Evaluation of corrosion problems in a closed air-conditioning system: a case study

A rechargeable personal air-conditioning (RPAC) device was developed to provide an improved thermal comfort level for individuals in inadequately cooled environments. This device is a battery powered air-conditioning system with the phase change material (PCM) for heat storage. The condenser heat is stored in the PCM during the cooling operation and is discharged while the battery is charged by using the vapor compression cycle as a thermosiphon loop. The conditioned air is discharged towards a single person through adjustable nozzle. The main focus of the current research was on the development of the cooling system. A 100 W cooling capacity prototype was designed, built, and tested. The cooling capacity of the vapor compression cycle measured was 165.6 W. The PCM was recharged in nearly 8 hours under thermosiphon mode. When this device is used in the controlled built environment, the thermostat setting can be increased so that building air conditioning energy can be saved by about 5–10%.

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ENERGY ANALYSIS FOR LIGHTING AND AIR-CONDITIONING SYSTEM OF AN ACADEMIC BUILDING

Jurnal Teknologi ◽

10.11113/jt.v76.5536 ◽

2015 ◽

Vol 76 (5) ◽

Author(s):

Tee Boon Tuan ◽

Ahmad Zubair Yahaya ◽

Younus Fahad Breesam ◽

Reduan Mat Dan ◽

Muhammad Zulfattah Zakaria

Keyword(s):

Air Conditioning ◽

Energy Analysis ◽

Building Energy ◽

Consumption Pattern ◽

Lighting System ◽

Energy Audit ◽

Energy Usage ◽

Air Conditioning System ◽

Academic Building

Energy analysis is important to analyze energy consumption pattern, monitoring on how the energy used varies with time in the building and how the system element interrelate. In this case study, a preliminary energy audit is done on lighting and air-conditioning system. The lighting and airconditioning system consume the highest amount from the total building energy usage. The study was conducted in the Faculty of Mechanical Engineering Building, Universiti Teknikal Malaysia (UTeM) Technology Campus. From the result shows that the air-conditioning system has contributed approximately 48.8% from the total monthly energy usage. The estimation of Building Energy Index (BEI) for the cooling load is 655.19 kWh/m²/year. Meanwhile, the BEI for lighting system is found approximately 150 kWh/m2/year.

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Experimental and Theoretical Study on the Cooling Performance of a CO2 Mobile Air Conditioning System

Energies ◽

10.3390/en11081927 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1927 ◽

Cited By ~ 4

Author(s):

Dandong Wang ◽

Binbin Yu ◽

Junye Shi ◽

Jiangping Chen

Keyword(s):

Air Conditioning ◽

Theoretical Study ◽

Cooling Capacity ◽

Air Conditioning System ◽

Cooling Performance ◽

System A ◽

Hfc 134A ◽

Expansion Valve ◽

The Impact ◽

Compressor Efficiency

CO2 (GWP = 1) is considered as a promising natural alternative refrigerant to HFC-134a in mobile air conditioning (MAC) applications. The objective of this study is to investigate the cooling performance characteristics of a CO2 MAC system. A prototype CO2 MAC system, consisting of a CO2 electrical compressor, CO2 parallel flow microchannel heat exchangers, and an electrical expansion valve, was developed and tested. Factor analysis experiments were conducted to reveal the effect of outdoor temperature on the cooling performance of this CO2 MAC system. Compared with a conventional R134a MAC system, the prototype CO2 MAC system achieved comparable cooling capacity, but had COP reductions of 26% and 10% at 27 °C and 45 °C outdoor conditions, respectively. In addition, based on refrigerant properties, theoretical cycle analysis was done to reveal the impact of evaporator, gas cooler and compressor, on the system cooling performance. It is concluded that the increase of overall compressor efficiency or the decrease of gas cooler approaching temperature could greatly improve the COP of this CO2 MAC system.

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