Wheel selection for heat and energy recovery in simple HVAC ventilation design problems

This paper shows how air-to-air heat and energy system design problems can be formulated for a simple HVAC configuration and solved for the least life-cycle cost system while still retaining a small payback period. Mathematical expressions and design tables are presented to facilitate the design process. The design process is illustrated for the city of Chicago where both large heating and cooling loads occur in HVAC applications. The example design problem presented shows that
payback periods of less than one year are often achieved for energy wheels and sometimes for sensible heat exchangers.
The life-cycle cost savings for auxiliary heating and cooling ventilation air far exceeds the capital cost of the energy exchanger (sensible or total), even when only a ten-year life cycle is considered.