In this study, the experimental performance of use R1234yf refrigerant al-ternative to R134a in an automobile air conditioning system with var-iable capacity compressor was investigated. The conditioner con-sists a variable compressor, evaporator, condenser, liquid tank and expansion element. is equipped computer-aided control systems obtain desired conditions data col-lection for measuring col...

In small to medium scale buildings located in the subtropics, such as Hong Kong, direct expansion air conditioning (DX A/C) systems are widely applied. This is because, as compared to chilled water based central air conditioning systems, DX A/C systems are compact, flexible for multi-room services, energy efficient and cost less to maintain and operate. However, traditionally, a DX A/C system i...

Air conditioning systems of houses consume large quantity of electricity. To reducing energy consumption for air conditioning purposes it is becoming attractive the use of evaporative cooling air conditioning which is less energy consuming compared to air chillers. But, it is obvious that higher energy efficiency of evaporative cooling is not enough to judge whether evaporative cooling economic...

Automotive air conditioning (AAC) system with a variable displacement compressor (VDC) sometimes tends to experience hunting problems, where the system undergoes oscillation. The purpose of this paper is to study the hunting phenomena in this system and to find out the factors to cause the system stability by experimental investigation. In this paper, the test bench and testing method are descr...

Blade cooling is a relevant topic in the design of modern gas turbine engines, because of the increase in performance due to the resulting increase in the inlet turbine temperature is counteracted by a corresponding decrease due to the air extraction from the high-p compressor. In this paper, a previous model published by De Paepe & Dick is revisited and extended: while the original model consi...

The heating capacity and coefficient of performance (COP) of conventional air-source heat pumps decreases towards lower ambient temperatures. In addition, high discharge temperature at the compressor discharge might limit the operation of the heat pump at very low ambient temperatures. Oil injected into the compression chamber at the beginning of the compression process can absorb part of the h...

R1234yf is a synthetic HFO refrigerant co-developed as replacement for R134a in automotive air conditioning applications. Thus, this study, alternatives to the that were removed from newly produced devices examined. The performance of cooling processes and R744 gases was compared with R134a. A simulation model first developed. This validated experimental results. Analysis conducted both heating...

The objective of this study is to design and briefly investigate the cooling performances of an air conditioning system for a special purpose vehicle under various experimental conditions. An air conditioning system with two parallel refrigeration cycles consisting of two compressors and two condensers for satisfying the required cooling performance of the special purpose vehicle was tested und...