I bought my house brand new in 2005. The builder put in an AC unit that was too small for the house. We have had problems with the unit every summer since. Our compressor finally went out on Tuesday. We had a guy who owns his own company come out and tell us that he'd put us in a 2.5 ton unit (which is a half ton larger than what we had before) for $. This is a used unit and only builders grade (which we knew). The problem is that it's not working as well as our previous 2 ton unit. It ran all night last night and has been on all day today. We had someone from Home Depot come out this morning and he actually told us the unit this guy sold us was a 2 ton and not a 2.5 as he claimed. I've called the guy and let him know it's just not cooling the house and he's supposed to be coming over this evening. Is there any way I can determine myself if it's a 2 ton or a 2.5?