Power use of compressor frig

[booster]

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.

[mkguitar]

what brand/model? just so I know.

those are dandy results and with cooler ambient temps not only less load on the fridge, but the panel should work better.

Mike

[markopolo]

Batteries fully recovered everyday in 4 hours or so of full sun plus maybe 2 hours early morning partial/limited sun. 5 hours of daylight (this time of year) to spare is a nice cushion

[wincrasher]

I already have my panels to mount on my new van when it arrives. I'm thinking having 260 watts will give enough of a margin for shadows, weaker sun, etc, to keep ahead of the fridge and modest loads I expect.

[gregmchugh]

Wincrasher, what model compressor fridge is Winnebago using in the Travato?

[wincrasher]

It's a Nova Kool in the K (the G is using a 3 way Dometic 5.0 cu ft). Not sure the model number, but it's 4.3 cu ft. Believe some have said the consumption is 45 watts - if anyone knows the true figure, please chime in.

[gregmchugh]

Very good, NovaKool seems to be a very reliable unit compared to other options. Probably a R4500 model, here are the models...

http://www.novakool.com/documents/sp...alJuly2015.pdf

[Davydd]

We have the RFU6800 Novakool that runs at 5.2vdc at 12v. That's considerably more than the 3 cf model at 2.2vdc. We just got back from Advanced RV where we had more insulation added to the refrigerator surround and more powerful ventilation. It seems to keep cooler and run less now. ARV upgraded a few things for us to their current designs in a three day stay over.

[gregmchugh]

The R4500 4.3 cu ft is in the middle with 4.4 amps at 12v.

Davyyd, I noticed you mentioned you had some repairs done while at Advanced RV, care to share what repairs were needed?

[booster]

Originally Posted by mkguitar

what brand/model? just so I know.

those are dandy results and with cooler ambient temps not only less load on the fridge, but the panel should work better.

Mike

Ours is an Isotherm Cruise 85. Although it works well, we had a lot of issues getting it to work right because it is setup for boats, taking inside are from the floor and putting it back at the top of the frig. Ours vents to the outside of the van, so the airflow was all backwards and required some ducting to straighten it out. The units with the condensers on the back would work better for outside venting.

When I put the frig in, I added two layers of polyurethane insulation board wherever it would fit on the top, back and sides, so that certainly must help.

[Davydd]

Originally Posted by gregmchugh

The R4500 4.3 cu ft is in the middle with 4.4 amps at 12v.

Davyyd, I noticed you mentioned you had some repairs done while at Advanced RV, care to share what repairs were needed?

Probably a topic for Advancing Alvar but it was a lot of stuff including my nerf bar step crunch with a high curb. I'm just glad I didn't have fiberglass skirts.

[gregmchugh]

Know what you mean, I just scraped the rear passenger side skirt on a low rock I missed seeing on a tight turn into a campground. No more fancy low hanging skirts on our next van.