Due to the detrimental environmental consequences of synthetic refrigerants, natural refrigerants have gained renewed interest as alternative for a variety applications due their minimal ozone depletion potential (ODP) and insignificant global warming (GWP). This study compares performance characteristics R32-based Air Source Heat Pump (ASHP) those R290 R410A refrigerants. In this study, analys...

As the concern for a global energy conservation and environmental protection are increased, it became more important thing to correspond with CFC depletion. Many companies have produced CFC-free refrigerators using alternatives refrigerants. Alternative refrigerants have merit such as global warming effect, but also have demerits such as lower efficiency, miscibility, increasing noise and poor ...

Modern lifestyle, industrialization and economy thrive on energy which is getting expensive overtime. Thermosyphon based systems are getting attraction for their promising heat transfer efficiency and zero energy utilization. Refrigerants having ozone depletion potential (ODP) and high Global Warming Potential (GWP) have been banned or under time bared permission under Montreal (1987) and Kyoto...

In residential heat pump systems, the motivation for secondary loop systems is to allow for the use of flammable or toxic refrigerants with lower global warming potentials than the currently employed HFC refrigerants. The addition of radiant panels as integral building components (embedded in concrete at construction or attached to the underside of wood flooring) is becoming more common. Combin...

In the present study, the flow boiling heat transfer of R1234ze(E), R32 and zeotropic mixture R1234ze(E)/R32 (50/50 mass%) in a horizontal micro-fin tube is experimentally investigated to clarify the pressure drop and heat transfer characteristics. Tested micro-fin tube is made of copper, and its geometry is as follows, 6.00 mm in outer diameter, 5.21 mm in mean inside diameter, 0.26 mm in fin ...

As one of the earliest natural refrigerants, CO2 has a lot of unique advantages, such as zero ODP, negligible GWP, excellent heat transfer coefficient, high volumetric capacity, non-toxicity, non-flammability, and cost effectiveness. Since it was proposed to applying in the mobile air-conditioning, the transcritical CO2 cycle has been attracting great attentions to replace CFC and HCFC refriger...

Title of Document: INVESTIGATION OF HOUSEHOLD REFRIGERATOR WITH ALTERNATIVE LOW GLOBAL WARMING POTENTIAL REFRIGERANTS Daniel Thomas Leighton, Master of Science, 2011 Directed By: Professor Reinhard Radermacher, Mechanical Engineering Steady-state and transient thermodynamic models of the refrigeration system were created in order to predict the performance of household refrigerators using diffe...

The observation of a giant magnetocaloric effect in Gd5Ge1.9Si2Fe0.1 has stimulated the magnetocaloric research in the last two decades. However, the high price of Gd and its proclivity to corrosion of these compounds have prevented their commercial use. To reduce raw materials cost, transition metal-based alloys are investigated to replace rare earth-based materials. Environmental consideratio...

Many fluids of hydrocarbon derivatives were used as working fluids in refrigeration and air conditioning during the past few decades. The phase out of chlorofluorocarbons and hydrochlorofluorocarbons has initiated research on finding an alternative working fluid for the existing. In this article, some working fluids with zero ozone depletion potential have been assessed for their suitability as...