In detailed mode,  I am modeling a central plant for a customer in TN.  I am looking at adding a VFD chiller vs. a new plate & frame heat exchanger for Dec-Feb. free cooling.  I am creating a process tower load and changing loop temperatures based on schedules for plate & frame option.  Chillers are completely off December 1st - end of February.  So end of Feb, I turn on chillers and the demand for that month is higher than August.  My Feb. chiller process load is only about 35% of the August process load.

This same thing happened to another model I did where the customer completely turns his chillers Dec-Feb.  I scheduled chillers off for these months then turned on March 1st.  March demand was about 25% high in March than in August.  Any suggestions would be greatly appreciated.