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I'll throw my .02 cents in here...
About 10 years ago the 12/120/LP fridge in my RV gave up the ghost. It was going to be about $1000 to replace it, so I went to a local appliance store and bought a regular apartment sized fridge right off the showroom floor. Another stop to an automotive store scored me an off the shelf 400W inverter and a deep cycle battery along with a battery isolator.

After installing it all, I found I could get 3 solid days of run time before the inverter would start beeping from a low battery. Overall I was quite happy with it, but I set out to improve the performance. I punched 2 small holes in the wall behind the fridge and installed 2 fans from desktop computers. They run off straight 12V. One hole was down low to draw air into the cavity behind the fridge, the other up high to draw the hot air out. I cut up a 1" piece of construction styrofoam insulation panel and slipped it between the coils and the back of the fridge leaving about a 3/4 gap between the coils and fridge body, then filled in all the gaps around and on top of the fridge using 4 cans of spray foam insulation. About 3" thick on the top and about 1-2" on each side.

After adding the cooling fans and extra insulation, I was getting 5 days of run time on a single charge. This was all in the summer months. I took one trip in it to Atlanta to attend a funeral in the winter months and it ran for 7 solid days without beeping for a low battery.

I've since sold that RV, and too much time has passed for me to remember name brands, but the moral of the story is that it's worth the effort to increase efficiency by adding insulation whenever practical and making sure the coils have sufficient air flow.
 
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Darryl Roederer wrote:I'll throw my .02 cents in here...
About 10 years ago the 12/120/LP fridge in my RV gave up the ghost. It was going to be about $1000 to replace it, so I went to a local appliance store and bought a regular apartment sized fridge right off the showroom floor. Another stop to an automotive store scored me an off the shelf 400W inverter and a deep cycle battery along with a battery isolator.

After installing it all, I found I could get 3 solid days of run time before the inverter would start beeping from a low battery. Overall I was quite happy with it, but I set out to improve the performance. I punched 2 small holes in the wall behind the fridge and installed 2 fans from desktop computers. They run off straight 12V. One hole was down low to draw air into the cavity behind the fridge, the other up high to draw the hot air out. I cut up a 1" piece of construction styrofoam insulation panel and slipped it between the coils and the back of the fridge leaving about a 3/4 gap between the coils and fridge body, then filled in all the gaps around and on top of the fridge using 4 cans of spray foam insulation. About 3" thick on the top and about 1-2" on each side.

After adding the cooling fans and extra insulation, I was getting 5 days of run time on a single charge. This was all in the summer months. I took one trip in it to Atlanta to attend a funeral in the winter months and it ran for 7 solid days without beeping for a low battery.

I've since sold that RV, and too much time has passed for me to remember name brands, but the moral of the story is that it's worth the effort to increase efficiency by adding insulation whenever practical and making sure the coils have sufficient air flow.



Very good! The only comment I would make, is that the new batch of fridges seem to have the coil that used to sit on the back of the fridge inside the panel. I am not sure where the warm coil is now, it may still be at the back, but could just as easily be at the sides where there is more likely to be cooler air in the average kitchen. I have noticed that using the top of my fridge to keep things warm (starter, kefer, etc) doesn't work with our newer fridge (Maybe 5 years old?). It would still be worth venting the space behind the fridge (but not the compressor itself) I think, but to isolate the coil would mean taking things apart.

 
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