If you charge to clear glass with a 65 degree box and then valves throttle down as box reaches temp you're going to stack.liquid and.end.up with high receiver level. My experience may come from 120-130 rooftops in summer and 30's in coldest winter but this is what works for us. Of course you have to have clear sight glass that is not what is being debated just how we get to the same end result.