9 Best 12000 Watt Generators: Shopping Guide & Things to Consider

In general, this type of machine can run almost any essential household appliance, including:

1. Fridge with a freezer
2. Sump pump
3. Water pump
4. AC unit
5. Heat pump
6. Furnace
7. Medium radiant heater
8. All smaller electric appliances
9. A majority of power tools

Whether you can run all these at the same time you need to know the power consumption of each appliance in your home. Also, you need to know whether your generator has the correct number and type of outlets as some higher wattage appliances such as AC units may need different outlets than other low-wattage devices.

Just don’t expect to run your whole house on this machine simultaneously as in some cases, a 12,000-watt generator will not have enough power. We have provided tables with rough estimates for individual electric appliances in this article.

If you need to provide an energy backup for your whole house without any limitations, you may consider getting a standby unit instead of a portable one.

Usually, these are much more expensive and need to be installed by a professional electrician.

In general, a 12,000 running watts generator should provide enough power to run a heat pump or electric furnace. However, answering this question is really hard without knowing the exact running and starting watts required by your appliance.

Please, contact a manufacturer of your pump or furnace to learn more info on its wattage requirements. Also, we have discovered a forum thread where this question is answered in more details so don’t forget to check it out.

In most cases, a 12,000 generator should provide enough power to run a welder. Sadly, the answer to this question is not that simple. To learn, whether you can run your welder on a 12,000-watt portable generator, you need to know the power requirements of your welder (see the data tag or user manual you got to your welder).

However, based on the information we were able to learn, the best option is to get a special generator that has been manufactured for welding purposes to be able to harness the full potential of your welder.

You can see some good options on Home Depot.

In general, a 12,000 – 13,500 running watts generator provides enough power to run an air compressor without any issues. However, answering this question is really hard without knowing the exact running and starting watts required by your air compressor.

We have found rough estimates for different types of compressors:

• 1/2 Horse Power – It takes 975 running watts and 1600 starting watts.
• 1 Horse Power – It takes 1600 running watts and 4500 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your compressor.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)e

Usually, a 12,000 – 13,500 running watts generator should provide enough power to run almost any sump pump without issues. However, answering this question is really hard without knowing the exact running and starting watts required by your pump.

We have found rough estimates for different types of sump pumps:

• 1/3 Horse Power – It takes 800 running watts and 1,300 starting watts.
• 1/2 Horse Power – It takes 1,050 running watts and 2,150 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your pump.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

Just keep in mind that your sump pump will probably require a 240V outlet on your generator.

In general, a 12,000 – 13,500 running watts generator should provide enough power to run almost any well pump without issues. However, answering this question is really hard without knowing the exact running and starting watts required by your water pump.

We have found rough estimates for different types of pumps:

• 1/3 Horse Power – It takes 750 running watts and 1,500 starting watts.
• 1/2 Horse Power – It takes 1,000 running watts and 2,100 starting watts.
• 3/4 Horse Power – It takes 1,500 running watts and 3,000 starting watts.
• 1 Horse Power – It takes 2,000 running watts and 4,000 starting watts.
• 1 & 1/2 Horse Power – It takes 2,500 running watts and 5,000 starting watts.

As you can see in the estimates above, the issue is not running watts but starting watts. To get the precise numbers, you will need to find the voltage, amperage, and horsepower information on the info-plate of your pump.

Then, all it takes to learn required wattage is to apply this equation:

Watts (W or kW) = Volts (V) x Amps (A)

Based on our knowledge, you should be able to run a central air conditioning unit with a 12,000-watt generator especially if you get a “hard start kit” for your AC. However, the answer to this question really depends on the number of running and starting watts your AC unit requires.

Obviously, these numbers vary from one unit to another and are based on the cooling ability of individual models and brands. That is why you need to look for the following data at the name tag of your central AC unit:

1. LRA (Locked Rotor Amps) – This number represents the current you can expect under starting conditions when you apply full voltage.
2. RLA (Rated Load Amps) – This number represents the maximum current a compressor should draw under any operating conditions.
3. FLA (Full Load Amps) – This number represents the same as the Rated Load Amps.

You need to take into consideration the amps for both the compressor and the fan unit. To determine, if your 12,000-watt generator can run a central AC, please consult its manufacturer or a professional electrician.

Keep in mind that a typical central air unit runs on 208/240 volts and is often permanently mounted and hardwired into the electrical system of your house. That is why to safely run this electronic appliance you need to connect your generator through a transfer switch.

Actually, you should always connect your generator through a transfer switch if you don’t want to damage your appliances or endanger people who may be working on electric lines in your neighborhood.

In general, a 12,000-watt gasoline generator has a 4-stroke engine. If this is the case, you will need to use either SAE 30 (if you live in a warmer climate) or an SAE 10W-30 if you are going to use it in a colder climate (do not forget to double-check with your owner´s manual).

Also, some machines of this size include an oil filter that needs to be replaced as well.

However, there are several things you need to consider while choosing the oil for your machine:

• Whether you got a 2-stroke or a 4-stroke engine
• Starting and operating temperatures
• Type of fuel your generator runs on
• Certifications and classifications of the oil
• The reputation of the brand and company producing the oil

If you need to learn more information on how to choose the best oil for your generator, then consult our guide that is available right here. We provide you also with a list of best brands in various categories of lubricants.

In general, a 12,000-watt generator provides approximately 100 amps, in case of 120 volts or 50 amps in case of 240 volts. To learn more, you should check out the owner´s manual to the machine you want to buy.

Actually, identifying how many amps there are in a 12,000 running watt generator is a straightforward process. All you have to do is to apply the following formula:

Amps (A) = Watts (W or kW) / Volts (V)

You need to divide the wattage by the voltage. So in this case, you need to divide 12,000 by 120 or 240 to get the correct numbers.

Although this question doesn’t have a universal answer as each generator has unique fuel consumption and capacity of the fuel tank, based on our database, an average 12,000 – 13,500 generator runs for approximately 9.15 hours on a 50% load.

This number is a median that we got after looking at the run time of over 13 generators that provide 12,000 – 13,500 running watts.

There is not a single correct answer to this question. Actually, there are several features of your 12,000-watt generator you need to consider while choosing your transfer switch.

We will be doing a guide on choosing the best transfer switches soon but in the meantime, consider this guide from Electric Generators Direct.

If you are looking for an RV generator, our advice is to choose a machine that is powerful but still quiet. Sadly, there are no inverters in this category of generators and machines of this size are noisy in general.

At least there are some 12,000 generators that provide RV ready outlets, such as:

1. Westinghouse WPro12000 (1112+ Reviews)
2. A-iPower SUA15000E

If you want to get a generator that doesn’t come equipped with an RV ready outlet, you need to get a necessary set of adapters (also called dogbones) to easily connect your RV to any machine on this list through either a 20, 30 or 50 amp outlets.

So pick a generator that fits your needs the most and if it isn’t RV ready, don’t forget to get the correct adapter.

While going over our database of 12,000 – 13,500 running watts generators, we haven’t identified any machine that runs on diesel. If you still need a diesel powered generator, you would need to decrease the running watts category significantly:

• Boss DY8500LN-D (8,300 running watts generator)

Just expect to pay a lot as diesel generators are usually on a much more expensive side when compared to gasoline-powered machines.

There is only one 12,000-watt generator that is able to run on propane – the DuroMax XP15000EH (dual fuel unit – gasoline/propane). It is a good generator that will not ruin your budget.