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If you are a happy owner of a big camper that needs a 15,000 BTU air conditioner to cool it off, you might be wondering if a 3500W portable generator will have enough power to run it smoothly.
A 15K AC is a large unit for long motorhomes or big rooms of 800-900 square feet. No matter if you’re using this AC for a travel trailer or for your house, you’re gonna need to make sure that it will run without interruptions caused by the power outage.
When this happens, it is always a good idea to have an appropriate generator on hand to keep an aircon operational. Not to mention that you will have no other choice but to use a portable power generator for an AC in your recreational vehicle.
Of course, this can pose a problem for those who are unsure whether their generator has sufficient power to keep the AC unit running smoothly and consistently. For example, finding a generator for 15K BTU models might require research to find the one that will keep things operating optimally for as long as necessary. In the following sections, we will take a look at the things to keep in mind when shopping for a 3500-watt generator for RV AC or any other unit with 15,000 BTU.
How Big of a Generator Do I Need to Run a 15,000 BTU Air Conditioner?
To begin with the basics, it is crucial for any RV traveler or those who want to be prepared for a power outage, to understand how many starting Watts 15,000 BTU AC requires. Fortunately, there are a few basic rules that will help anyone correlate the size of an AC unit with the output needed from a generator.
At a bare minimum, you’re going to need a generator that can output at least twice as many Watts that an AC consumes while running. For this reason, it is important to find a generator with plenty of starting power. In most cases, you would need some extra Watts if you’re using a big AC like 15,000 or more.
More specifically, on average, the 15,000 BTU AC requires 1500W in order to operate. With that in mind, the starting Watts for this size of an AC is 3500.
Finding a generator for 15K BTU air conditioners will depend on the characteristics of the specific model, but it is pretty safe to say that a 3500-watt generator is a minimum that is required to start and power an AC running at 15,000 BTU. Keep in mind, that experts recommend a 3600W generator for this aircon size.
Before you buy a specific portable generator, refer to your AC’s manual and ensure that the generator’s starting Watts are equal to or higher than that required by an AC.
Will a 3200-Watt Generator Run a 15,000 BTU Air Conditioner?
For those who have a slightly lower output on their generator, there might be some problems when it comes to cranking up and running a 15,000 BTU AC unit.
While 3200 watts is more than enough to keep the unit operating once it gets started, it will not be enough to give it its initial jolt of starting energy.
Long story short, you will need at least a 3500-watt generator for RV AC units with a 15,000 BTU output. Having said that, a 3600W generator is preferable.
In case you already have a 3200-watt generator but haven’t purchased an AC yet, you may want to consider a smaller aircon of 13,500 BTU. Since this AC only requires 2750 starting Watts, using it with a 3200W generator will work just fine. Given that the area that you’re planning to cool off is between 500 and 700 square feet.
How Many Amps Does a 15,000 BTU Air Conditioner Use?
One final detail to consider before using an AC unit with a generator is how many amps the particular device will use when in operation.
For a 15,000 BTU AC unit, the simple answer is that it will require from 10.87 to 16.30 Amps. On average, expect something around 13 Amps.
There are some other factors that can lead to a slightly different result, however. For instance, the type of air conditioner has nearly as much impact on the amps being consumed as its size.
Since a unit created for use in a recreational vehicle will use more electricity than a comparably sized unit made for window installation in a home, this is an important piece of the puzzle when finding a 3500-watt generator for RV AC.
As long as a 3500W portable generator can provide around 15.9 Amps of power (with 220V), you should be good to use it with a 15,000 BTU aircon in both your home and your RV. Especially, since the RV AC runs on 120v which makes the output Amps produced by a 3500W generator equal to 29.17 Amps (Amps = Watts/Volts).
There is an even more precise formula that allows you to calculate how many Amps your RV AC requires. It is based on EER (Energy Efficiency Rating) that should be available from your AC’s owner’s manual. Just divide the BTU by the EER and then divide the result by the voltage of your AC. For example, for the 15,000 AC with an EER of 10, it would be 15,000 / 10 / 120 = 12.5.
In most cases, the amperage will be stated in your AC’s owner’s manual, along with other specifications like the voltage, wattage, and number of BTUs.
