Does anyone have an estimate (hopefully based on some data) of the loss of efficiency that occurs if you put the condensing unit on the roof in full sun? I'm wondering how much effort should be put into finding a shady spot for it. Also would it help to shade the unit from full sun (or does the efficiency just depend mostly on the ambient temperature around the unit, so that shading wouldn't help if the surrounding roof air were still as hot)?
If nobody knows this, could you estimate this effect by measuring the temp. drop of the output air (relative to the input air) at different times of day? just wondering.