On a sweltering summer night, an RV can become an oppressive environment. A place that you normally associate with freedom and open roads transforms into an inescapable, humid box.
On those nights, you need an air conditioner.
A 15,000 BTU air conditioner provides enough cold air to chill even the dog days of summer. However, they need a lot of power to run. A generator is necessary to ensure you stay cool, but it also needs to be reliable.
To help you find the right generator for your air conditioner, we’ve put together a guide to some of the best on the market. There’s also a buyer’s guide, so you can narrow down what features are necessary.
Choose right, and you never have to curse a summer’s night again.
OUR TOP PICK
A generator from Champion Power Equipment comes with almost a guarantee of quality.
They’re one of the most trusted names on the market, consistently manufacturing top quality generators with innovative designs.
What makes this generator stand out is the amount of power it delivers for a bargain price. It has the capacity to deliver 4750 starter watts, and 3800 running watts.
More than enough to power a 15,000 BTU air conditioner, and several other appliances alongside.
When powered by gas, the generator has a fantastic 14-hour runtime (10.5 hours on propane). Multiple outlets allow this to be a truly versatile generator.
Powerful generators can be bulky, but there’s no convenience sacrifice here. The foldaway handle makes it easy to store, and never flat tires ensure smooth movement.
Cold start technology means this generator is up and running no matter the season.
The biggest downside is the noise. This model will be louder than an inverter generator, which can be disturbing.
However, it should still be quiet enough that there should be no hassle from the neighbors.
A blend of convenience and power, this is a great option for anyone needing a generator for a large RV.
During hot summer days, the AC can run full blast, without needing to switch everything else off.
Pros
- Dual fuel - Can run off both propane and gasoline.
- Volt Guard - A built-in surge protector keeps you and your appliances safe.
- 1 x 120V 30 A RV outlet, 1 x 120V 30A locking outlet, 2 x 120V 20A household outlets - Multiple outlets, for versatile uses.
Cons
- Noise - Can be disturbing when running.
EDITORS CHOICE
Another powerful option, the Westinghouse iGen 4500 is a gas-powered generator that can provide 4500 starting watts.
Clearly made with quality, this slightly higher priced option has several features that makes it stand out.
With the Westinghouse, what you get is convenience. The telescope handle makes it easy to move around, and the reduced weight is perfect for camping and travelling.
It can be smoothly wheeled, but picking it up isn’t too difficult either. There are few generators that have this much power at such a low weight.
A remote control start adds to the convenience as well, and is backed up by an electric start and a recoil start.
An LED screen finishes the whole thing off - the rotating display shows important information in a manner that’s easy to read, even in low light.
Where this generator really shines, however, is the noise level.
Even at maximum capacity, the Westinghouse is quiet enough that you’d hardly believe it was on. The low noise level is contrasted by the high fuel efficiency - it can run for up to 18 hours on a 3.4 gallon gas tank.
The Westinghouse offers the opportunity to sit back and relax.
Combining high power, high fuel efficiency, convenience, and low noise, you can plug your air conditioner in, and think of nothing but the cool breeze.
Pros
- 52 dBA Noise Output - Quiet enough to keep you, and your neighbors, happy.
- Easy to handle - A telescope handle, smooth wheels, and low weight makes this a portable generator.
- LED Data Center - Rotating display shows helpful information about fuel levels etc. even with little light.
Cons
- Choke issues - Some users find the auto choke doesn’t work, has to be manually disengaged.
BEST VALUE
The initial appearance of the WEN shows it to be a sleek and portable generator, which will fit easily into an RV.
The black and orange outer casing is distinctive and durable, and a lower weight makes it ideal for travel.
With 3800 surge watts and 3400 running watts, there’s enough power in this generator for a 15,000 BTU air conditioner.
However, if you want to run other devices alongside, it’s recommended to start the AC on its own, before adding appliances.
A decent run time is improved by an eco-mode switch, which increases fuel economy.
The design of the WEN is what makes it immediately striking. The display panel is well organized and easy to use, so you can quickly get to grips with working modes.
A digital meter monitors fuel consumption (among other things), and the display is very easy to read.
It’s only a shame that there’s no remote control start, which would have made the WEN generator even more convenient.
One issue with generators for air conditioners is that they’re likely to go through several months of not being used.
This can lead to blockages, which cause big problems when the next hot day rolls around.
WEN have navigated this with the fuel shut off system. Fuel is drained from the carburetor before shutting down, preventing blockages and limiting maintenance.
Pros
- Fuel shut off system - Drains fuel before shutting down, extending the generator's lifespan.
- 3-prong receptacles, USB port, and more - Multiple outlets, allows for a versatility of use.
- 57 dB at quarter load - Not silent, but quieter than the average generator.
Cons
- No remote control - Only one starting method.
RUNNER UP
This is the most powerful generator we recommend, delivering an incredible 12,000 starting watts and 9,500 running watts.
That means there’s more than enough to power a 15,000 BTU air conditioner, and plenty more as well.
The reason for recommending such a large generator is that it can handle almost anything.
Although a 15,000 BTU air conditioner won’t need such impressive wattage, smaller generators often mean nothing else can be used when the AC is on.
In an RV, this can be incredibly frustrating. With a 12,000 watt generator, there’s never any need to compromise.
Despite the awesome power, the DuroMax comes with an affordable price tag. It isn’t a budget option, but for what you get it’s very reasonably priced.
The main selling point for the DuroMax is the power, which means it is lacking on other fronts. It can get noisy, and you probably wouldn’t want to be running it at night.
There’s no clean power, so it isn’t suitable for charging smart devices. And it’s also heavy - at 224 pounds, this isn’t easy to carry around.
However, multiple outlets and a dual fuel design make this a surprisingly useful generator. If you want to power an air conditioner at home, then the DuroMax is more than capable.
It also provides a convenient back-up system in case of power outages.
Pros
- 12,000 starting watts - Incredibly powerful, able to run an air conditioner and plenty more.
- Dual fuel - Able to run on propane and gas.
- 50A, 30A, and 20A outlets - Multiple outlets make it a versatile generator.
Cons
- 224 pounds - This machine is known as the “beast”, and it certainly feels that way. The wheels sometimes struggle with the weight.
RUNNER UP
This generator from Champion Power Equipment is popular with RV users for many reasons.
The compact design and lighter weight is easily portable, the dual fuel design makes it easy to power, and the 3400 starting watts is enough for a 15,000 BTU air conditioner.
Champion Power Equipment is an incredibly well respected brand, thanks to years of delivering fantastic products. This portable inverter generator stands out because of the quality of the design.
It looks good, it does what it should, and it’s easy to operate. Straight from the box, you can have this set up in almost no time at all.
In terms of power, the generator delivers enough without any excess. If you want to use it with an air conditioner, it’s recommended to turn the AC on before plugging anything else in.
The noise level is low, at only 59 dBA. Neighbors on a campsite will find little to complain about when this is running.
With a Quick Touch panel, operation of the Champion generator is easy. There are multiple outlets, including a dual USB adaptor.
Clean power means this generator can be used to charge smart devices.
A 3-year limited warranty and Champions trusted customer support makes this generator a fantastic choice for an air conditioner.
Pros
- Dual fuel - Able to use both propane and gasoline.
- Quick touch panel - An easy to navigate design with an intuitive display.
- Parallel ready -Can be connected to other Champion generators, for an extra power boost.
Cons
- Difficult oil changes.
Best Generators For 15,000 BTU Air Conditioner Buying Guide
When you’ve never bought a generator before, it’s tempting to just buy the largest one in your price range. After all, a 15,000 BTU air conditioner is a big appliance. However, there’s more to consider when buying a generator than just power output.
Capacity
If you’re buying a generator specifically to power an air conditioner, it needs to have the capacity to match. For a 15,000 BTU air conditioner, you’ll need a generator with a capacity of over 3,400 watts.
When considering capacity, the two important factors are starting watts and running watts.
The starting requirement for a 15,000 BTU air conditioner is roughly 3500 watts. The running wattage is around 1500. The generator needs a capacity that matches both those numbers.
However, you may want to consider a larger generator. This would allow the user to power several appliances at once.
Noise
A generator can be a noisy machine, and a completely silent generator is still only a dream.
On a campsite, you have to consider how the noise will be affecting you, and how much it will bother the neighbors. For that reason, it’s better to buy a quieter generator.
A decibel level of 60 or under is considered to be a quiet generator. This is around the level of a normal conversation. The lower the number, the quieter the machine.
Some generators come with quiet technology, which is designed to reduce the noise output.
Portability
Spending time on an RV naturally requires a lot of movement. No one wants to have to struggle with a heavy and cumbersome generator every time you want to move to another campsite.
Handles and wheels are pretty much standard on a generator of this size, and they really are a necessity. A handle that folds away is particularly useful. Compact designs are easier to store when there’s limited space.
Consider the weight as well, because it might put a strain on the vehicle. Although most generators shouldn’t cause an issue, particularly large ones can really pile on the pounds. Below 100 pounds is considered to be a lighter generator.
If you only plan on running your air conditioner at home, then portability is less important. It’s still worth considering, however, or you’ll regret it when there’s a power outage.
Fuel Type
Generators typically run on either diesel, gasoline, or propane. Gasoline and propane are the more popular choices, as diesel is expensive. Gasoline gives more energy, and is easy to find.
Although some prefer propane, it’s much more difficult to buy on the road.
Some generators are “dual fuel”. That means they can run on either gasoline or propane. These are a fantastic choice, as you aren’t limited in what you use, and it’s easier to stock up.
Run Time
8 hours or more is considered to be a decent run time for a generator. This will last you through most of the night, and there won’t be a sudden shock when everything stops in the early hours of the morning.
The run time varies depending on the size of the fuel tank, but it’s also dependent on the load. A generator running several appliances at once will lose power before the same generator working at half capacity.
Look for the fuel efficiency level of the generator, as this can give a decent indication of potential run times.
Inverter Or Conventional Generator
Whether you buy an inverter or conventional generator will likely depend on which features you value most. An inverter generator produces cleaner power, which can be used to charge devices such as smartphones and tablets. Inverter generators are also quieter, and more fuel efficient.
However, they come with a larger price tag.
The conventional generator is louder and less fuel efficient, but you can get a higher capacity for a lower price. If you value more power for less money, a conventional generator is best.
Features
Convenience is an important factor in a generator, and extra features can really increase the ease of use.
Typical additional features include a remote control, a fuel meter, a low fuel shut off, and a USB port. These increase the versatility of the generator, and make life that bit easier.
If you want a generator for multiple uses, be aware of the outlets available. Some generators can accommodate a range of sockets, while budget choices might be limited.
Budget
Generators are expensive, although the price is most closely linked to the capacity it can provide.
If you want to save money, a lower capacity generator is better. However, cheaper generators can have poor run times, and are often noisy.
Frequently Asked Questions
What Size Generator Do I Need To Run A 15,000 BTU Air Conditioner?
To run a 15,000 BTU air conditioner, a 3400 watt generator is the minimum requirement. A 15,000 BTU air conditioner typically needs a starting wattage of around 3500, and a running wattage of 1500.
The generator needs to have the capacity to provide both the initial power surge, and the lower running wattage.
What’s The Difference Between Starting Watts And Running Watts?
Starting watts refers to the number of watts needed during the initial power up.
This is generally significantly higher than the running watts. Running watts refers to the power needed during continuous usage. This number is often much less.
For an air conditioner, the starting watts can be as much as double the running watt requirement.
Starting watts are sometimes referred to as “surge watts”, or “peak watts”. Running watts are also called “continuous watts”.
What Is A CARB Compliant Generator?
CARB refers to the California Air Resource Board. CARB requirements refer to how long a generator can run before it exceeds the emission limit. If you intend to use or buy a generator in California, it needs to be CARB compliant.
Jeremiah Pike
I'm an environment and energy blogger who teaches outdoor and energy enthusiasts how to be better informed when it comes to purchasing or maintaining a generator, solar panel system, or anything else related to your energy needs.