Mainstream economics tends to perceive economic systems in a mechanistic way, which makes it impossible to grasp the notion of the irreversibility of real economic process­es and thus encourages referring to the achievements of thermodynamics.Although economic equivalents of thermodynamic quantities have been discussed for more than a hundred years, a sig­nificant development of thermodynamic techniques of modeling economic phenomena, that could complement standard econometric methods, has not been observed.It seems that a comparative analysis of the course of thermodynamic and business cycles could enhance the understand­ing of the mechanisms underlying business cycles, especially in the context of mutual rela­tions between economy and its environment.The aim of this article is to discuss some simi­larities and differences between economic and thermodynamic systems (heat engines and heat pumps). In particular, the problem of performing positive or negative work by an economy is considered and illustrated by the analysis of statistical data referring to the American and Polish economies.