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Can A Portable Generator Power Your Central Air Conditioner?

    Each year there are times of hot weather and storms that can bring about black-outs. Summertime is usually a peak season for tropical storms that will knock out your power and leave you sweltering in unimaginable heat.

    With the power out and your air conditioner not working, you can only look forward to when the power eventually comes back on and you can feel cool again.

    Rather than standing in a cold shower to cool off when this happens, why not use a portable generator to get your central air conditioning back up and running?

    Can you even power your central air conditioning with a portable generator? Of course, you can, but you have to get one that can do so, taking into account the wattage requirements of your air conditioning system. 

    Portable generators provide the ability to keep your appliances powered in your time of need. 

    Can A Portable Generator Power Your Central Air Conditioner

    How many watts does central AC need? 

    When looking at the wattage of your central AC unit you need to consider both starting watts and running watts. Simply put, starting watts is how much power it takes to start up the generator. Whereas running watts is the amount it requires to keep the appliance running. 

    When you are powering an appliance through a portable generator, you want to ensure that you avoid electrical harm or malfunctions. You can avoid this by ensuring that your generator’s power is higher than that required by the appliance.

    For example, if you were to power something that requires 2400 Watts then a generator that outputs 3000 Watts is best, or if your appliance required 9000 Watts, a 7000 Watt generator would not cut it but a 10,000 Watt generator would.

    If you used a generator that did not have a power higher than the appliance then you would see that either your system would not work, or you may damage your home’s electrical system. 

    Many of the largest portable generators available today have the capacity needed to start and run an average central AC system.

    However, even if you think your generator is capable, you should always do the math just to ensure that it is safe and powerful enough to avoid those power problems or electrical faults. 

    Not only do you want something powerful enough to keep your AC running, but there is no harm in going a little higher.

    If you buy a generator that works at 10,000 Watts, and your AC requires 6,000 starting watts and 5,500 running watts, then you have enough power left over to power up your refrigerator, your tv, and some other appliances as well. 

    So this is a very beneficial move to make if you are looking for a generator that will be a worthy assistant in times of power outage. 

    How many watts should your generator be?

    Your generator should have enough power to keep your AC running for as long as you need it to. The average central air conditioning unit will require 3000-5000 Watts to provide a cool air supply to your home for up to 9 hours.

    Therefore, your generator should ideally be around the 5,500 to 6000 Watt range. But, if you want to be able to power up your other appliances then we would recommend getting something a bit higher. 


    DuroMax XP15000E Gas Powered Portable Generator

    [amazon fields=”B075V1G5QZ” value=”thumb” image_size=”large”]

    If you are looking for something that will be able to power up your whole house in the event of a power outage then this generator is a good shout. It provides 15000 Watts, meaning it can easily power your AC, refrigerator, freezer, TV and more with ease.

    15000 Watts of power means that you do not need to choose what to power up when a blackout occurs, you can keep most of your appliances up and running without any worry. 

    It provides 15000 peak Watts and 12000 running watts. This generator is also approved for use in all 50 states, so there is no cause for concern at all. DuroMax makes fantastic generators and this has to be one of their best, providing exactly what you need when you need it most. 

    If 15000 Watts is a bit on the heavy side for you then there is always their 10000 Watt model, which will still power up your central air conditioning and a few other items as well, just perhaps not as much as the 15000 would be able to. 

    It is also fitted with a Low-oil shut-off to protect your generator but automatically shutting off when it senses oil is low. It also offers idle-control, which means that it lowers its RPM when not in use, which saves fuel and reduces any noise. 

    If you aren’t sure what generator to get for your home central air conditioning, we recommend this one.


    We don’t all know the difference between starting and running wattage, aside from the obvious, that one powers the start of the appliance and the other runs it.

    But how much does it differ and what do you need to take into consideration when buying a generator for something as power-hungry as your central AC unit? 

    The most significant number out of these is the starting wattage. Most central AC units need a rather high wattage to start up, this can sometimes excel the running wattage by 1000 Watts or more.

    When you are looking for a generator, you must take the starting wattage into account more, it must be able to handle the starting wattage. 

    If you are not 100% certain of how much wattage your AC unit requires, you can look at the nameplate or check with the manufacturer.

    You must never guess this as if you try to power something that requires more power than your generator can provide you will risk overloading it. The worst-case scenario as a result of the overload is that the overpowering would result in a fire. 

    There is no real average wattage for central air conditioning units. This is because more modern energy-efficient units may need only 2000 Watts, while older ones that are less efficient could require up to 10000.

    So while the average overall is around 5000 Watts, there can be extremes on either end. This is specifically why you need to check the wattage requirements of your generator. 


    Perhaps you are thinking that powering a central AC system may be a bit too much of a hassle, requiring too much power.

    Maybe you already have a lower wattage generator and don’t want to have to invest in a new one just to power your AC unit. That is why there are alternative options. 

    There is the option of setting up some fans and powering those through a generator, which is not a bad idea, but the downside is that fans tend to just blow around the air already available, in this case, that air would be the warm air.

    So this technique would not offer you the cooling that you seek. There is one other option though. 

    Window AC Unit

    If you don’t want to power a whole central AC unit and fork out the extra money for one of those, and if the fan idea just does not sound like what you need.

    You can always power a window AC unit with your generator. These require much less power than a central AC unit, but you do still need to do the math. 

    Even with this type of AC unit you still need to check both the starting and running watt requirements. Window AC units tend to require power about the 2000 watt mark- which is significantly less than a central AC system.

    So, if you were to use a generator with 3000 watts, and your AC had a startup 2500 and a running 2000, you would just make it. Although this would leave little room to power anything else in your house.

    That is why we always recommend getting a generator that has more power so that you can power more when normal power fails. 

    If you wanted to go even smaller though you could get a much smaller window AC, as these often run at a wattage below 1000. Check your generator and check your AC to make sure they match up. 

    Here are some examples of power matches that we would recommend.

    A window air conditioner just below 1000 watts matches nicely with a generator that runs at 2000 watts. It leaves just enough room for other minor appliances to be powered as well in a more affordable range.

    Window AC below 1000WattsTCL 12W3E1-A 12,000 BTU window air conditioner

    Gas Powered Generator 2000 Watts WEN 56200i 2000-Watt Portable Inverter Generator

    Lower wattage Generators

    You may be looking at the possibility of investing in a generator that produces around 6500-7000 Watts. This generator size may likely power most residential AC units, for the summertime or black-outs.

    As usual check the required wattage of your AC unit to make sure that a generator of this size has enough energy to power it. 

    Ensuring a safe connection 

    Whatever you do, ensure that your power connection is safe. Most of the time the connection will be made via the circuit breaker box, this will be fitted with a transfer switch connected to it, this is where the generator will be plugged into. 

    Ensure that your setup is installed and maintained correctly, safety comes first when dealing with any electrical appliances and components.

    If you are running an extension cord from your generator to an appliance, do ensure that the cord is damage free. Ensure this to be certain that your appliance will run both efficiently and safely.