Motorized and towable recreational vehicles generally have at least one air conditioning system, and sometimes two or three, mounted to the roof. Wall thermostats can be analog or digital. Set the mode button to cool and use the up and down arrows to set preferred temperatures. High outdoor humidity means more moisture in the air, requiring the a/c system to work harder. Run the a/c system on high fan speed during high humidity.

A/C systems require a supply of electrical power from shore power or the generator. When using shore power, test the voltage at the power pedestal with a voltmeter. Use of an extension cord may reduce the shore power supply. Avoid overloading the electrical supply. Engage multiple air conditioning systems in sequence. Reduce a/c usage while operating additional on board appliances. Use the dash a/c to cool the cockpit during drive time.

Inside ceiling vents include removable filters that can quickly clog with contaminates in the air, dust from road travel and pet hair. An easy way to maintain the a/c system is to frequently washing these filters with a mild soap and warm water solution. Rinse the filters with clear water and allow them to air dry before reinstalling. Do not run the a/c system until all filters are back in place.

If the system fails to operate, check the breakers located in the bedroom 120 Volt AC panel. It is not necessary to recharge the roof a/c system. If the unit loses charge, replacement may be necessary.

The roof mounting should be regularly inspected. This includes removing the shrouds, both front and rear, and clearing away insect and animal nests in the fan blades that are restricting air flow. The water drain holes should also be examined and cleared of blockage. Fasteners installed to a one-inch foam seal inside the a/c vent can loosen from road vibration and should be routinely inspected and tightened to one-half inch. Avoid over tightening.

Coils in the a/c system should be cleaned at least once time each year. Clean the coils more often when traveling in dusty terrain. Coils can be cleaned using water or compressed air.

Inspect the roof a/c shroud for signs of cracking. Use a Phillips screwdriver to tighten the four screws that attach the shroud to the roof surface. Replace rusty or stripped screws. These four screws used to secure the a/c shroud must be attached to keep the head flush. If a screw is installed at an angle, road vibration may cause the shroud to crack over time.

Help the a/c system work more efficiently by keeping the entry door and windows closed. Extend awnings to reduce sun glare into the RV. Minimize the use of overhead lights and heat generating appliances. Test the a/c system prior to departure. Service the a/c system during the winter months.