I agree with Big Mal's finding - poor insulation, poor air flow.
When we had our Eagle camper, I removed the fridge for "repair" by a specialist here in Townsville. We had a sorry trip home from Cairns & the fridge performed poorly. There was no fault found with it after a week sitting on an open bench. I had also contacted the manufacturer who sent me some drawings of the correct installation - there was no comparison between what I had & what was supposed to be there but a major issue is the lack of room that is made available by the caravan manufacturers. While I couldn't lift the bench top at least 6", I did as I mentioned earlier - fitted a blow & a suck fan to get rid of the heat. That made a lot of difference.
However, on our Discovery Pop-top, there is no room to add the fans & touch wood, the fridge is working perfectly so far. I do shade the side of the van when it's in the sun of an afternoon.
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Warren
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If you don't get it done today, there's always tomorrow!
A little like your situation, full rectification of the installation to manufacturer's recommendation is not possible on mine. Mainly the top vent of mine should be higher. But I made improvements and it is now working fine.
Apart from fans, the size and position of the vents is important. Sealing the top and sides to prevent hot air around is important. And a baffle to ensure airflow actually passes through the cooling fans.
Unless the insulation is checked and improved, on most vans the fridge, no matter what its operation won't be working to its best ..................
I have modded probably 6 vans now as friends stop by with poor fridges, even compressor jobs, on all of them, even new ones the instalation has been poor, once the insulation is sorted then a dedicated 12v supply from tug using at minimum 8 B&S cable with an anderson at each end, the Anderson at the fridge end makes a good step down to the fridge wiring, it can also be used as a 12v extenstion lead for back of rig ...... just fitting fans and screens isn't getting to the root of the problem ...
Recently replaced my 12 yr old 3 way and while a compressor was about the same price I would have had to add another battery to cover its operation, went a new 3 way less hassle.
A simple test is to feel the surrounds of the fridge when its in use, cupboards and outer wall hotter than other areas means it is poorly insulated ..........
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Checking out the places I drove past a thousand times................
I have modded probably 6 vans now as friends stop by with poor fridges, even compressor jobs, on all of them, even new ones the instalation has been poor...
A simple test is to feel the surrounds of the fridge when its in use, cupboards and outer wall hotter than other areas means it is poorly insulated ..........
Extra fridge insulation wattage test:
https://thegreynomads.activeboard.com/t65059593
0.0140 kW/h The uncovered fridge.
0.0132 kW/h Standard cover.
0.0116 kW/h 30mm XPS foam.
0.0082 kW/h 60mm XPS foam.
I have very limited space in the car for batteries, two of the three 26ah batteries (4 batteries since 2019) shoehorned under the seat, so I did some tests on the 28L Waeco going in the car so it would use the least amount of power possible. 28L is the largest fridge I could fit without taking over.
I heated a bedroom in the house for about 3 days to 35°C with three heaters (pretty horrendous electricity consumption) & tested the fridge with different levels of insulation. I also installed a very efficient Noctua fan in the fridge from an old computer. Put a baffle around the fan as well, as the fridge design was recirculating hot air. Added velcro as hot air was traveling up between the fridge & cover reducing thermal efficiency. With foam sleeping mats added efficiency is better than 30mm of XPS foam but I didn't have accurate figures.
28 litre fridge per hour, ambient 35°C, fridge set at +2°C
It doesn't matter what type of fridge, as long as it doesn't have condenser tubes in the walls of the fridge.
Just add extra insulation, bubble wrap will do. Add as many layers as possible. Do the door as well.
Test set-up:
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Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.
That interesting data @Whenarewethere, when I had my Colorado with an alloy shed on the back the Engel was really having a hard time so i fitted a 12v computer fan on the back wall and a vent on the front, the vent dropped the temp quite a lot as I went down the road, it was fitted just as a test but ended up permanent as the position I had fitted it didn't get rain or dust in so i left it, the fan I would just flick a switch and it would run while parked up, the internal temps where a lot lower and the Engel didn't run continuously as before, I also made a insulated jacket for it and lined the inside of the shed ...........
Son fitted his fridge under his ute lid, told him do some fans/vents, first trip away it killed the battery in a short time as no air flow, he was doing the Madigan, "I should have listened to you Dad," shock horror at those words I can tell you, he must be getting old...lol,lol.....
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Checking out the places I drove past a thousand times................
I wanted to get a thorough understanding of the fridge's requirements. So was around the clock writing down data. Have pages & pages.
We didn't have room for more batteries. In the end stuffed multiple foam 10mm sleeping mats inside the cover. Also covered the lid & a bit of foam under the boot floor where the fridge normally sits. Surprising the amount of cold that drops out the bottom of the fridge as insulation is too thin.
Basically stuff foam everywhere. We also chuck doona, sleeping bag or towels or anything thermal over the fridge during the day. Making sure vents have free air flow.
Also leave windows open a whisker to get airflow through the car. Use sunscreens on the sunny side of the car, cut to size for every window.
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Procrastination, mankind's greatest labour saving device!
50L custom fuel rack 6x20W 100/20mppt 4x26Ah gel 28L super insulated fridge TPMS 3 ARB compressors heatsink fan cooled 4L tank aftercooler Air/water OCD cleaning 4 stage car acoustic insulation.