ARB Transit Bag - Insulating Study and Findings

[Dissent]

I pondered buying a Transit Bag for my ARB 50 for it's insulating properties but can't justify the price without any solid feedback on whether the insulation would affect the fridge. I borrowed a transit bag for a week and was surprised that it didn't affect the temperature at all. The temp, the swings (high and low) and the duration between compressor cycles didn't change at all.

I used a Bluetooth SensorPush thermometer wire tied loosely to the top of the separator in the main compartment. I've measured the temps for 5 days including times with the bag on and bag off, sitting in the sun and sitting in the garage. No difference at all.

I have my fridge set to 35 degrees with a 4 degree offset to get it close to actual readings inside.

Sitting in the garage, plugged into 110v power with all 4 windows down, I saw very consistent fluctuations from 30.8 to 32.9 averaging 31.8 between 2:00pm and 5:00pm in the ambient 107 degree heat. Complete high/low cycles took 30 minutes on average.

Sitting in the parking lot in direct sun, with a 4x windows cracked 1" on my 80 series, I saw very consistent fluctuations from 30.0 to 32.1 averaging 31.1 between 2:00pm and 5:00pm in the ambient 107 degree heat. Complete high/low cycles took 30 minutes on average.

 

[Enigma]

Some of the guys in my club have made their own "jackets". Can't recall what the material was exactly or what (if any) differences they noticed. This was quite awhile ago but might have some info buried in the CC section.

 

[bluesquirrel]

The only thing I could see one of these insulating jackets doing is delaying the inevitable heat soak of the fridge exterior. Depending on the material, some may work better than others. For instance a reflective jacket under direct sunlight.

 

[offroadvegan]

I bought my transit bag mostly to protect the fridge in the 80.

 

[Dissent]

I suspect most people buy the Transit Bag for just that...protection during transit. I've seen many people make their own from foil covered bubble wrap called Reflectex which always intrigued me so when I picked up the ARB, I figured that's why they make their own cover. Not sure why people make their own covers now...

 

[george_tlc]

The real measure of adding external insulation is how it affects overall power consumption over a period of time (I would think a minimum of 24 hours). Of course you would need 2 identical fridges with identical contents in identical external thermal conditions. Then measure the 24 hour power draw (amp.hours is fine) from the same battery of each unit.

When I bought an arb 50qt in oz I asked for (and received) a free transit bag as part of the 'deal'. Not like they aren't making significant profit on the fridge itself...

cheers,
george.

 

[John McVicker]

I don't really see how the transit bag could not help in what George is describing. It's not going to get any cooler, what one sets the temp at is what you will see. But the compressor 'should' be on less time with the transit bag...less overall draw. Maybe not...but I would think so.

 

[Dissent]

Those are good points and I would have loved to have a very definitive study and result on the power consumption but given the transit bag is $125 and I paid $0 for the fridge...I'm not getting one.

 

[Cruiserdrew]

I made a cover for mine from roofing "radient barrier" since we had a whole roll left over after a new roof was put on our house. It's basically foil/foam/foil. I don't have any data, but I *think* that it has significantly cut power use. And since it was free, I'm good with it. I even double layered my older (and less efficient) fridge and I think it runs significantly less when camping. Anyway, at least put a reflective bubble wrap barrier on the lid of the fridge if the sun can ever shine directly on it.

 

[Corbet]

While I’ve never done a scientific test I can say with confidence the transit bag on my Engel makes a difference. By a 1/2 to full day on my truck battery. Maybe it’s the steel case of the Engel verse plastic of the ARB.