How Big of a Generator Do I Need to Run a 5,000 BTU Air Conditioner?

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Updated September 10, 2022

If you are new to the world of indoor cooling, you may wonder, “How big of a generator do I need to run a 5,000 BTU air conditioner?” The best air conditioners, after all, require energy to run, and if you don’t have access to a standard electrical grid, you’ll need a generator. So what is the best size of generator to choose for this type of AC unit, and what are other options to increase efficiency? Keep reading to find out.


  • If you don’t have access to an electrical grid for power output, you’ll need an external generator to power an AC unit.
  • 5,000 BTU air conditioners do not have massive energy demands, so a medium-size 3,000-watt generator is more than capable, though portable generators may struggle and cause power outages.
  • To increase energy efficiency with an AC, change the filters regularly and only run the unit when needed.

Generator for a 5,000 BTU AC Unit

Living off the electrical grid is not easy if you wonder what size air conditioner is needed for a 14×70 mobile home. However, once you decide what size central air conditioner to get or what size window unit you need, the next step is to figure out the energy considerations.

Insider Tip

If you have a hard limit of 5,000 BTUs, that means you will need a window unit or portable AC, as central units are more powerful.

Luckily, a 5,000 BTU air conditioner is on the smaller side, so you won’t have to worry and wonder why does my air conditioner run all of the time. Any medium-sized generator should be able to handle it, even if you are comparing Gree vs Midea air conditioners.

Calculating Generator Wattage

Just saying “any medium-sized generator” might not cut it, though, so here is how we arrived at that conclusion. 5,000 BTUs translates to an air conditioner of around 0.42 tons, which requires around 1,000 watts of electricity for power. Medium-sized generators start at around 3,000 watts, so you’ll be able to power your AC with plenty of energy to spare for other appliances. You could even go with a small generator of just 1,000 watts, but that would be cutting it close.

Tips to Conserve AC Energy

Air conditioners are known energy hogs, so here are some tips to keep them in check.

  • Replace or clean the air filters as indicated by the manufacturer’s instructions. You typically need to do this every one to three months, depending on how often you use the AC.
  • Only run the unit when you need it. In other words, turn it off when you leave the house.
  • Consider a smart thermostat that allows you to turn the AC on or off or adjust the temperature when you are not home. These devices also allow you to set schedules ahead of time.

STAT: A 5-ton AC unit generates an outstanding 60,000 BTU of cooling power. This is enough to cool down up to a 3,000-square-foot home. (source)

Generator Size FAQs

Can I connect this AC to solar panels?

Sure, in most cases you can hook air conditioners up to solar panels, provided they maintain enough watts of power to run the air conditioning unit.

How big of a generator do I need to run my whole house?

It really depends on how big your house is to determine the size generator you need. Keep an eye on your running wattage, your exact wattage, and overall energy consumption to determine the watts of power you need.

How AC units are sized?

AC units are sized by the ton or by the amount of BTUs they cool, so when shopping for any size generator, make sure the stats match. Additionally, you may want to use that generator to power other appliances like a sump pump or remote control.
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