Many appliances in RV are designed to run on propane or multiple power sources. One would think that you would be able to run your Air Conditioners on propane as well. However, Air conditioner units in RVs are compressor refrigeration units that use a motor thus designed to run on 110 volts or 220 volts depending on the size of the RV. The compressor on the AC unit uses a motor that compresses the gas that causes the cooling, while another motor blows air through the fins that are cooled and circulates the cold air inside the coach of the RV.
To fully understand, why propane will not function as a fuel directly in operating an RV’s air conditioning we need to look at the types of cooling available and see which ones can use propane. Propane could be utilized as a fuel in a generator to produce A/C electricity to power the air conditioning unit. Advances in 12 volts and 24 volt direct current motors have also given rise to DC air conditioners that may someday replace the traditional Alternating power (A/C 110 volts) Air conditioner on your RV.
What Are The Methods Of Cooling? (Absorption & Compressor)
Absorption cooling is a chemical process, whereby ammonia is heated and cooled, which thereby produces cold. There is a plate that is heated at the bottom of a bunch of coils that pushes the ammonia up a tube and as the heated ammonia turns into vapor water separates and as it cools it becomes a liquid again and, in the process, cold is produced. The plate can be heated with 3 fuels; DC power, A/C power, and propane. Technically, this place could be heated with any kind of heat source such as natural gas, oil, etc. As long as you can get the ammonia to boil. This is how a typical RV fridge works, you can read more about it in this article on RV fridges.
The Compressor method of cooling is a mechanical process where the coolant is compressed by a motor that results in cooling. The compressor method of cooling is 5 to 7 times more effective at cooling than absorption cooling.
How To Run Your RV’s Air Conditioning With Propane (Or Generator)
An RV’s air conditioning does not directly use propane to run as does not operate as an absorption cooling. The only way to run your campers’ air conditioning with propane is to use an onboard generator or portable generator that uses propane to create the power to run your air conditioning unit.
The generator would need to be large enough to generate at least 2000 watts of continuous electricity, but a 3000 watt would be better able to handle the Air conditioner and other appliances in an RV. Air conditioners use a compressor to create cold air by compressing the refrigerant in the coils that are covered by fins. Another motor runs the fan that circulates the air in the cabin through the A/c unit. This is very similar to how your home refrigerator or compressor fridges work in RVs. You can read more about the types of fridges in RVs in this article.
If you are instant on running an RV’s AC on propane, then you need to convert the existing compressor cooling system in your camper from compressor cooling to absorption cooling. The mechanics of each type of cooling system is totally different. One is a mechanical chemical process and absorption is a heat and chemical process.
A change in a compressor to absorption would provide a loss of efficiency by 5 to 7-fold as cooling from absorption cooling systems are just not as effective. Then there is the size difference, which would mean the existing Air conditioning cover would not fit. With all this said, the cost-benefit to convert a compressor air conditioning system into an absorption AC system is just not worthwhile. The cost is better to spend on a better generator or invest in a different type of AC unit.
What Ways Can You Power Your RV’s Air Conditioner?
An RV’s air conditioner can be powered by 110 amp or 220 amp depending on the size of your camper. If your camper is large and uses a 50-amp plug, then it would be powered by 220 amp for the 2 air conditioners in the rig. However, if your camper is smaller then it would be powered with 110 amp. Since the typical RV air conditioner unit is 13,500 watts it can be run with a 15 amp home plug.
At the time of writing this Solar and lithium batteries are another way to run a camper’s air conditioning unit to keep cool. For many people having the volume of lithium batteries and solar panels to supply the necessary power is just not feasible. Though with advancements in Lithium batteries and solar panels the prices are dropping as are the density of the batteries and the efficiency of the solar panels increasing. The day will come shortly where it will be possible to run an RV’s A/c unit for the entire day. Not to mention advancements in direct current (DC) or 12 volts powered air conditioning units.
Do They Make DC Air Conditioners For RVs?
Advances in DC (Direct current) cooling compressors and DC motors have given way to DC air conditioners that run on 12 volts and 24 volts. This opens the possibilities for DC air conditioners that can run on solar power and lithium batteries for hours. There are several that are currently on the market. The current ones are better suited for class B motorhomes and camper vans. Dometic cooling added few additional models in the last year. I expect that there will be more on the market shortly. The highest appears to be 3000 watts, which is a far cry from the standard 13,500-watt typical RV air conditioner. Douglas also makes one that is 12v as well which appears to be 9800BTU on amazon.