This Old Campsite
This Old Campsite
Upgrading to a Residential Refrigerator
By Warren Petkovsek
Have you ever been somewhat less than satisfied with the absorption (gas/electric) refrigerator in your RV? Have you ever had one of those things go bad and had to deal with the cost of replacement? An absorption refrigerator is one of the most expensive appliances in any RV. Have you ever wished that the refrigerator in your rig worked as well as the one in your home? If you are like me, you've probably never given it a second thought. After all, you are camping which includes "roughing it" a bit. Even so, a residential refrigerator will start up and get cold quicker, make ice faster and keep things like ice cream frozen harder than the gas/electric refrigerators found in most RVs. Another advantage of a residential refrigerator is that without that large absorption (cooling) unit, there is much more interior space with an appliance that is the same outside dimensions as the gas/electric unit. The cost of purchasing a residential refrigerator may also be about half that of a gas/electric unit.
Lets talk a little more about how to do this conversion. There is one caveat. Please understand that this is not a "do it yourself" or "how to" step by step procedure. I've never actually done this myself, but I've talked to folks that have and I wouldn't have hesitated to do this simple job myself. That's not going to happen because our new 5th wheel came equipped with a big Samsung refrigerator powered by batteries and an inverter. 'Lucky me!
Let's talk about the conversion. A friend and coworker of mine bought our old Terry 24 foot travel trailer years ago. When the refrigerator finally quit on him he simply replaced it with a small dormitory style refrigerator. He just plugged it in and wished it well. It was much shorter than the unit it replaced so he just built a few shelves in his new found space. He didn't even install an inverter to run the appliance on battery power. This is because the only thing they ever did with the trailer was attend some NRA sanctioned cowboy style shooting events that were not very far away. He told me that the contents stayed cold enough during the short trip. This is what we are supposed to do with our propane powered refrigerators anyway. We ARE NOT supposed to have them running on propane as we travel down the highway because of the danger of a wreck and the potential ensuing fire.
There is, however, a way to keep a residential refrigerator running safely while we travel down the road or any other time that we are without 120 volt electricity such as dry camping. We simply install an inverter, sometimes called an inverter/converter. An inverter converts 12 volt DC electrical power to 120 volt AC household power, the same as if you were plugged in to "shore power". Since there is no propane or the associated pilot light of an absorption unit, the inverter is a safe way to travel with your refrigerator running. It is also good for dry camping when you don't have any shore power. I'll leave it up to you how you will keep your batteries charged while dry camping. We feel that having an inverter to keep your refrigerator running would be worth the cost because in our part of Texas we are prone to have hurricanes that cause us to evacuate. Naturally, we're bringing our 5th wheel with us because it may be the only home we have after the storm. It is not unusual to be tied up in traffic for sixteen hours or more during these evacuations so we feel that anyone making this conversion should spring for the inverter set up.
When you are traveling on the highway your tow vehicle will keep your batteries charged so that the inverter can run the refrigerator while you travel. Be careful because many vehicles do not have a large enough wire to carry the current necessary to keep your batteries charged. This is a fairly common problem and you need to have this system checked out to be sure that it is up to the job.
OK. Let's say that you have decided to replace your gas/electric refrigerator with a residential unit and have also decided to install an inverter (smart!). You will only need the inverter when you are traveling or dry camping. When plugged in to shore power you will be able to use that 120 volt power just like at home. This means that you will need a manual switch to go back and forth between the new inverter and the converter that you already have. 'No big deal.
There is another choice. An inverter/converter (sometimes called inverter/chargers) will include the inverter and a high tech battery charger in the same unit. These inverter/converters will also have an automatic transfer switch. When this switch detects another source of AC power such as campground shore power or a generator it will automatically bypass its inverter function and allow your refrigerator to run on shore power. It will also switch itself to "converter mode" and begin recharging your batteries. With the better inverter/converters the battery charging function is a "smart design" like the Battery Tenders and other high tech chargers that are available today. They will not allow the batteries to become overcharged. Instead they will provide a conditioning charge that will not harm your batteries.
How much power do you need? Most refrigerators will have the manufacturer's power rating on a label near where the AC cord is found on the back of the appliance. If this label expresses the power requirement in watts then you just buy an inverter with at least that capacity plus a little more (more on that later). If the label expresses the power requirement in amps then you need to use the formula, watts = volts x amps. Simply multiply the the amp rating of the refrigerator x 120 (volts AC) to find the power requirement of the refrigerator in watts. Your inverter should be a little bigger than that. Why? All appliances or machinery that have compressors, pumps or fans will have a significantly higher current requirement at start-up than during continuous running. Your refrigerator's compressor will cycle on and off in order to maintain the temperature set point. Every time the compressor comes on there will be a spike in the power demand and you need to be sure that you're inverter is rated high enough with a surge capacity big enough to handle that. Generally, you can't go wrong with a 2,000 watt pure sine wave inverter. I can plug into one of the outlets on the inverter/converter on our new 5th wheel and can run my 150 psi air compressor on batteries alone. 'Impressive.
Well, the hard, technical part is over and it's time to talk about which residential refrigerator to choose and how to install it. The main determining factor in your choice will be the outside dimensions of the new unit. Will it fit into the space you have after removing the old absorption unit? According to the three of my friends that have done this, it is actually easier than you might think. Two friends have added a little trim molding to cover the gaps and the third friend said the replacement refrigerator fit perfectly with no additional trim required. You will need to secure the appliance in place with whatever brackets or clamps will work for your application. You can go to a retail outlet like Sears, Home Depot or Lowe's and find a refrigerator with the dimensions that will work and with features that will meet your needs. One of these friends did this conversion just this year (2015) and, at the time of this writing, said the new refrigerator from Sears fits perfectly and cost $440.00. The replacement gas/electric unit from Camping World would have cost them over $1,100.00, would have been much smaller inside and would not have worked nearly as well.
The last thing to consider is how to keep the doors closed while you are traveling down the road. Residential refrigerators, naturally, will not have any kind of locks or straps for this purpose. 'You know what? I can probably just leave this up to you. Each RV and each set up will be a little different anyway. Since you will only need to keep the doors secure while traveling, it doesn't really matter what it looks like. All my friends that have done this have devised their own system of snap straps or bungee cords and they all work just fine.
Well, I hope I've given you some useful information as well as something to think about if you ever need to replace your RV's absorption refrigerator. If you are shopping for a new rig you might want to consider what I did and buy the residential refrigerator option that is widely available in the industry today.
All the best and happy trails to you!
Copyright 2015 by Warren Petkovsek