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1. Homework Statement
Coefficient of performance of a refrigerator is 1.4
A faulty 20w bulb remains on when the fridge is closed.
Under normal circumstances, the bulb turns on when the fridge is open. The door is opened 20 times a day for 30 seconds.
Calculate the increase in energy consumption in 1 year.
2. Homework Equations
Coefficient of performance = heat extracted from cold reservoir Qc/work delivered to pump W
COP = Qc/W
3. The Attempt at a Solution
This is where I am stuck, the work done by a compressor is not given, a bulb doesn't relate to the COP? Here's my attempt:
P=20w, under normal operation, T= 30x20x365 s therefor total energy in a year is 20x219x10^3 = 4.38x10^6 J
Under faulty conditions: P=20w, T= 31.536x10^6 s therefor total energy = 20T = 630.7x10^6 J
Increase in energy = 630.7x10^6 J - 4.38x10^6 J = 626.3x10^6 J
Coefficient of performance of a refrigerator is 1.4
A faulty 20w bulb remains on when the fridge is closed.
Under normal circumstances, the bulb turns on when the fridge is open. The door is opened 20 times a day for 30 seconds.
Calculate the increase in energy consumption in 1 year.
2. Homework Equations
Coefficient of performance = heat extracted from cold reservoir Qc/work delivered to pump W
COP = Qc/W
3. The Attempt at a Solution
This is where I am stuck, the work done by a compressor is not given, a bulb doesn't relate to the COP? Here's my attempt:
P=20w, under normal operation, T= 30x20x365 s therefor total energy in a year is 20x219x10^3 = 4.38x10^6 J
Under faulty conditions: P=20w, T= 31.536x10^6 s therefor total energy = 20T = 630.7x10^6 J
Increase in energy = 630.7x10^6 J - 4.38x10^6 J = 626.3x10^6 J