At 1AirConditioning.com we never charge a core deposit on any of our AC products. Core charges are paid back once the old unit is returned, this process can take a long time and its never certain the core charge is going to be returned at all. Most AC suppliers will charge a core as an incentive for the customer to send back to old part.  Without a core deposit you keep more of your money and never have to worry about sending back the old part.