Economy Refrigerator

I've never been a fan of ammonia absorption refrigerators found on most RVs. I've found them to be quite variable on how well they cool, some times freezing the food, other times barely able to get below 50 degrees - all at the same temperature setting.  You have to keep your RV parked relatively level for them to work at all. Their one asset, the ability to run on propane, is also a major hassle when traveling. I'm a firm believer in following the safety rules, which include turning off your propane at the tank when driving. This means your refrigerator must run on 12 volts while driving, and these fridges don't seem to work well on 12 volts. Also when you stop somewhere, you have to determine if you'll be gone long enough to make it worthwhile to turn the gas back on and re-light your refrigerator, versus draining your battery on 12 volts.
 
Lately, our refrigerator had stopped working on its 110 volt AC mode. I had plans to pull it out so I could fix it. After reading about someone else who had replaced their RV fridge with a standard 110 volt economy "dorm" refrigerator, I decided it would be fun to try a similar experiment, especially since I'd just installed an inverter and now had 110 volt power wherever I went.  I realize that these regular cheapy refrigerators are not made to take the abuse of road travel, but I considered this a learning experience and experiment. So I went out and bought a Haier HSB03  2.7 cu. ft. refrigerator from Walmart for $90 so I could play.

Empty refrigerator cabinet after removing the Dometic absorptive refrigerator.  Since the new refrigerator is for indoor use only and does not need outside ventilation, I covered all the ventilation openings with thin foam (held by duct tape). Although not yet done in this photo, I did the same thing with the vent openings in the access panel seen toward the bottom. This keeps the elements, temperature extremes, and insects out of the van.

I capped off the end of the gas line that had supplied the prior refrigerator. A soap test confirmed a gas-tight seal.

Bottom of the fridge with my brackets attached. The cabinet opening was about 2 inches wider than the refrigerator. I used L-brackets and drilled holes in them so they would line up with existing screws on the refrigerator bottom and extend out from the side by exactly one inch.

The front L-bracket on the hinge side of the door went under the existing door bracket. I used washers on the door and other screw so that everything would stay even.

Washers in place, giving the same thickness as my L-bracket.

Finished installation. It was a little difficult screwing in the L-brackets to the side walls of the enclosure, but doable with the correct tools and hex head screws.  The refrigerator just plugs into the 110 volt outlet used by the prior refrigerator.

I also bought a pin to put in an existing hole at the top of the door. A short cord ties this pin tightly to a small eye bolt screwed into the side wall. This holds the fridge door shut while we travel, yet the pin pulls out easily to open the door when needed.

Results so far:
 
I first did a battery drain test to see how long I could run the fridge off the inverter without charging the batteries. In 24 hours, the refrigerator drained the batteries about 30% to 40% (based on voltage measurements).  I have two 92 amp hour AGM batteries. I figure I used about 70 amp hours in these 24 hours. This correlates well with current draw, which was about 7 to 8 amps when the compressor was running. The compressor ran about 30 to 40% of the time.  Daytime temperatures in the van were about 86 to 90 degrees. Night-time low was 69. The refrigerator keep a temperature of 39 to 41 degrees based on the electronic refrigerator monitor we always use. By the way, I started this test when I first turned the fridge on and its inside temp was 84 degrees.  It took about one hour to cool the fridge down from 84 degrees to 50 degrees.   Since I doubt i will ever go more than 24 hours without driving the Roadtrek or having shore power, this 110 volt refrigerator concept works well for me from a power requirement point of view.
 
Next we tested the refrigerator on a three day camping trip with about 200 miles of driving. I was not sure if the refrigerator would stand up to the vibrations of driving, so we brought a backup cooler just in case.  The refrigerator worked beautifully throughout the trip, maintaining a temperature between 39 and 41 degrees. The tiny freezer compartment was able to freeze ice cubes.  The van alternator provides more than enough power to run the refrigerator and keep the batteries charged. When we got home, the batteries were fully charged.  The refrigerator is very quiet, although you can hear some faint gurgling noise when the compressor runs and the coolant is running through the lines. Overall, it's a little quieter than our home refrigerator and noise was never an issue at night when we were sleeping.
 
Conclusion:
 
I'm still not sure how long this refrigerator will last with the road vibrations.  I'm definitely sold on the concept of a standard compressor refrigerator instead of the inefficient ammonia absorption types.  If this Haier breaks relatively soon, I will probably replace it with a 12 volt compressor refrigerator specifically designed for RVs and boats. These are twice as efficient (typically draw 3 to 4 amps) and are designed to take the bumps. They can be pricey however.  If I can get a season or two out of this refrigerator, I think I'll just replace it with another cheapy model when the time comes.  Too bad they didn't offer a 12 volt compressor refrigerator as an option when we bought the Roadtrek.

Update 2012:

Just completed a 6000 mile trip out to California. The refrigerator is still working nicely. The van engine keeps the batteries charged easily every day while driving. There's enough battery capacity to run the fridge overnight. We have run into a few instances where we have had to run the generator for an hour or so to recharge the batteries when we dry camp for over a day without any driving. This is a rare occurrence for us. I am so glad I converted to a regular refrigerator! It operates much much better than the original ammonia fridge and we rarely need to turn on our propane tank now.