DDW,

you hit the nail on the head when you talked about stuff going in and out of the unit!

We built up our system in the San Francisco Bay area. We also used vacuum panels ( photo at bottom). I then used 4, 32 Watt solar panels. That would cover our use just fine, even at the hottest times. I thought that would cover us as we moved south as I expected to get more sun in the mid lats.

When we were in the Sea of Cortez, during the summer (VERY HOT!) they did NOT cover the system requirements!

For an experiment, during the heat of summer, we did not open the unit for 3 days. The solar panels once more took care of of it no problem. BUT, even though I normally drink room temp water, that was not possible in the Sea when “room temperature” is over 95, the solar panels were not enough. I kept a short log and we were moving over 2 gallons of water (plus food) in and out of the unit, just for drinking!

That is why when I look at a unit to install, the R value is very important, but NOT the only item to look at! Power usage is my number 2 item.

During our 2ed year in the Sea, they came out with the newer Engle units that draw 2.5. If I had had our unit on a shelf, it would not have taken me one hot second to get a new unit and replace the old unit. But with a built in unit, I did not have that option.

Just sayen........

Greg