Determine the temperature of the outer surface of the evaporator, knowing that it does not vary $($steady state$).(1$ point$)$

Calculate the total contact surface area required between the air in the room and the evaporator to maintain the room temperature at $4\backslash$deg C despite the incoming heat flow.

Calculate the mass of refrigerant that must enter the evaporator each second $($this is the mass flow rate Jm$)."$