I just joined the forum because I am an engineer and I find HVAC a very interesting topic. Anyway, since I moved into this house 20 years ago, this General Electric 2-1/2 ton AC has never broken down except for needing a couple cans of freon every 3 or 4 years. Based on the sticker on my furnace, it was installed in 1971. 37 years ago!!! As far as I can tell this thing has another 20 years in it. I have no idea what the seer rating is or if seer was even invented back then. Do you guys know if the old GE units are some sort of legend. I posted a couple of photos. Thanks.