarbons/hydrocarbons/carbon dioxide (HFCs/HCs/CO₂), and has global-warming potential (GWP) of 1494. It is a nonazeotropic mixture of R32 (36%), R125 (30%), R134a (14%), R1234yf (14%), and R744 (6%). R463A is composed of polyol ester oil (POE), and it is classified as a Class A1 incombustible and nontoxic refrigerant. R463A has a higher cooling capacity (Qe) than that of R404A, as it is composed of hydrofluorocarbons (HFCs) R32 and carbon dioxide (CO₂) R744, and has lower GWP than that of R404A due to the use of hydrofluoroolefins (HFOs) from R1234yf. The results of this research showed that R463A can be retrofitted to replace R404A due to its composition of POE, Class A1 incombustibility, and lower toxicity. The properties of R463A and R404A, as analyzed using national institute of standards and technology (NIST) reference fluid thermodynamic and transport properties database (REFPROP) software and NIST vapor compression cycle model accounting for refrigerant thermodynamic and transport properties (CYCLE_D-HX) software, are in accordance with the CAN/ANSI/AHRI540 standards of the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). The normal boiling point of R463A was found to be higher than that of R404A by 23%, with a higher cooling capacity and a 63% lower GWP value than that of R404A. The critical pressure and temperature of R463A were found to be higher than those of R404A; it can be used in a high-ambient-temperature environment, has higher refrigerant and heat-rejection effects, and has lower GWP than that of R404A by 52% due to the HFOs from the R1234yf component. The cooling coefficient of performance (COPc) of R463A was found to be higher than that of R404A by 10% under low-temperature applications. R463A is another refrigerant option that is composed of 7% carbon dioxide (CO₂), and is consistent with the evolution of fourth-generation refrigerants that contain a mixture of HFCs, HFOs, HCs, and natural refrigerants, which are required to produce a low-GWP, zero-ozone-depletion-potential (ODP), high-capacity, low-operating-pressure, and nontoxic refrigerant.

This research presents an energy efficiency improvement solution for supermarkets with the use of low-E glass doors for open refrigerators and a digital semi-hermetic compressor to fix the speed of semi-hermetic compressors. The impact of a door’s installation causes its load to be reduced by 40%, and the compressor shuts down frequently, which decreases its lifetime. In order to ensure that energy-saving solutions do not affect maintenance costs, the installation of a digital semi-hermetic compressor is proposed to lower costs and save energy. Our economic results from tests carried out at a 3000 square meter supermarket, which was open from 6:00 a.m. to 12:00 a.m. and in which we installed 82 doors on 15 open refrigerators, showed a 1.1-year payback period with an energy saving rate of 192,220 kWh/year for store No.1 (R22) and in which we installed 80 doors on 15 open refrigerators, showed a 1.4-year payback period with an energy saving rate of 171,185 kWh/year for store No.2 (R404A). The energy-saving effects of the digital semi-hermetic compressor, which fixes the speed of the semi-compressor and solves the problem of impact from fridge door installation, showed a 2.9-year payback period with an energy saving rate of 26,890 kWh/year for store No.1 (R22) and showed a 2.9-year payback period with an energy saving rate of 26,571 kWh/year for store No.2 (R404A). The results of store No.1 (R22) and store No.2 (R404A) showed no differences. This research is an extension of an energy-saving project that can be carried out on a continuous basis, increasing the efficiency of energy use and being a sustainable source of energy conservation.

This research presents the improving energy efficiency by retrofitting doors for open refrigerated in central Thailand supermarkets that open in the daytime (06.00 am - 6:00 pm) and close in night-time (00.00 am – 6:00 am). The Materials and Methods were open refrigerated 15 cabinet and retrofitting doors for open refrigerated that 41 frames, 82 doors in medium temperature refrigeration system and measure power consumption kW, kWh by power meter data logger for analysis and summarize. The power consumption saving average per 7 days for retrofitting doors was 576 kWh/day, 39.67% that daytime 418 kWh/day, 41.93%, and night-time 116 kWh/day, 33.24%. Besides, the energy of day time more than night time because 1) The time of opening store is longer than closing store 2) In the night time, the refrigerated will close by plastic curtain 3) The request cooling load of day time is longer than day time 4) The sale area/ambient temperature of night time more than day time but the humidity was contrasted. Before retrofitting doors, the maximum and minimum of power consumption was 83.25 kw/hour and 44.73 kw/hour, respectively. Also, the power consumption swing at 38.52 kw/hour, 46.72%, and the maximum and minimum of power consumption after retrofitting doors was 33.15 kw/hour and 30.19 kw/hour, respectively. The power consumption swing at 2.96 kw/hour, 8.93%. In addition, the power consumption swing will after be retrofitting doors will less than before retrofitting doors by 1) The average cooling load will be the same as bolt conditions 2) The request cooling load of doors refrigerated will less than by product load, the swing of sale area temperature and humidity, customer behavior that effect power condition will have the low running operation. This research's investment was 21,694 €, while the payback period of this research was 14 months. Besides, within 1.1 years, that energy saving was 16,020 kWh/Month or 1,542 €/Month, 16,020 kWh/month or 192,220 kWh/Year or 18,503 €/Year.

This research will be presenting energy efficiency improvement options by retrofitting doors for open refrigeration systems in Central Thailand supermarkets that open during the daytime (06:00 am – 06:00 pm), and are closed during the night-time (00:00 am – 6:00 am). The materials and methods used consisted of 15 open refrigeration cabinets with 82 retrofitted doors supported by 41 frames, with the temperature set at medium. The power consumption was indicated in kW, kWh through a power meter data logger for analysis and summarization. The investment required was €21,694 /store, while the payback period of this research was determined to be at 14 months. The cost of energy savings was found to be within a period of 1.1 years, at the rate of 192,220 kWh/year or €18,503 annually. The retrofitted doors is expected to reduce the cooling load and over-burdening of the compressor. The research found that the most viable solution was to use a digital semi-hermetic compressor that can operate in unload and full load status, that was being controlled by the evaporator temperature (TEV) which was set at -10 degree, the condenser temperature (TCD) set at 38 degrees, and the superheat temperature (TSH) at 10 degrees. In the unload status, the power consumption of the digital semi hermetic compressor will decrease by 50%, which has a significant impact for energy savings and is important for night-time when low cooling load is required whereby the compressor’s multiple start–stop cycles are not required. The investment for a digital semi-hermetic compressor was determined to be €7,800/store, and is able to yield energy savings of up to 26,890 kWh/year, or €2,589 annually, with a payback period of 2.9 years.

This research presents a solution for improving energy efficiency in convenience stores by implementing a building energy management system (BEMS) that uses new logic control in air conditioning and refrigeration systems. These systems currently consume the most energy in convenience stores. Implementing this system not only reduces the energy consumption of the compressors in both systems but also minimizes energy loss due to low desired temperatures in the sale area while maintaining the cabinet temperature at the same level. An experiment was conducted at a 314-square-meter convenience store that was open from 6:00 a.m. to 11:00 p.m., and we demonstrated a 4.4-year payback period by controlling AC units close to the desired sale-area temperature of 25 degrees Celsius and increasing the suction pressure at a medium-temperature CDU by 0.3 bar or 31 kPa. This resulted in energy savings of 7.1 kilowatt-hours per day, or 2591.5 kilowatt-hours per year, for the air conditioning system and 2.8 kilowatt-hours per day, or 1022.0 kilowatt-hours per year, for the refrigeration system, resulting in a total energy savings of 9.9 kilowatt-hours per day, or 3613.5 kilowatt-hours per year. The convenience store can use the results of this research to improve the energy efficiency of its cooling system, which includes air conditioning and refrigeration systems, thereby promoting sustainable energy conservation.