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Is Your Generator Capable of Running an AC?


When there is a power outage, the hardest part is being unable to use your air conditioner and feeling uncomfortable in a hot and humid environment. However, people find alternative ways by using a generator to run their AC systems during an outage.

So here’s a question, is your generator capable of running an AC? Some factors will determine whether it will run or not. In this article, we’ll learn more about the generator’s type, size, and capability required to run your air conditioner.

Is My Generator Capable of Running My Air Conditioner?

Your generator can run your air conditioning unit, especially when the power source goes out. However, you must ensure that your chosen generator has sufficient capability to power your AC unit.

Typically, a 4000W generator is required to run a small air conditioner window unit, and a 6000W generator is necessary to run a whole-house air conditioner. Because an air conditioner needs a lot of power, you can only use your generator for one appliance at a time. If you’re considering buying a generator, keep a few things in mind to guarantee you acquire the correct size.

What Size Generator Will You Need to Run an AC?

Before we get into how to run an air conditioner on a generator, you need to consider the size of your generator and AC system. The first and most crucial component is your generator. It is useless if it is too small and you can’t start your air conditioner.

Many homeowners want to reduce the size of the generator because they believe they will never use it. When they require a generator and can’t operate more than a few things around the house, they usually have to settle for only the lights and the fridge. Here are the three suggestions you can consider for the sizes of generators:

4000 Watts

A 5,000 BTU air conditioner is one of the smallest air conditioners you can find, usually fitted directly to a window or a portable conditioner. These are great for cooling rooms up to about 200 square feet.

These conditioners only use around 500W of power, so you should be able to run them efficiently alongside other appliances if you have at least a 3000W generator. It’s essential to note that this air conditioner will not be helpful in large rooms or homes.

However, a minimum generator size of 4000W is recommended if you plan to power your house, parts of your kitchen, and an air conditioner. These are called mid-sized generators and are typically larger than portable devices.

This generator will typically power one standard air conditioner in your home while also powering a few lights and your refrigerator. It is critical to remember that you must start everything sequentially when using a minimum generator size, starting with the fridge, air conditioners, and lights.

6000 Watts

The 12,000 BTU air conditioner is the average size in most homes because it is good at cooling most rooms. To power this large air conditioner, you will need at least a 4000W generator that is not operating too many other appliances.

When operating many power-hungry appliances throughout your home, remember that each one uses more electricity to start up than it does while running. A fridge or TV only uses maximum power when turned on, whereas air conditioners always draw nearly total capacity.

However, it is recommended that you have a generator capable of producing at least 6000W of power. It keeps the generator from being overworked while the system attempts to cool your home without consuming power from other appliances.

10000 Watts

If you want to power your entire house, keep everything cool or hot, keep the kitchen running, and have power for a cup of tea, your generator must be significantly larger. For this, it is recommended to have a generator capable of producing at least 10000W of power.

Although it may appear extremely high, a generator of this capacity will readily and comfortably run the average household while still having enough power to withstand spikes. Furthermore, a generator of this capacity can run many air conditioners while providing enough electricity for other household equipment.

Why Do I Need Stronger Generators to Run an AC?

Usually, a device that is cooling down or functioning will typically spike once it has started to turn the motor on. This is how your fridge operates in your home, with the motor requiring a significant amount of power to start rotating and then utilizing less once it turns.

Meanwhile, air conditioners are different because the fan and motor push the coolant through, switching on and off as needed. This means it will need to use the maximum amount of power randomly to keep the space at the right temperature.

That is why your generator usually dies more frequently on cooler days. An air conditioner stays on when it is hot but turns off and on when the room has reached a comfortable and cold temperature.

What Is the Best Way to Run an AC on a Generator?

It is essential to examine your home now that you know the size of the generator you want. You can take a few more measures to cool your house properly. An air conditioner cannot frequently run when powered by a generator since it is misused for the system.

It would be best to take these precautions when the power goes out and you can’t stand the heat of your surroundings. Let’s take a closer look at these measures to ensure that you do not overload your generator and that your air conditioning unit operates well:

Operate Your Air Conditioner When Necessary

The most important advice for using an air conditioner is only to use it when needed. Operating your air conditioners even when no one is in the room for several hours wastes energy.

When using a generator, we recommend that all air conditioners be switched off, and everyone work in the same room. This enables maximum efficiency because an air conditioner in that room can comfortably cool it without competing for electricity with others.

Not Constantly Turning On and Off

Some users still turn their air conditioners on and off several times every hour. This habit consumes a lot of energy but is wasteful and damaging when powered by a generator.

An air conditioner should be turned on or off to do its job or allow natural air to flow through your home. It can’t be stressed enough how much energy you waste by turning on and off an air conditioner to cater to people’s preferences.

Adjustment of Temperatures

If it’s hot outdoors, you should know that using an air conditioner to cool the area below 20°C would consume significantly more power. Adjusting an AC system to cool down to roughly 25°C will be far more efficient in the long term and allow the generator to function more comfortably.

If it’s cooler outside but still feels hot indoors, consider allowing more natural air into your room, as running an air conditioner to cool space at 20°C wastes energy. Typically, you will not turn off the system after a few minutes because it significantly cools the area.

Close Windows and Doors

Some people open their doors or windows while an air conditioner is running. It directly undermines the system’s function and causes it to use far more power as it attempts to cool a much greater area constantly flooded with hot air. If you need to keep your windows and doors open while your air conditioning is on, consider moving your AC unit to a place without open vents.

How Do You Calculate the Power Consumption of an Air Conditioner?

Calculating how much power an air conditioner would require at its maximum capacity can be challenging. Fortunately, there is an accepted standard for these units that is sometimes precise but allows you to calculate how much power they require quickly.

Typically, you can calculate how much power it will need by removing one zero from the total BTU of an air conditioner. This means that a 5,000 BTU air conditioner will use roughly 500W of power at peak when in use, with the unit rarely exceeding this figure.

However, air conditioners consume a lot of electricity, sometimes even more than their direct rating. A 5,000 BTU air conditioner in a large room or with open windows can use up to 600W of power to cool everything.

Final Thoughts

We hope this article has helped you understand the capabilities of your generator to power your air conditioner. If purchased and maintained correctly, your generator can comfortably run an air conditioning system throughout your home. It is critical to remember that you must find a balance that allows a generator system to collaborate to provide and use the correct power levels.

JP Reyes

JP has been in the aircon industry for almost as long as he has been alive. As a child JP would help his tatay fix aircon units at their junk shop in Cavite. After graduating UP in the early 2000's, JP then started his own Aircon servicing business and within 5 years had 10 shops in 8 different cities. Fast forward to today and JP brings all his experience and expertise online to give readers trustworthy advice and reviews about Air-conditioning buying, servicing, cleaning and repair in the Philippines.

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