Can the Efficiency Be Greater Than One?

This is one of the perennial top search terms for this blog. Anticlimactic answer: Yes, because input and output are determined also by economics, not only by physics. Often readers search for the efficiency of a refrigerator. Its efficiency, the ratio of output and input energies, is greater than 1 because the ambient energy is … Continue reading Can the Efficiency Be Greater Than One?

Consequences of the Second Law of Thermodynamics

Why a Carnot process using a Van der Waals gas -ย or other fluid with uncommon equation of state -ย also runs at Carnot's efficiency. Textbooks often refer to an ideal gas when introducing Carnot's cycle - it's easy to calculate heat energies and work in this case. Perhaps this might imply that not only must the … Continue reading Consequences of the Second Law of Thermodynamics

An Efficiency Greater Than 1?

No, my next project is not building a Perpetuum Mobile. Sometimes I mull upon definitions of performance indicators. It seems straight-forward that the efficiency of a wood log or oil burner is smaller than 1 - if combustion is not perfect you will never be able to turn the caloric value into heat, due to … Continue reading An Efficiency Greater Than 1?