ABSTRACT
Section 3.6 outlines the Lorenz cycle and its potential for improved efficiency under properly selected operating conditions. These occur in a heat pump application when there is a large and approximately equal temperature glide in condenser and evaporator and a temperature lift that is as small as possible as compared to the glide. One such application is air-conditioning, where for most operating hours the air temperatures inside and outside a building are essentially equal. An ARI Standard 210/240 (1994) specifies the return air temperature in a building as 26.7°C and the outdoor temperature as 27.8°C. In order to ensure adequate dehumidification, the air supplied to the inhabited space must be cooled to about 12.8°C. Thus, the temperature glide in the evaporator is 14 K. Accordingly, the temperature glide in the condenser should be at least 14 K or even more as described in Section 3.8; here it is chosen to be 19 K. Figures 3.8.1 and 3.8.2 show a schematic of the temperature conditions involved.
