a system for self - configuring complex hvac systems has each of several units provided with a microprocessor control . the several units are each available in various optional styles , sizes , etc . the microprocessors provide information to a central control of the particular characteristic of the particular unit . thus , when the hvac system is initially assembled , the microprocessors associated with the individual units report these characteristics to the control . the control then determines the characteristics of each of the individual units , and accesses control strategies for the combination of individual units that are being utilized in the particular hvac system .