'Development of New Refrigerant for Air-Conditioning System'

Ozone depletion and global warming or more accurately climate change are major
environmental concerns with serious implications for the future development of the
refrigerant based industries. The industry has reacted to reduce ozone depletion but the
follow-on consequences of trying to react to the need to reduce the emission of
greenhouse gasses. Consequent upon the Montreal Protocol and its adjustments came to
measure to reduce the production and use of materials with high ozone depletion
potentials. First, the halons were banned, then the chlorofluorocarbons (CFCs) and now
there's a push to ban the hydrochlorofluorocarbon (HCFCs) on a time scale which
becomes shorter with each new amendments to the protocol.
The rush for developing new refrigerant working fluid is at peak now considering the
impact on ozone depletion, global warming, economics safety and efficiency.
In this study, six potential refrigerant working fluids are investigated based on the
enthalpy of solution and the pH using calorimetry method.
Sodium chlorate ofmolaltiy 5.637 mol/kg is the most suitable refrigerant for the new air
conditioning system using the membrane technology. The l5°C temperature decrement
of the solution provides a large driving force for heat transfer from ambient to the
endothermic salt solution. Experiment results shows that in a well insulated system, the
endothermic salt solution could provide cooling of hot air to l8°C - 20°C for up to 50
minutes.
Sodium chlorate is also non-toxic as compared to Freon-22, highly stable and do not
corrode copper coils. This eliminates the waste treatment required by Freon-22.