Energy standards for air-conditioned buildings are starting to be expressed in terms of overall annual energy budgets rather than in the traditional prescriptive form so that designers can have maximum scope for ingenuity in designing energy efficient buildings. The prerequisite for this type of standard is the existence of an accurate yet reasonably simple procedure for predicting the energy consumption of buildings. One of the essential parts of such an energy analysis program for air-conditioned buildings is a calculation procedure to model the performance of air cooling coils over a broad range of operating conditions. There are three possible conditions for the coil: "all wet," "all dry" and "partially wet-partially dry." Thus it is necessary to be able to deal with each of these possible conditions and to be able to determine which conditions will obtain with any given set of air and water inlet conditions.

This paper presents a set of relatively simple algorithms that can be used to predict the performance of a multirow coil with either circular or continuous flat fins. The results of this analytical method were compared with experimental measurements carried out for 8-row and 4-row coils. A brief summary of this comparison is given in this paper; a detailed description of the test facility, test procedures, data reduction techniques and a full report of the test results are presented in Ref 1.