Can the coefficient of performance of a heat pump be greater than 1?

Less work is required to move heat than for conversion into heat, and because of this, heat pumps, air conditioners and refrigeration systems can have a coefficient of performance greater than one.

Why is it impossible for any system to achieve a 100\% energy efficiency?

Explanation: No machine is free from the effects of gravity, and even with wonderful lubrication, friction always exists. The energy a machine produces is always less than the energy put into it (energy input). That is why 100\% efficiency in machines shall not be possible.

Can a heat pump have a coefficient of performance less than unity?

Relation between COP of Heat Pump and Refrigerator The COP of the refrigerator and air-conditioner can be less than one or greater than one. The above formula also shows that the COP of the heat pump can never be less than one; it is always more than one.

How do you calculate refrigerator COP?

For a refrigerator the coefficient of performance is COP = Qlow/(-W). Details of the calculation: (a) COP = Qlow/(-W). (-W) = Qlow/COP = 120/5 J = 24 J.

Can the coefficient of performance of a refrigerator be less than 1?

Generally, T1 and T2 difference is less than T2 so efficiency is always greater than 1. Hence the correct answer is option (A). Thus, we can say that the COP of the refrigerator and air-conditioner can be less than one or greater than one.

Does a refrigerator violate the second law of thermodynamics?

Refrigerators appear to violate the Second Law of Thermodynamics, but the key reason they do not is because of the work needed as input to the system. They are essentially heat pumps, but work to cool a region instead of heat it.

Can a heat engine ever be 100\% efficient?

Heat engines often operate at around 30\% to 50\% efficiency, due to practical limitations. It is impossible for heat engines to achieve 100\% thermal efficiency () according to the Second law of thermodynamics.

Can the coefficient of performance of a refrigerator be greater than 1?

The coefficient of performance (COP) of refrigeration is always more than 1. Hence option (a) is correct. COP is the ratio of heat extracted from the refrigerator to the work done on the refrigerant. …

What is COP efficiency?

The Co-efficient of performance (COP) is an expression of the efficiency of a heat pump. A given heat pump used for air cooling has a COP = 2. This means that 2 kW of cooling power is achieved for each kW of power consumed by the pump’s compressor. COP is indicated without units.