Right now I am using Energy Plus. I am just conducting a simple experience of 'Steady State' where I use 'No Weather File' and simulate the program with the 'SizingPeriod:DesignDay". Right now, I am only considering the 'Winter' for the steady-state condition. While I found ways to control the outside temperature, the spreadsheet is fixed at 20 Celsius for 'Zone Air Temperature'. Is there any way to change that '20 Celsius Zone Air Temperature'?