Often, having to level an RV for proper refrigerator operation is mentioned. But is this still necessary in 2024?
Well, it depends.
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RV Refrigeration
Keeping food cool is essential for food preservation, allowing RVers to have fresh foods for the trip. Without refrigeration, we’d have to depend on other methods of preserving and reconstituting food, including canned, freeze-dried, pickled, salted, or jarred foods. While many folks camp this way, I think most folks appreciate the convenience of refrigeration over coolers and ice boxes.
For most of the history of RVing, absorption refrigerators were the best and only option. The first type of commercial refrigeration, absorption refrigerators, uses an ammonia-based refrigerant to absorb the heat from inside the box and expel it to the outside. Of course, this is how most cooling systems we are familiar with operate, but no compressor is needed with this system. Instead, heat is used to boil the mixture, which basically vaporizes, flows through a cooling unit, and absorbs the heat as it expands in the cooling system, changing from a gas back to a liquid.
This system, while functional, has its downsides. First, the system’s efficiency depends on the ambient temperature and the ability of air to flow across the rear coils efficiently. Failure of this airflow causes the cooling to become labored or fail. If, in a hot climate, the air entering the coils at the bottom is too hot, the unit will not cool effectively. People have noted that having the refrigerator side of the RV parked in a hot summer sun creates more issues with the refrigerator. Also, airflow can be hampered if the refrigerator cabinet and baffles are not appropriately designed or installed.
The refrigerator must remain comfortably level or within three degrees of level. The reason is the refrigerant must flow through the cooling unit using heat and physics. There is no pump or compressor involved. If used off-level, the boiler can overheat, resulting in the sodium chromate (rust inhibitor) in the coolant precipitating out as flakes, which can plug the cooling unit. Once plugged, the cooling unit is junk and must be replaced.
Lastly, and frankly, is the fire issue. RV refrigerators were regularly recalled for several years because of leaks that led to fires. I performed hundreds of these recalls across the northeast US and have seen the results of refrigerator fires many times. The newer designs and recall kits have made the problem less of an issue. However, the cost of replacing these refrigerators can be high. The large 4-door refrigerators could cost upwards of $5,000 to replace.
Some years ago, manufacturers started offering residential refrigerators in motorhomes with power sources to support them on the road. Most motorhomes have generators and inverters that can run the fridge if there is a fuel supply or power source.
As time has progressed, new technologies are replacing absorption refrigeration in RVs. The companies that build them have reduced their model lines to select models.
The New Kids on the Block
Compressor-driven refrigeration has all but replaced absorption refrigerators in RV use because of solar and lithium batteries and inverters.
Compressor-driven refrigerators in RVs are in three basic formats: Residential units, AC compressor models with a built-in AC inverter that allows the unit to run from the 12 Volt DC system, and true 12 Volt DC compressors.
The residential units depend on batteries, inverters, and an outside charging source to keep them running off the grid. This includes solar and charging from the engine alternator while on the road.
The other two formats also require a robust 12 Volt DC system to operate off the grid, but with modern solar, lithium, and inverter systems, this can be accomplished for longer term off grid adventuring.
The key term with these refrigerators is “compressor.” In other words, the motor in the compressor moves the refrigerant from the condenser to the evaporator side. This means that level is much less important for these models than absorption.
To Level or Not to Level?
That said, keeping an RV level is about more than refrigeration. The water system is designed to operate in a level environment. Slideouts should only be used when the RV is level to prevent problems. Of course, comfort is also a consideration. I, for one, can’t sleep with my head down!
To be clear, you may not cause any damage to your RV using it in an un-level condition, provided you don’t have an absorption refrigerator. That Love’s or Flying J parking lot is no longer a problem. Just understand what limitations you might have.
What’s the Best Refrigerator Technology? Should I change what I have?
Well, again, it depends. Compressor technology is much better than absorption, period. There is no question that absorption is on the way out.
But you have to have the energy infrastructure to support it.
Fifth-wheels, for instance, frequently come with double-size battery boxes to accept two batteries. This is to support the inverter and the refrigerator, at a minimum, while the unit is in transit. But, without solar or genset charging, the time spent off the grid will be limited.
Many RVs are equipped with solar and lithium-based 12 Volt systems from the factory. This means the unit is ready for off-grid fun out of the box and can be expanded if needed.
You have some decisions to make if you have an older unit that needs a replacement refrigerator.
The large side-by-side and four-door models of absorption fridges have been discontinued. Some parts are available in the aftermarket, and some companies claim to be able to rebuild failed RV cooling units. If the problem is electronic, the availability of parts may be an issue in the future. Most of the manufacturers’ spare parts were sold at auction, so they are out there. Tim’s RV in Erving, MA, for instance, bought a truckload of them (along with truckloads of other parts from Norcold and Dometic), as have other RV surplus warehouses.
For my two cents, if I had a failed absorption fridge, I’d be inclined to replace it with a compressor-driven model and fill in the vents in the fridge compartment. I have lithium and solar on both my fiver and truck camper, and I could survive off-grid for a while with both. The question comes down to a cost-benefit analysis. The truck camper has a newer Norcold Polar 7 3-way model, and with everything considered, I wouldn’t change that one. The four-door absorption fridge I have in the Montana is another matter. However, it would likely require the removal of the galley slide to replace that unit, which complicates the decision. Time will tell. Since that unit is no longer available, my hand may be forced.
As mentioned, don’t forget RV surplus warehouses and stores for service parts and replacements. Sadly, some dealers and service centers look no further than a distributor’s catalog for parts; when the parts aren’t there, they give up. The good parts people know to let their fingers do the walking Googling. 😉
The RV PHD Newsletter is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.
