Troubleshooting Roof Top RV Air conditioners RV rooftop air conditioners pack an amazing amount of cooling power into a unit that is lightweight, will run off 120 volt a.c.power, and will survive the rigors and vibrations of over the road travel. No matter which brand you have- Coleman, DuoTherm, Carrier AirV, Emerson Quiet Cool, or another- they all work on the same principal. To understand what can go wrong- let's first look at how they work, with some basic theory. Like a refrigerator, an air conditioner operates not really by cooling the air, but rather by removing the heat from it, and dumping the heat outside. While this may seem like "nit picking", it is a very important concept in the operation of the unit, and vital to understanding how it works. The basic parts of an air conditioner are the sealed system- consisting of a compressor, a condenser, an evaporator, and the tubing used to tie it all together, the air moving system, consisting of a motor (only one in a typical roof top unit), and two fan assemblies- one to move air across the condenser, the other to move air across the evaporator.

The sealed system contains the refrigerant, which in this case is R-22. We will start the heat removal process at the compressor- which, as the name suggests, compresses the refrigerant (which at this point is a vapor), at the same time adding heat to it. how much is 5 ton ac unitThis "superheated" vapor then travels to the condenser (the "outside coils"), at which point the heat that was added by the compressor is removed (by the air flow from the condenser fan), cooling the vapor and causing it to condense to a liquid. through the wall ac heat unitsFrom here the liquid travels through a capillary tube, which regulates and restricts the amount that can flow through it, into the evaporator (the "inside coils"). how ac split unit worksThe liquid refrigerant is then able to expand, but in order for it to expand, it has to absorb heat from the air being passed across it by the evaporator fan.

As the refrigerant reaches the end of the evaporator, it has absorbed enough heat to vaporize it, and it turns into a superheated vapor. From here the suction side of the compressor pulls this superheated vapor in, compresses it, and the cycle starts over again. Basic compressor based refrigerant cycle From this explanation we can see that there are only a few requirements for a properly operating air conditioner. A properly designed system (which is a given), A properly charged system (we'll get to that in a bit), and adequate airflow over the condenser and evaporator, so that the evaporator can absorb enough heat, and the condenser can "dump" the heat outside. A major part of the refrigeration process is the fact that it takes far more energy (heat) to change a substance from one state to the other- by state, I am talking about solid, liquid, or gas. When talking about air conditioners, we measure energy in the form of btu's. A BTU is the energy required to raise the temperature of one pound of water one degree farenheit- so to change one pound of 32° water to 33° water requires 1 btu, but..

to change one pound of 32° ice to one pound of 32° water requires 144 btu's. The same principal holds true with the refrigerant in air conditioners- the heat is absorbed in the process of changing the refrigerant from a liquid to a gas. If the unit is not properly charged, the change will take place too quickly, or not at all. But... the reason that I point this out is not to have people run out and have their service man "Check the Freon ®"- for two reasons- One- the system is sealed with the proper charge from the factory, and the proper charge is usually around 13 ounces of r-22. With this small amount of refrigerant, if there is a leak in the system, odds are that it will be empty, and not just "low". The other reason is that it takes a lot of care and a scale to weigh the refrigerant to properly charge one of these units. I'm not saying that it cannot be done with simple gauges, but the likelihood of getting a proper charge is very low- and 95% of the time, the refrigerant charge is fine.

All right all ready- how do I fix it..How to Recharge an RV Air Conditioner In order for the air conditioner in an RV to operate effectively, it must be recharged when necessary. According to the HubPages website, the air conditioner in an RV uses refrigerant to cool the air as it passes over the evaporating coil. The refrigerant maximizes the efficiency of the entire air conditioner. If the refrigerant is low it can be refilled to the necessary level. However, if the refrigerant runs out completely then the air conditioner will have to be recharged. Lower the power that is supplied to the air conditioner before beginning to work on the unit. website explains that this can be done by accessing the electrical breaker in the panel box. The power must be lowered in order to work on the air conditioner safely. Determine the specific kind of refrigerant that should be purchased in order to recharge the RV air conditioner. The specifications should be listed on the side of the RV air-conditioning unit.

Remove the lid of the RV air-conditioning unit. website specifies that the shroud screws around the lid should be removed using a socket. Lift the lid straight up in order to guard against damaging the coils inside the unit. Use a refrigerant gauge to check the level of the refrigerant. Adding more refrigerant will recharge the air conditioning unit. In order to add refrigerant, unscrew the port with a wrench. Slowly add the refrigerant to the air-conditioning unit. As the refrigerant is added, the temperature differential between the air within the unit and the air in the RV should be monitored and recorded numerous times. When enough refrigerant has been added, the temperature differential between the air-conditioning unit and the RV temperature should vary by about 20 degrees Fahrenheit. Restore the power to the air-conditioning unit and monitor the temperature in order to ensure that the air conditioner has been charged effectively. Make sure that the lid to the air conditioner unit is securely in place so that the system stays protected and clean.