How many watts does a 5000 BTU AC use?

The precise wattage of a 5000 BTU air conditioner depends on the Energy Efficiency Ratio (EER) of the unit itself, which means different units will have different power requirements.

In this article, I’ll discuss the power requirements of these units, and I’ll show you a couple of ways to determine the wattage of your unit. In addition to that, I’ll later show you how to estimate and measure the energy consumption of these units.

How many watts does a 5000 BTU AC use?

On average, a 5000 BTU air conditioner uses 450 to 500 Watts of power when it’s running. At 115 Volts, these units draw around 4 amps of current (around 40 amps at 12 Volts). However, some units that have a high EER (or CEER) rating of 12 or more, will use around 400 Watts of power.

There are many ways to determine the specific wattage of these units. The easiest way is to look at the technical specification label, which is usually stuck somewhere on the unit.

In the specification label, look for the wattage rating specified in Watts (W). This rating can be labeled as Watts, Rated Input, Power Input, Rated Power, etc…

How many watts does a 5000 BTU AC use

If the wattage is not specified, look for:

  • The amperage: this rating is measured in Amps (A) and is usually labeled as Amps, Current, Rated Amps, Rated Current, Current Input, etc…
  • The voltage: appliances in the U.S. are generally rated at 115-130 Volts. Look for the voltage rating in Volts (V)

At 115 Volts, the Amperage of a 5000 BTU unit should be between 3.5 and 5.5 Amps. Usually, these units are rated at around 4 Amps. Once you find the Amps and Volts of your unit, you can calculate the power rating of your unit by using this formula:

Watts = Amps x Volts

Even if you don’t yet own the unit, these pieces of information are usually provided by the manufacturer or the retailer.

Another way to estimate the power usage of these units is to use the EnergyGuide (yellow) label that comes with the AC. In the label, you’ll find an Energy Efficiency Ratio (EER), or a Combined Energy Efficiency Ratio (CEER) for new units.

How many watts does a 5000 BTU AC use

You can then calculate the rated wattage of your 5k unit by dividing its capacity by the provided CEER (or EER) rating:

Power Rating (Watts) = Capacity (BTU)  ÷ CEER (or EER)

Power Rating (Watts) = 5000 BTUs  ÷ 11

Power Rating (Watts) = 454.5 Watts

If none of these labels is provided, and you can’t find information about your unit on the web, you can use an electricity monitoring device such as the Kill-A-Watt or the Poniie meters.

You can use one of these devices by plugging it into the wall socket (or inverter) and plugging your air conditioner into it. The device will display the exact power usage of your unit.

Here’s a video of a 5000 BTU unit plugged into a Kill-A-Watt meter:

In the video, you can see the power usage of the unit in Watts. However, these devices are even more useful when it comes to measuring energy consumption (in Watt-hours), which brings us to the next section.

How much energy does a 5000 BTU air conditioner use?

While power is measured in Watts, electrical energy is measured in Watt-hours (Wh) or kiloWatt-hours (kWh), with 1 kWh equal to 1000 Wh.

The energy consumption of a 5000 BTU AC depends on many factors, such as the outdoor temperature, the age of the unit, insulation, etc… However, on average, these units consume 300 to 400 Watt-hours of energy per hour.

The following table provides estimates of the energy consumption of 5000 BTU air conditioners based on their run time:

Run time Energy consumption in Watt-hours (Wh)
1 hour 350 Wh – 450 Wh
2 hours 550 Wh – 700 Wh
3 hours 800 Wh – 1000 Wh
4 hours 1050 Wh – 1250 Wh
6 hours 1600 Wh – 1900 Wh
8 hours 2200 Wh – 2600 Wh
10 hour 2700 Wh – 3200 Wh
12 hour 3200 Wh – 3800 Wh
16 hour 4400 Wh – 5000 Wh
Energy consumption of a 5000 BTU air conditioner

Since air conditioners don’t really run 100% of the time when they’re on, estimating their energy consumption can be a little confusing.

This is because energy consumption is measured/calculated by multiplying the power usage of an appliance, by its usage time:

Energy Consumption (Wh) = Power Usage (W) x Usage Time (hours)

A simple example:

Let’s consider a light bulb that is rated at 50 Watts. If this light bulb is left on for 5 hours, its energy consumption can be calculated as such:

Energy Consumption (Wh) = Power Usage (W) x Usage Time (hours)

Energy Consumption (Wh) = 50 Watts x 5 hours

Energy Consumption (Wh) = 250 Watt-hours

Over 5 hours, our 50W light bulb is obviously on all the time and consumes about 250 Watt-hours (0.25 kWh) of energy. However, when an air conditioner is left on, its compressor doesn’t necessarily run all the time.

Most 5000 BTU air conditioners are of the non-inverter type, which means they run at full capacity when they’re turned on, and the compressor automatically turns off after the set temperature is reached. After that, these units will turn ON and OFF in a way that maintains that set temperature.

The percentage of time for which the air conditioner is really ON is referred to as Duty Cycle (%). And this duty cycle will mainly depend on the temperature. As a result, the energy consumption formula becomes:

Energy Consumption (Wh) = Power Usage (W) x Usage Time (hours) x Duty cycle (%)

For example, given that the room has a square footage of around 150 square, the AC unit will require about an hour to cool down the room when it’s first turned on. During this first hour, the unit will run almost 100% of the time and will consume 400 to 450 Watt-hours of energy.

Once the room is cooled down, the unit will only run for about 50-80% of the time (depending on the temperature and insulation) and will consume about 200-250 Watt-hours of energy per hour.

As a rule of thumb, during a 5 hour period, you could say that the air conditioner has an average duty cycle of about 70%. The higher the temperature, the higher the duty cycle. Also, the worse the insulation, the higher the duty cycle.

As another rule of thumb, with temperatures around 90°F, you’ll probably be looking at a duty cycle of about 75%. With temperatures above 95°F and average insulation, you’ll probably be looking at a duty cycle of about 90%.

For example, let’s say that the AC is rated at 450 Watts, and let’s use 80% as our duty cycle. We can estimate the energy consumption of our AC over 5 hours as such:

Energy Consumption (Wh) = Power Usage (W) x Usage Time (hours) x Duty cycle (%)

Energy Consumption (Wh) = 450 Watts x 5 hours x 80 %

Energy Consumption (Wh) = 1800 Watt-hours

According to our calculations, this 450W AC unit would consume 1800 Watt-hours (1.8 kWh) of energy over 5 hours, which is equivalent to about 360 Wh/hour.

But again, for more precise measurements, you’ll need to use an electricity monitoring device that can measure its energy consumption over time.

For example, if you’re in the habit of using the AC 8 hours a day, you could plug it into the wall (or inverter) via a Kill-A-Watt meter and the device will measure the exact amount of energy consumption over those 8 hours.

How many watts does a 5000 BTU AC use

After turning your AC on, push the button that says KWH (purple button), and the device will display the energy consumption.

Frequently Asked Questions

How much battery power is needed to run a 5000 BTU air conditioner?

The amount of battery power required to run these units will depend on their usage time and the energy they consume during this time. But it will also depend on the type of batteries you’ll be using.

For example, to run a 5000 BTU AC unit for 3 to 4 hours, you would need a 12V-100AH lithium battery or 2 12V-100AH lead-acid batteries. To run it for 7 to 8 hours, you would need double the amount of battery capacity.

Click here for more details.

Will a 3000 watt inverter run a 5000 BTU AC?

A 3000 Watt inverter can run a 5000 BTU air conditioner. However, unless the inverter is running other appliances as well, its efficiency is likely to be very low. If the 5000 BTU unit is the only load running on the inverter, the inverter should be rated at 1500-2000 Watts.

It is also important to note that the inverter should be of the Pure Sine Wave type.

Click here to learn more about this topic.

How many solar panels to run 5000 BTU AC?

The exact amount of solar power that you need to run a 5000 BTU air conditioner will depend on the daily energy consumption of the unit, and on your location.

Assuming it runs for 8 hours a day, as a general rule of thumb, you would need 600 Watts of solar power to run a 5000 BTU air conditioner. However, you would also need a solar charge controller, a battery bank, and an inverter.

Click here to learn more about these components and how to size them correctly.

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Hi! My name is Younes. I'm an electrical engineer and a renewable energy enthusiast. I created with a mission of delivering digestible content and information to the people who seek it.

One comment

  1. Thank U for the info l have read about solar and battery bank storage needed to run a 5000btu ac. The house I’ve lived in for many years in Oregon sold and l have 90 days to move. I’ve decided to live the rest of my life off-grid at 65 years old. It’s a little scary with only $860.month Social Security and less than $2000. remaining in savings. I found a place in Arizona to live off grid. I have already purchased 300watts of solar panels, 2200watt pure sine propane/gas generator for backup and a 1000watt inverter.. After reading your article l see l bought the wrong size Renogy inverter though.
    Thanks, Bob

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