# Average Rate of Heat Gain in Fridge

by Jacob87411
Tags: average, fridge, gain, heat, rate
 Sci Advisor PF Gold P: 2,248 Average Rate of Heat Gain in Fridge All you need is the average power consumption of the refrigerator, the temperature of the refrigeration compartment, and ambient temp. If you approximate the refrigerator as a Carnot Vapor Refigeration Cycle, you can calculate the coefficient of performance using just the temps: $$\beta_{max}=\frac{T_{c}}{T_{h}-T_{c}}$$ and using the coefficient of performance and the power input (with an efficiency for the the compressor, maybe 80%), the heat gain is calculated as: $$\dot{Q}_{in}=\beta_{max}*\frac{\dot{W}_{c}}{\eta}$$ So for a refrigerator holding at 35 degrees fahrenheit (275 K) and ambient of 75 degrees fahrenheit (297 K), with an average power consumption of 70 watts (50kWh per month), and assuming the power consumption is mainly from the compressor, the average heat gain would be about 1000 watts if I did the calcs right...