ok i am trying to figure out what seer and if my current unit is a 2 ton or 2.5 ton system. I need to purchase a a-coil to get my central air up and running again. On the outside unit everything is all sun faded and very difficult to read. The info i have found off of the unit is it is a HEIL model #NAC3030A2A1 serial#L941971603. any help figuring out if this is a 2.5 ton unit and the seer and any other info on it would be greatly appreciated. ty in advance for your help.