We have a 40 year old Lennox that is still working but is wearing out; doesn't put out cold air even with a fresh recharge, etc., and (obviously) isn't nearly as efficient as new models. I have read where a/c units will have to conform to higher efficiency standards that will add 25% or more to the price. So it's time to look for the season end deals but I don't where to look for comparisons. Consumer Reports just lists window type a/c, for example, but does anyone know websites that I might check? Also, I've gotten and ad for Sears Kenmore units; who makes those and what do you all recommend from personal use? Thanks.