Obviously, as we increase the system head pressure, we also increase the compression ratio of the high-stage compressors. This directly translates to an increase in the amount of work the compressors must perform (i.e., greater horsepower requirements and greater energy consumption).
We will begin this discussion by examining exactly how much impact raising the system head pressure has on compressor kilowatt usage. By observing the operation of two different types of compressors — reciprocating and rotary screw — we can see the relative effect in both cases. Next, we will investigate the factors involved with system head pressure and will find that the primary component of concern is the condenser. By focusing on the requirements for efficient condenser operation, we can identify potential problems that lead to poor condenser performance.