I think Sunny is saying that with a different column you can use oven temperature at 35c which would not require CO2 cooling.

If there is a setting to not use CO2 until the oven temperature is below 40C or even 35C, then the oven would cool using the room air before the CO2 is turned on and that should lower the CO2 usage. I am not familiar with Empower but I know in Chemstation there is a Cryo Use Temperature which will limit the cryo gas to turning on if the oven is too hot. At least that setting is there for the cooled inlet, not sure about the oven cryo though.