Long time lurker here & some of you guys/gals have great insight and have been doing this gig longer than I. I finnaly came across a pre-historic 40 ton double-duct / hot & cold deck, air-cooled built up system from i think the 1970's, it serves a big retail store..anyway it used to be R12 but someone converted it to "Hotshot". I was just wondering if any of you all ever converted out of Hotshot into something else like R22? I may need to replace the evaporator( it's around 40 yrs. old & may be leaking ) and condensor. I'd like to maybe keep the Hotshot because there is over 200lbs. of it in this system.