Performance charts for convective heat exchangers

Methods are given for the preparation and use of charts which present the thermal performance of convective heat exchangers for HVAC applications. Performance is expressed by the relationship between three parameters: the air-side and water-side effectivenesses and a design parameter representing the heat-transfer characteristics. These incorporate the effect of varying air velocity on the rate of heat transfer. Typical charts are illustrated for counterflow heat exchangers with one, two or three tube rows. Examples are given showing the utility of the charts as a practical aid to design and to the development of heat exchangers for novel operating conditions.