What Size Generator Will Run A 5000 BTU Air Conditioner (What You Need to Know)

If you’re heading out in an RV, or looking for a place to set up camp, you’re going to want an air conditioner. An air conditioner adds a level of comfort to a trip that’s difficult to achieve elsewhere.

Even a humid swamp can feel like a tropical paradise with the right AC.

Unfortunately, the places where you’re most likely to need an air conditioner are also the places least likely to have a power grid. And an air conditioner without any power is no use to anyone.

What Size Generator Will Run A 5000 BTU Air Conditioner (What You Need to Know)

Instead, you need a reliable generator, which can power your AC and leave you refreshed.

For a 5000 BTU air conditioner, a 2000 watt generator is a decent size - but smaller might be possible. Read this guide to find the best size generator for your needs.

What Size Generator Will Run A 5000 BTU Air Conditioner?

Across the days of summer, there are sure to be occasions when you find yourself craving an air conditioner.

Whether you’re heading out on the road, or sheltering at home, an AC is an often longed for appliance. A 5000 BTU air conditioner is a compact unit that works effectively to cool small spaces.

A 2000 watt generator is the minimum needed to run a 5000 BTU air conditioner. This should be able to start the air conditioner, and keep it running. 

If you’ve done your research into air conditioners, this number might be large. A 5000 BTU air conditioner generally only needs 500-600 watts when running, meaning a 2000 watt generator is operating with a hefty surplus.

However, the running wattage is only part of the picture. When choosing the right size generator, the other important consideration is the starting wattage.

The starting wattage is the power needed when an appliance is switched on. For an air conditioner, a pretty big energy kick is needed to get the compressor going.

Because of this, the starting watt requirements can be double that of the running power. So, even a relatively small 5000 BTU air conditioner needs 1000 or 1200 watts to get going.  Well within the capacity of a 2000 watt generator.

It is often possible to run a 5000 BTU air conditioner with a 1000 watt generator. However, it limits the usage of the generator.

When choosing a generator to run your air conditioner, it’s easy to dismiss the starting watts and focus on how many watts are needed for operation. However, this means you’ll underestimate the size of the generator needed, and end up with something far too small.

Although these are the average power needs, make sure to check the specific starting and running watts for your air conditioner. An older unit, or one that isn’t energy efficient, may require a bigger generator.

EER - Energy Efficient Air Conditioners

If you’re hoping to buy a smaller generator, then you need an AC that doesn’t require as much power. In that case, you may want to look for an energy efficient air conditioner.

The energy efficiency ratio (EER) indicates how much power is needed in comparison with other units of a similar size. A 5000 BTU air conditioner with a good EER will need fewer watts to start, and to run.

An air conditioner with a 10 EER rating is fairly standard, and the higher the number, the better. Avoid air conditioners with a low number - these need a large amount of power to deliver poor results.

Why Use A 5000 BTU Air Conditioner?

5000 BTU is generally considered to be the smallest size air conditioner, but it still delivers a decent output. For travelling, that means it can effectively cool a small space, without using too much power.

Ideal if you’re trying to save energy, or reduce weight.

A 5000 BTU air conditioner can be used to cool a space that’s roughly 200 square feet - but it works best in smaller rooms.

For a tent or small RV, this should provide enough cool air to get you through those scorching afternoons in the dog days of summer. On really hot days, however, you may find it lacks oomph.

In your home, a 5000 BTU air conditioner is ideal for providing a cold escape on oppressive days. Let it chill a small room, and you have a blissful retreat against the raging sun. 

Don’t Forget About Everything Else!

Although many of us dream of a chance to escape into the wilderness, the reality is that creature comforts are hard to give up. When you’re camping, or travelling in an RV, it’s likely the air conditioner isn’t the only thing that needs power.

If you buy a generator solely to power your 5000 BTU air conditioner, then 1000 watts might be enough - especially if you use the AC on a low setting.

However, it might be worth paying for a larger generator, so you can use more appliances. Even a 2000 watt generator should allow you to plug in the coffee maker alongside the AC. 

Of course, a very well-prepared person could plan their day so only one thing needs the generator at a time. But few of us want to use this level of thought on a vacation. Instead, a larger generator allows for freedom of usage.

That said, you need to be careful not to overload the generator, regardless of the size. Stay aware of the starting watts needed for different appliances, and don’t push the generator to its limits.


A 1000 watt generator is often large enough to power a 5000 BTU air conditioner, but a 2000 watt generator provides more flexibility. When running, the air conditioner often needs a low amount of watts.

However, the starting watt requirement is much higher.

If you intend to use the generator to power more than just the air conditioner, a larger size is often better. For campers and travelers, the AC can be used alongside all the other appliances needed for a comfortable trip.

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.