How to Power an RV Air Conditioner with a Generator

Having the power you need, when you need it is easy when you learn how to choose the right size generator for your RV. We break down the important considerations in your selection so you can enjoy smooth operation.

RV Generator Sizing: Surge Wattage

Tackling a project as complex as a self-contained RV power system demands precise calculations. When powering an air conditioner, the metric that dictates success or failure is the surge wattage (or starting wattage).

This surge requirement is always significantly higher than the running wattage. For example, a 15,000 BTU air conditioner may only require 2,000 watts to run constantly, but it could demand as much as 3,000 watts to start the motor. If your generator cannot provide that higher surge number, your AC will never kick on.

To ensure reliable performance, your generator must be sized to cover the A/C’s peak surge wattage plus the combined running wattage of every other appliance (microwave, lights, fridge, etc.) you intend to operate at the same moment.

Powering Two RV Air Conditioners

A major complexity in RV power systems is running multiple units. As a rule of thumb, while a single AC can be powered by a smaller kilowatt set, coaches running two rooftop air conditioners require a generator of 5500 kilowatts or larger to accommodate the high combined surge requirements and all other necessary loads in the coach.

Built-in vs Portable RV Generators

With a wide range of top brands available, choosing the right generator type is key to maximizing convenience and performance.

Built-in RV Generators (Permanent Mount)

Built-in RV generators are the preferred choice for powering an RV air conditioner, especially for larger, more complex projects.

• Higher Wattage Range: Built-in units offer a greater power capacity, making it easier to meet the high surge wattage requirements of air conditioners.
• Convenience: Once installed in the RV’s compartment, they require no manual setup and connect directly to the vehicle’s main fuel tank. Your power is available instantly, running automatically like at home.
• Noise Advantage: These generators are specifically engineered for quiet operation, often meeting the strict decibel limits enforced at many campgrounds.

Portable Generators (Open Frame & Inverter)

For smaller travel trailers, pop-up campers, or basic power needs, a portable unit may be a viable option.

• Cost and Flexibility: Portables are generally less expensive and can be moved and used outside the RV.
• The Inverter Advantage: If you choose a portable, we recommend a quiet inverter generator. Inverter models are significantly quieter than traditional open-frame units. Furthermore, you can parallel two inverter generators together to effectively double your power output and meet higher AC surge demands.
• The Trade-off: Be aware that portable units are heavy, require manual setup, and necessitate manual refueling—often an inconvenient task in the middle of the night.

Ferguson Home is the partner who can assist you at every stage of the process. By blending professional expertise with the right selection, we ensure you have the clean, reliable power and comfort you need for any journey.