I tried a couple of things today, not sure how much they helped but it was relatively cheap to do.
I put DEI Reflecta Cool sheeting on the evaporator housing and pipe insulation on the metal parts of the cold side of the ac hoses.
Don't have test data to say whether it worked or not, just that it was 90 degrees with a heat index of 104 today and it was cool as cucumber inside the BII. I don't see it helping much even in a best case scenario, but little bits of improvement add up.
What I expect the DEI sheeting to help with is keeping the heat from the engine compartment from heating up the evap housing. There was a strip of insulation on the housing that was in real bad shape down low by the exhaust. Same thing with the pipe insulation, to stop heat transfer to the suction lines. Also to stop condensation on the lines, there's no need for random water sources under the hood.
I also insulated the heater hoses where they pass over the evap housing. I keep thinking about bypassing them for the summer months to keep the heater core from heating up the vent system. I think there used be a mechanical valve on some cars just for this in the way-back days.
