We finally got the "opportunity" to see how the Isotherm 3cf compressor frig worked in hot weather and sun. We spent 6 days without moving in Zion National park in a site that put the frig side of the van, with the vents for the frig, facing dead on south. It was in a cavern and had some small trees to the east and west, so we got full sun from about 9:30am to 5:00pm. Highs were 93-98*F without clouds. We had the Fantastic fan on med/low most of the day, and usually watched a couple of hours of DVD each night. Often a charge cycle of the laptop and tablet. We did not run the engine at all and the solar was able to get us full every day, so we were able to use the solar recovery as an accurate reading of daily use. It was normal to be down 20-25ah in the morning and fully recovered by 1-2pm.
Surprisingly, we did not have any days that we were over 50ah of use, which was a real surprise with the heat and frig, which held an extremely stable 38/39*F. It would appear the frig was under 30ah per day in the extreme heat, so we will take that. I had guessed it would be over 40ah under those conditions for the frig.
I guess it kind of confirms what folks have said, basically that a single 100 watt panel would just keep up to balance a compressor frig, in very good sun, in hot weather. 200 watts is probably a better standard, for the real world, however.
Of course our happiness with the frig went south about a week later, when the thermostat went crazy in the frig, requiring continual adjustment and 3 range calibrations. This is the second one to fail, with the first within the first year.
All and all, very happy with the ability to stay off shore power essentially indefinitely, with relatively low sun in late Sept, but were pretty far south. Having the frig not break the power bank, so to speak, was a pleasant surprise.
Surprisingly, we did not have any days that we were over 50ah of use, which was a real surprise with the heat and frig, which held an extremely stable 38/39*F. It would appear the frig was under 30ah per day in the extreme heat, so we will take that. I had guessed it would be over 40ah under those conditions for the frig.
I guess it kind of confirms what folks have said, basically that a single 100 watt panel would just keep up to balance a compressor frig, in very good sun, in hot weather. 200 watts is probably a better standard, for the real world, however.
Of course our happiness with the frig went south about a week later, when the thermostat went crazy in the frig, requiring continual adjustment and 3 range calibrations. This is the second one to fail, with the first within the first year.
All and all, very happy with the ability to stay off shore power essentially indefinitely, with relatively low sun in late Sept, but were pretty far south. Having the frig not break the power bank, so to speak, was a pleasant surprise.
