Power outages and electrical problems can be unpredictable and inconvenient, especially during hot weather when central air conditioning is crucial.
Fortunately, portable generators offer a solution to keep your home cool and comfortable.
In this guide, we'll delve into the feasibility of powering your central AC with a portable generator and help you select the right size to suit your needs.
We also provide recommendations for top-performing portable generators that are well-suited for this purpose.
Stay with us to the end for all the insights you need!
So, Can I Use My Portable Generator to Run My Central AC?
Yes, a portable generator can power your central air conditioning unit.
Portable generators are not just for powering small appliances; they can keep energy-intensive home systems running during power outages as well.
However, you'll need to pick a portable generator strong enough to run the air conditioning unit and any other essential systems you plan to plug into it.
How Does It All Work?
You often think of portable generators to keep small low-power appliances running when the power goes out.
The reality is one of the most common uses for a portable generator is to keep essential home systems operating when there is an electrical problem at home.
Generators come in a massive variety, differentiated mainly by their electrical production capacity and battery life duration.
The wattage of a generator determines its power output, and the basic rule is to buy a generator with at least a slightly higher wattage output than the AC needs.
Starting Wattage & Running Wattage
When a generator kicks on, it needs more power to begin operations.
Ensure that the wattage output from the generator can handle the higher starting wattage so nothing gets damaged.
You must check these figures for anything else you'd want to power on the same generator to prevent any failures simultaneously.
Be sure to read: How Long Should A Central AC Run At A Time?
Power Transfer Switch
The process of connecting your central AC to a portable generator as a backup needs some careful attention.
If you don't already have a power transfer switch between your furnace and central circuit breaker, you must have an electrician install one.
That way, power can be routed into the system from a generator you can plugin. This step in the process will allow you to connect your generator.
What Size Generator Do I Need to Run a Central Air Conditioning Unit?
To determine the appropriate generator for your central air conditioning unit, consider its wattage requirements.
Here's how to find your AC unit's wattage:
- Identify the tonnage of your unit. It's usually found in the operator manual or manufacturer label using the model number.
- If your unit's capacity is measured in BTUs, divide the BTU number by 12,000 to get the tonnage. For instance, 36,000 BTUs ÷ 12,000 = 3 tons.
- Calculate wattage by multiplying the tonnage by 3,500 (1 ton = 3,500 watts). For example, a 3-ton AC equals around 10,500 watts (3 x 3,500 = 10,500).
Please note this calculation reveals the starting wattage, which is typically 2-3 times higher than the running wattage.
Once you know your AC's starting wattage, you can determine the suitable generator size.
For a 10,500W (3-ton) AC, an 11kW generator is sufficient when powering only the AC.
⚠️ Note: While size can indicate a generator's power, it's not exact. Always consult your unit's wattage for accurate measures to avoid overloading risks.
However, the calculation above only considers a generator for your central AC.
If not, we've outlined other factors to consider in the next section and how to account for them when looking for a portable generator unit.
Determine the Generator Wattage & Appliances Needing to be Run
You also need to identify what other appliances you might run with your air conditioning unit.
Take note of all the starting and running wattage needs and add them together.
Once you have a number that is at least the starting wattage of everything you need to power, you can find a generator with at least that much energy output.
If you're unable to find the exact wattage, we've outlined below the running wattage of the most common household appliances:
| Appliance | Average Running Wattage |
|---|---|
| Central Air Conditioner | 1000-4000W |
| Clothes Dryer | 100W |
| Washing Machine | 500W |
| Dishwasher | 1200-1500W |
| Coffee Maker | 800-1400W |
| Electric Oven | 2150W |
| Microwave | 600-1700W |
| Refrigerator | 100-200W |
| Vacuum Cleaner | 450-900W |
| TV | 40-100W |
How Many Watts Does Central AC Use?
The Central AC unit uses around 3,500 W of electricity or 12,000 BTUs every hour.
To be safe you should pair this average standard with a portable generator that can provide 6,000 to 6,500 Watts of output.
Related article: What Size Generator Do I Need To Run A Window Air Conditioner?
How Do I Connect My Portable Generator to My Central Air Conditioner?
Connecting your portable generator to your central air conditioner can be a simple process when done correctly.
Follow these steps to ensure a safe and efficient connection:
- Determine generator capacity: Check your AC's user manual or manufacturer's label for the total wattage needed. Choose a generator that can meet or exceed this requirement.
- Get a power transfer switch: Have an electrician install a transfer switch to connect your generator safely to your home's electrical system.
- Prepare your generator: Place it on a level surface 15 feet from your home. Check oil and fuel levels.
- Turn off your central AC and main breaker: This prevents back-feeding power into utility lines.
- Connect the generator to the transfer switch: Use an outdoor-rated extension cord rated for your generator's maximum amps.
- Start the generator: Let it run for a few minutes to stabilize.
- Switch on the Transfer Switch: Turn the switch from "Line" to "Generator" to route power from your generator into your home's electrical system.
- Turn on the circuit breaker for the AC: Go to your electrical panel and turn on the circuit breaker for your central air conditioner.
- Turn on your central AC: Your AC should now run on generator power.
- Monitoring: Keep an eye on the generator's fuel levels and don't overload it.
- Turning everything off: When done, turn off the AC and generator, switch the transfer switch to "Line", and restore the main breaker once utility power is back.
What Size Generator to Run 3-ton AC Unit?
A 3-ton air conditioning unit equals 10,500 watts (3 tons x 3,500 watts/ton).
To power this AC unit during an outage, you need a generator with at least 10,500 watts of continuous power.
However, it is recommended to get a generator with additional capacity to handle starting surges and to power other appliances at the same time.
So, a generator with a capacity of around 14,000 to 16,000 watts is advised.
It's essential to check both the continuous and peak wattage ratings of a generator to ensure it can support the AC unit and other electrical loads.
Can a Portable Generator Run a 2.5 Ton AC Unit?
A portable generator can handle a 2.5-ton AC unit, but essential factors apply.
As mentioned, adequate power for the startup is crucial. You'll also need other devices that might be connected to the generator simultaneously.
If the generator's power output barely meets the air conditioner's needs, there might not be enough capacity for additional appliances.
Most recommend choosing a 10,000W generator to power a 2-ton or 2.5-ton air conditioner.
But the good news is that portable generators have developed to power various appliances and systems.
For instance, Generac portable generators can run up to 17,500 Watts of power.
Will a 2,000-Watt Generator Run an Air Conditioner?
A 2,000-watt generator powers small home appliances, including portable or window air conditioning units.
However, it lacks the capacity for central air systems since cooling and distributing air effectively will demand more than 2,000 watts per hour.
What Type of Fuel Do I Need for My Portable Generator?
Portable generators typically run on three main types of fuel: gasoline, natural gas, and diesel.
However, there is now an additional option - solar energy
Each fuel type has its pros and cons, so consider your needs before making a choice.
| Type of Fuel | Pros | Cons |
|---|---|---|
| Gasoline | Widely available and easy to store | Limited shelf life and can be volatile |
| Natural Gas | Clean-burning fuel with a longer shelf life | Require professional installation and are less portable |
| Diesel | Fuel efficiency and less flammable than gasoline | More expensive than gasoline |
| Solar Energy | Renewable resource, require minimal maintenance | Expensive installation |
You might also like: Do I Need A Regulator For My Propane Generator?
What Are the Best Portable Generator to Run My Central Air Conditioner?
If you're looking for a reliable portable generator to run your central air conditioner, here are some of the top options:
Honda EU3000iS
See the Honda EU3000iS on Amazon.
The Honda EU3000iS stands out with its 3,000-watt output, making it an ideal choice for standard central air conditioners.
Its eco-throttle system enhances fuel efficiency, providing a reliable and quiet solution.
Generac GP18000EFI
See the Generac GP18000EFI on Amazon.
For larger central air conditioning units, the Generac GP18000EFI offers a substantial 18,000 watts of power.
Its high power capacity ensures reliable performance, and it features an easy electric start for convenience.
Continue reading: What Is The Best Oil For A Generac Generator?
Champion Power Equipment 100165
See the Champion Power Equipment 100165 on Amazon.
The Champion 100165 offers versatility with dual-fuel capability, providing up to 9,375 watts of power on gasoline.
It's well-suited for most central air conditioners and offers the flexibility to run on gasoline or propane.
You Have Options
Portable generators can take a lot of stress off of your mind as a homeowner.
Power outages or electrical problems are mostly random and unavoidable.
Having a capable generator that can be used as needed to keep your home's essential systems is invaluable.
You just have to keep in mind what power output you need the generator to have to power all the appliances you would need in an emergency.
With a little bit of research and preparation, you can find the perfect portable generator to keep you cool when difficult and unexpected problems arise!
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