ouR escaPOD mods

The back story:  Three days into a month-long trip, our RM-8501 refrigerator died. It had 110V (when plugged in), 12V, and propane. I do know enough to check the basics. :)

After checking every conceivable thing I could, I came to the conclusion that the electronic controls died a sudden death. Since this model is discontinued and I could not even find parts, I came to the conclusion that a replacement was in order. I considered getting another absorption 3-way refrigerator, but had experienced enough problems with the one that I decided to look at high-efficiency AC/DC refrigerators. There are not too many brands out there. I looked on Dometic's site and found the CRX1110 listed for over $1700. That was a non-starter. I continued to look and found a much better price at Boat and RV Accessories. It was significantly less and had free shipping.

It arrived, and the first step was to remove the old refrigerator. I bought a plug for the gas line since I would no longer be using it. It is still there. I left the end visible so leak checks could be done. I unplugged the 120V plug and disconnected the 12V line. I recommend pulling the fuse for the 12V side and turning the breaker off before starting. The hardest part was breaking loose the sealant that had been applied around the rubber seal. I removed the fan from the back as I had a use for it that I will describe later.

While the refrigerator is the same width as the old one, the flange that came with it is a little wider.  I had to do a little cutting to make the opening wide enough. The other difference is the new refrigerator is not as tall since it does not have an eyebrow board that sits above the refrigerator. The controls are on the wall inside. There were two potential ways to handle the gap that would be there. One would be to simply add a filler at the top. I opted for the more complicated route of building a platform to raise the refrigerator so that it was at the top of the opening instead of the bottom. It would have been simpler to go with option 1 as I found that I needed to raise the slanted panel and remove some filler boards. Some pictures which I will post later will make it more clear.

I finally got the refrigerator installed and connected. I re-used the rubber seal. I also added insulation to the compartment and since the compressor and condensor coil are at the top back, in the area where the burner and plumbing for the old refrigerator sat. Since it would still generate heat, I sealed around the top, sides, and bottom so there would not be air moving from inside to outside and the reverse.

First impressions:  This thing cools fast! No more waiting 24 hours for the refrigerator to reach a proper temperature. The down side is more energy use. It is a fraction of the 12V power demand of the RM8501, but it is still significant. I'm glad I did the LiFePO4 battery conversion earlier. I don't need to worry about killing the battery overnight. However, it will mean that there won't be any multi-day boondocking adventures unless I connect my solar panel or fire up the generator to recharge. Still, my use of the Free Piston Sterling Cooler gave me an idea of what the power demand would be like. It is acceptable to me to have the reliability of a compressor refrigerator rather than an absorption refrigerator which failed to cool adequately many times.

Now for some pictures:

Front view of completed installation:

Detail view of support platform below refrigerator:

The stain was ebony with a little gray mixed in. It isn't quite a match, but it is good enough. I finished it with polyurethane spray.

This is a view of the base from the back side. Note the insulation bats around the base and sides. What is not visible is the layers of insulation I put in behind the panels. That was the pink foam from Home Depot cut to fit the spaces. This was finished with ebony stain and polyurethane spray. 

This is a picture of what makes this work. The compressor is tiny as is the condenser and fan when compared with one that would be in a house. It is also variable speed which contributes toward it being energy efficient. I added a thermostat and wired in the fan removed from the old refrigerator. I intended to use the old thermostat, but the start temperature of that was too high. I ordered a new one that starts at 100F and cuts off at 85F. It is wired to the 12V line that supplies the refrigerator, so it is not modifying the refrigerator in any way. I strapped it to the compressor with heavy wire ties that were rated for a higher temperature than I could anticipate the compressor reaching. Note that the top of the compartment had to be raised to allow the unit to slide into place. I did not realize it when I built the platform that this would be needed. I could have saved some work if I had not built the platform but just made a filler for the top end instead. However, having the refrigerator sitting a little bit higher is nice for accessing the interior.

I installed the fan to help exhaust heat from the compartment. It is likely not needed, but it can't hurt. The additional insulation should also help to reduce energy use.  I will likely add insulation to the back of the refrigerator as well below the compressor. 

And, a shot of the inside. 

Unlike the old refrigerator, the controls are built into a panel on the inside with no wires or controls to have moisture intrude. The lighting is LED. The freezer is different in that it opens from the bottom up intead of the top down and the compartment is not removable. The freezer does work very well and should be suitable for ice cream and any other items that need to stay frozen. The shelves go all the way to the back and have a lip on both the front and back to help keep things in place. The crisper bins are rectangular and not rounded like the old refrigerator. They are not on a track so they can be removed and replaced easily. The shelves are deeper as well and will allow for larger items to fit. The door shelves are not as wide though. The bottom shelf is deep enough but the top two shelves are narrow. They can be removed, but they can't be adjusted since there are not other mounting points. Still, the deeper shelves are a huge plus over the old one and there are no intruding fins in ether the refrigerator or freezer compartments.

The refrigerator comes with a two year warranty. I expect it to be reliable and I should not have any issues with it keeping the food cold. I will have to update as time goes on and we have more use to see whether it was a good move or whether I should have gone for another absorption unit. As it is, I think the price ended up being comparable. I should not need to carry the FPSC cooler unless we have a need to have more capacity. However, with the increased usable space in this, I don't think it will be necessary very often.

As for the delta on energy cost, I have no idea how to calculate that. On DC power, there is absolutely no comparison. The 8501 would drain the old dual 6V battery setup in a matter of a few hours. My brief weekend with the CRX-1110 indicates that I could probably get at least 24 hours or more in hot weather. With the insulation I added after the weekend, and if the temperatures were cooler, it would likely be able to run for much longer. Of course, it will not run nearly as long as the 8501 would run on a full propane tank. The trade-off is that it will keep temperatures much cooler, even in hot weather.

It is also automatic changeover between AC and DC power so no more remembering to switch manually.