(1) A house has a heat pump with a COP = 2.1. If it requires 2,056 kW · hr of en
ID: 2241704 • Letter: #
Question
(1) A house has a heat pump with a COP = 2.1. If it requires 2,056 kW·hr of energy each month to operate, how much heat is delivered to the house in kW·hr within that month? (ANS: 4317.6 Kwhr)
(2) Refrigerant R134a enters the condenser of a heat pump at 160 psia and 120°F at a rate of 0.42 lbm/s, and leaves at 160 psia and a saturated liquid. If the heat pump's compressor consumes 1.7 hp of power, what is the rate of heat absorption from the outside air in Btu/s? (ANS: 28.85 Btu/s)
I know the answers, im just interested in how to get these answers.
Explanation / Answer
the first answer is the product of COP and 2.056
for the second calculate the enthalpy of the refrigerant at the given conditions
h= 407.627 kJ/kg
out h = 260 .93 KJ/kg both has to be converted to lbs system
multiply this with the mass flow rate .... and subtract the compressors work ..... you will get the answer