Q$4.$ Short Response:

$4.$a$.$ When selecting a refrigerant for a certain application what qualities would you look for in the refrigerant?

$4.$b$.$ Do you think a heat pump system will be more cost effective in New York or in Miami? Why?

$4.$c$.$ A refrigerant $134-$a refrigerator is to maintain the refrigerated space at $-10C.$ Would you recommend an

evaporator pressure of $0\mathrm{.}12$ or $0\mathrm{.}14$MPa for this system? Why?

$4.$d$.$ A steam power plant with a power output of $150MW$ consumes coal at a rate of $60$Ton$\frac{s}{h}.$ if the heating

value of the coal is $30,000k\frac{J}{k}g,$ determine the overall efficiency of this plant.