RV Air Conditioners fall into 2 categories and two sub-categories. There is usually a roof air conditioner that services the “house” portion of the RV (or in the case of a travel trailer, the whole trailer). These air conditioners can be ducted or non-ducted. Additionally, a motor home will be equipped with a dashboard (dash) air conditioner which will serve the driver and passenger.
Roof Air Conditioner (A/C)
Example of a Roof Top Air Conditioner
The A/C is most likely located on the roof and will add 8-12 inches in additional height to the profile of the RV. RV air conditioners are controlled either with switches for the fan speed and thermostat on the front side of the A/C unit or with a wall thermostat similar to the one on your home. The air conditioning will be either ducted or non-ducted. Ducted air is just like the air conditioning in your home and is controlled by a thermostat. Non-ducted air will come from a single ceiling mount fan/supply unit usually located in the center of the RV living area; also controlled by a wall thermostat or controls on the unit itself. We will discuss both systems below
Ducted Air Conditioning
Trailers and motor home air conditioning is often ducted; just like your home. The advantage to ducted A/C is that you have more control over the distribution of the air and the ability to regulate air flow to various areas in the RV. However, as mentioned above, in warm climates the ducted A/C will have to work harder to do the same job. Also, keep in mind that RV air conditioners will seldom be able to cool the interior much more than 20 degrees from the outside temperature.
Non-Ducted Air Conditioning
We prefer this set up for smaller trailers or RVs particularly if you will be driving in warmer weather. While it may seem counter intuitive to have the air coming from one source, having the air ducted throughout the RV makes the air closer to the roof and therefore closer to the sun. Which means that the air conditioner has to work harder to keep the RV cooler. However, if you are in milder climates or living in the RV then a ducted air conditioning system might be a better way to go.
Thermostats
The style of thermostat in your RV will depend on the manufacturer. They run the gamut of simple dials or levers to digital readouts. It is important that we note here one thin about cooling your RV. The A/C unit is only capable of cooling the interior temperature to about 20 degrees below the exterior temperature. The RV furnace is controlled by the same thermostat, but it is a different system.
Dash Air Conditioner
The auto or dash air conditioner in a motor home is the same as the one in your passenger car. It is not powerful enough to cool the entire RV. However, if it is just the two of you the dash air will be sufficient. If the weather is fair, then it might be enough for one or two passengers to be comfortable without using the generator.
Final Thoughts and Words of Caution About RV Air Conditioners
In conclusion, the best way to cool the entire RV is to turn on the generator followed by the roof top air conditioning. However if you want your A/C to last and operate correctly, please heed the following cautions:
- The dashboard air conditioning creates an additional burden on the RV engine which increases engine heat and reduces fuel economy.
- Avoid using the dash A/C when climbing hills or steep grades.
- Never start or stop the generator with the air conditioning in the ON position
- Never attach or detach the shoreline power cord to a live receptacle with the air conditioning in the ON position
- Under humid conditions, run the A/C fan on “high” to reduce the possibility of ice forming on the roof top condenser. If the temperature gets too cold in the unit, turn the thermostat down and leave the fan on high.
