New Peak Moisture Design Data in the 1997 ASHRAE Handbook of Fundamentals

Abstract

Chapter 26 of the 1997 edition of the Handbook of Fundamentals published by ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) contains climatic design data that has been completely revised, recalculated and expanded. Designers of air conditioning systems for hot and humid climates will be pleased to note that, for the first time, the chapter contains values for peak moisture conditions. This is in sharp contrast to older editions, which contained only the average moisture during periods of peak dry bulb temperatures. The new data show that using earlier, temperature-based data for humidity design underestimates the true peak moisture loads by 30 to 50% depending on the humidity control level in the space. This paper explains the new data elements and suggests some of its potential implications for engineers designing air conditioning systems for hot and humid climates.