Extension of the enhanced Thorp method beyond conventional water chilling machines operating normally

The well-known Thorp method of verifying surveys of performance of water chilling machines has been extended and termed the 'inexact Thorp method' for use both with conventional machines where auxiliary devices are operating, and with custom-built non-conventional machines, employing, for example, single or multiple screw compressors. This inexact method cannot conclusively verify the apparent performance, but it does not indicate either the relative likelihood of this being acceptably accurate, or the presence of unacceptable errors and where these may be. It may also be feasible to determine the range in which the true COP attained by the machine must lie. Three case studies illustrate the use of this inexact method.