Do you have the model number so that I can properly address the info you require?
I just purchased the unit this past winter. The unit is an gas infinity 80....the ac unit is an infinity 2 stage a/c unit. The controller is an infinity control. I wanted to adjust the fan during the cool cycle.....they adjusted it today to have the fan output from 700cfm to 800 cfm when it is in the high/maximum cooling mode....but i and would like to adjust it for the efficiency mode and also I would like to enable the fan progam mode which all have to be done from the thermostats technician mode which I cannot access.
Here is a link to the installation manual that should tell you how to enter the menu you want starting at the bottom of page 7.
Please read the next few pages after page 7 and I believe you will find the way to set the fan for efficiency mode.
Hope this helps you and if you need any further info in this matter I will still be able to assist you even after you have clicked the Accept button and positive feedback is always appreciated.
Good Luck! Rick in Texas