What Size & Wattage Generator Do I Need to Run My Air Conditioner?

Before buying a backup generator for providing power to the air conditioner during a power outage you need to look into a lot of factors, one of them being the size of the generator. this article will clear your doubts based on which size and wattage of generator you should use to run an air conditioner. 

What size of generator is needed to run an air conditioner? 

  • A standard air conditioner approximately needs 1000 watts for that you need to run a generator that is able to provide the wattage of 1000 watts.
  • If the AC is required to use for an hour or two every day then you required a generator that is able to provide 500 watts of power. 
  • If you are using the air conditioner for long periods for example 8 hours each day then you need a generator which is able to provide at least 2000 watts of power

There are various things to be considered to find out which size of generator to run an AC such as:

  • Firstly you should look for the wattage consumed by an air conditioner that can be seen on the label mentioned AC. A typical window air conditioner does need a wattage of upto 1000 watts. 
  • The second point you need to check is the start-up wattage which means the power that the AC requires at the starting stage because the power consumed will always be higher than the power consumed at the running time. You can determine the startup wattage on the AC unit itself or on its manual of it. 
  • The third point is to look at the surge wattage as it is the amount of power which is required to run an AC unit and it is not required continuously

Types of generators:

There are two types of the generator such as:

  • Portable generator.
  • Gas generator. 
  • Diesel generator. 
  • Standby generator. 

Portable generator:

The portable generator and compared to the standby generator are less expensive and you can transport The generated from one place to another place.


Standby generator:

They are more expensive than other generators and it is used by connecting the electrical system of the house to the generator which is placed outside the home. They are also called permanent or stationary generators because they cannot be moved easily from one place to another after fixing them. 


Gas generator:

The gas generator is less expensive than the diesel Or portable generator and does have a longer running time. 

Diesel generator:

These generators are good to handle heavy loads of appliances. 

Portable generatorStandby generator
1. The average cost of a portable generator is from $500 to $2000.
2. If the power is from the portable generator do require manual startup. 
3. Is able to provide power to some of the home appliances. 
4. It does not require regular maintenance. 
5. No price for installing the generator. 
1. The average cost of a standby generator is from $3000 to $5000.
2. If the power goes out then it will automatically startup. 
3. It is able to provide power to the entire home. 
4. It does require regular maintenance. 
5. It cost $2000 to $4000 for installing the generator. 

List of the best generator to run an air conditioner:

The following are the best generator to run an air conditioner:

  • Duromax XP15000E gas-powered portable generator.
  • Champion Power 3500W equipment portable generator. 
  • WEN GN6000 6000-watt portable generator. 
  • Champion 3400-watt portable generator. 
  • Buffalo tools GEN1001-watt inverter generator. 

Duromax XP15000E gas-powered portable generator:

  • This generator is powered by the V twin engine and offers power upto 12000 running watts.
  •  The engine which is used in this generator is able to produce 23 horsepower which is considered a huge amount for using the generator for home and job sites.
  • It has an operating volume of 74 DBA which is common for most generators.

The generator does have four outlets such as:

  1. 120/240V 50A heavy duty outlet
  2. 120V 30A twist-lock outlet
  3. 120V 20A GFCI outlet
  4. 120/240V 30A twist-lock outlet. 
  • The fuel tank of the generator is 10.8 gallons which can approximately Run for 9 hours at 50% load. 

Champion Power 3500W equipment portable generator:

  • The engine used in this generator is embedded with 224 CC which can produce the power of 3500 running watts which is very much to run an air conditioner. 
  • The champion power generator is able to start and run an air conditioner of 15000 BTU.
  • The operating volume of the generator is up to 68 DBA. 
  • The size of the fuel tank of the generator is up to 3.4 gallons which can be used for 10.5 hours when it is used at 50% load. 

It consists of 4 outlets such as:

  1. Two 120V 20A household outlets
  2. One 120V 30A locking outlet
  3. One 120V 30A RV.

WEN GN6000 6000-watt portable generator:

  • This is considered one of the most affordable generators which consist of many features. 
  • The generator is embedded with a 272 cc OHV engine and 4 strokes. 
  • The generator is able to produce 500 running watts which is sufficient for running an air conditioner.

It consists of six outlets:

  1. One 12-Volt DC outlet
  2. 2 standard household outlets (5-20R)
  3. One 120-Volt/240-Volt L14-30R outlet
  4. One 30 Amp TT-30R RV outlet
  5. 120-Volt to 240-Volt voltage selector.

Champion 3400-watt portable generator:

  • The champion generator is 3400 watts and is a dual-fuel generator that can run on propane or gasoline.
  • The generator is able to produce 3100 running watts
  • The generator is powered by an engine of 192cc 4 stroke air cooled single cylinder engine. 
  • The operating volume of the generator is upto 58 dBA. 
  • The size of the fuel tank of the generator is 1.6 gallons and is able to run for 7.5 hours with gas at 25% load and 14.5 hours with propane at 25% load capacity. 

It consists of four outlets:

  1. Two 120V 20A outlets
  2. 120V 30A RV outlet
  3. 12V USB port.

For selecting which size of the generator unit to run for an appliance or more than one appliance you need to know the wattage required by various appliances

The wattage required by appliances for starting and running:

AppliancesStarting WattageRunning wattage
Refrigerator/ freezer
2-ton central AC
Electric water heater
Total wattage

Hence we can say that for running all the essential appliances we need a generator of at least 25 kilowatts. 


After reading the above article it is clear what size of generator we should use to run an air conditioner. And if the person doesn’t know about the running power of the generator and overloads the generator it will automatically shut down or overhead which can destroy or damage the generator or the home appliances. 


Rick Costa

Leave a Comment