# How much power does an RV AC use? A guide to RV air conditioners’ power usage

In this article, my goal is to offer a straightforward explanation of how RV air conditioners consume electricity.

To achieve this, I’ll start by clarifying the different aspects of your RV AC’s electricity use, specifically its Power Usage (measured in Watts) and Energy Consumption (measured in kWh). I’ll highlight the distinctions between these two terms and explore their interconnection.

Next, I’ll break down each of these aspects, discussing them individually and guiding you on how to accurately calculate them.

Let’s get started.

## Understanding Electricity Consumption: Power vs. Energy

To understand the electricity consumption of your RV air conditioner, you’ll first need to understand how that electricity consumption is measured.

There are 2 main units that matter the most when trying to measure the electricity usage of an air conditioner: kWh and kW, and although they look similar, they measure two different aspects of electricity, and should not be used interchangeably.

• kWh: This stands for kiloWatt-hours and is equal to 1000 Wh (Watt-hours). kWh and Wh are the conventional units for measuring Electrical Energy. For example, we can say that an RV air conditioner consumes 10 kWh (or 10,000 Wh) per day, or a solar panel produces 1 kWh (1000 Wh) per day.
• kW: This stands for kiloWatts and is equal to 1000 W (Watts). kW and W are the conventional units used to measure Electrical Power. For example, we can say that an RV AC unit is using 1000 Watts of power at a given moment, or, a solar panel is producing 120 Watts at a given moment.

The difference, or rather, the relationship between kWh (Energy) and kW (Power), is that Power measures the rate at which Energy is being transferred (consumed or produced). This relationship can be expressed as follows:

Energy (in Wh or kWh) = Power (in W or kW)  x Time (in hours)

For example, if a TV continuously uses 30 Watts of power and is left on for 10 hours, it could be said that the TV consumed 300 Wh of energy during those 10 hours (30 Watts x 10 hours).

If the same TV is only left on for 30 minutes (0.5 hours), it could be said that it consumed 15 Wh during that 30 minutes (30 Watts x 0.5 hours).

Learn more about Energy (kWh) and Power (kW), and the difference between them here.

There are 2 more units that measure electricity, which would be useful to know about. These units are Amps (A) and Volts (V), which respectively measure Amperage (Current) and Voltage (Potential).

Learn more about Amps and Volts here.

Now, there is a relationship between Power (Watts), Current (Amps), and Voltage (Volts), and this relationship is expressed as follows:

Power (in Watts) = Amperage (in Amps)  x Voltage (in Volts)

For example, if an air conditioner operates at 120 Volts, and is rated at 10 Amps, the power rating (wattage) of the air conditioner can be calculated as such:

Power (W) = Amperage (A)  x Voltage (V)

Power (W) = 10 A  x 120 V

Power (W) = 1200 Watts

Power (kW) = 1.2 kilo-Watts

Now that we’ve covered the basics, let’s dive into the electricity requirements for RV air conditioners.

## How much power does an RV air conditioner use?

The amount of power that an RV AC uses will mainly depend on the cooling capacity of the air conditioner, which is measured in BTUs (British Thermal Units). The higher the BTU rating of the RV AC, the more power (watts) will be required to run it.

Typically, RV air conditioners come in 13,500 or 15,000 BTU ratings. Air conditioners in this range usually operate at 1,300 to 1,500 watts, although in some instances, they might peak at 1,800 to 2,000 watts during normal operation.

However, during the initial startup phase, the power requirements of these air conditioners may surge and potentially reach up to 6,500 – 8,000 Watts.

This brief surge during startup is generally not a concern when running the AC on shore power. But if you plan to use an inverter or a generator to power your RV AC, the starting wattage becomes a critical consideration.

For larger RVs equipped with two air conditioners, such as 5th wheels, travel trailers, and motorhomes, the combined cooling capacity typically ranges from 27,000 to 30,000 BTUs.

If both air conditioners are running simultaneously, their power draw during normal operation could go up to 3,500 to 4,000 watts, but it can briefly spike to 8,000 to 10,000 watts when one AC starts up while the other is already running.

To visualize this, here’s a table that estimates the Power (Watts) and Current (Amps) requirements of RV air conditioners based on their BTU ratings:

It’s important to note that the values in the table are rough estimates, giving you an idea of how much power (in watts) and current (in amps) these RV air conditioners might potentially need during regular operation and when starting up.

While these estimates were calculated based on the typical electrical characteristics of these air conditioners, please keep in mind that the actual power consumption of your RV air conditioner depends on the specific model and its electrical specifications.

Let me explain how you can use the electrical specifications of your RV air conditioner to determine its power requirements.

The RV AC nameplate, often attached to the side of the unit on the roof, holds all the details you require to find out how much power your AC uses.

When you find it, if it doesn’t directly state the rated power usage in Watts, check for the Amperage and Voltage specifications.

The Amperage ratings of the air conditioner will usually be specified in Amps (or A for short) under RLA and/or FLA.

RLA stands for Rated Load Amps and refers to the maximum amount of electrical current (in Amps) that the compressor should draw when steadily providing the maximum output. For example, in the image above, you can see that the manufacturer specifies a 12.2 Amps compressor’s RLA.

FLA stands for Full Load Amps, and in this case, refers to the maximum amount of current that the air conditioner’s fan uses when providing the maximum output. For example, in the image above, you can see that the manufacturer specifies 3.4 Amps as the fan motor FLA.

Now, both the compressor and the fan draw current when the RV AC is running. Therefore, the amount of current, in Amps, that the RV AC may potentially require during normal operation can be calculated as follows:

Potential Running Amps = Compressor’s RLA (Amps) + Fan Motor’s FLA (Amps)

In our particular example, the potential amp draw of the air conditioner is:

Potential Running Amps = Compressor’s RLA (Amps) + Fan Motor’s FLA (Amps)

Potential Running Amps = 12.2 Amps + 3.4 Amps

Potential Running Amps = 15.6 Amps

Now that we know the amperage of the air conditioner (15.6 Amps) and the manufacturer specifies 115 Volts and the Voltage of the unit, we can calculate the potential running watts of the RV AC:

Potential Running Watts = Potential Running Amps x Voltage

Potential Running Watts = 15.6 Amps x 115 Volts

Potential Running Watts = 1794 Watts

According to these calculations, the air conditioner in our example should at most use 1794 Watts of power under full load.

5000 BTU Window Air Conditioners

Now, what we’ve just calculated is the “continuous” power usage of the unit, which is the amount of power it uses in its steady state of operation.

However, as previously mentioned, when the unit is initially turned on, it will require a much greater amount of power to initiate.

This amount of power that the RV AC uses when starting up can also be calculated using the Voltage rating of the unit (115 Volts) and the Surge Current specified by the manufacturer:

For example, if you take a second look at the nameplate of this AC unit, you can see that the manufacturer specifies “Compressor’s LRA” of 63 Amps.

LRA stands for “Locked Rotor Amps”, and it indicates the potential amount of current that the motor within the compressor might require to overcome its static state and gain momentum.

When you turn on the AC, the fan typically starts running first, and in a few seconds, the compressor kicks in. Therefore, the potential amp draw of the AC unit during startup can be calculated as follows:

Potential Starting Amps = Compressor’s LRA (Amps) + Fan Motor’s FLA (Amps)

Potential Starting Amps = 63 Amps + 3.4 Amps

Potential Starting Amps = 66.4 Amps

As a result, the potential starting wattage of this unit is:

Potential Starting Watts = Potential Starting Amps x Voltage

Potential Starting Watts = 66.4 Amps x 115 Volts

Potential Starting Watts = 7636 Watts

According to the specifications of this air conditioner, the unit could potentially require up to 7636 Watts (7.6 kW) of power to start up.

Now, it is important to note that this starting wattage is not typical, and represents a maximum, or a worst-case scenario. However, when sizing equipment that should be able to operate the RV AC, such as an inverter or a generator, this “potential” starting wattage should be taken into consideration.

Read more about this here:

Now, as explained at the beginning of this article, the power usage (Watts) of the air conditioner is only one aspect of its electricity usage. An even more important aspect is the Energy Consumption of the unit, especially if you’re planning on running the RV AC on solar or on batteries.

This brings us to the next section.

Mini-Split Air Conditioners

## How much energy does an RV air conditioner use?

As mentioned above, the amount of energy that your RV AC consumes will mainly depend on the power it draws when it’s running, as well as the unit’s usage duration.

However, just like any air conditioner, the energy consumption of an RV air conditioner will also depend on other factors, such as:

• The outdoor temperature
• The indoor temperature setpoint
• The quality of the RV’s insulation
• The efficiency of the unit

Be that as it may, as a rule of thumb, the average RV air conditioner will generally consume between 0.8 and 1.3 kWh of energy per hour. For example, if you leave your RV’s air conditioner for 6 hours a day, the AC unit should consume between 5 and 8 kWh of energy per day.

To provide some more perspective, the following table estimates the energy consumption of RV air conditioners of different BTU ratings:

The estimates provided in the table above should give you a good understanding of your RV air conditioner’s hourly energy consumption. This information can be combined with your daily usage patterns to calculate the daily or even monthly energy usage of the AC:

Daily Energy Usage (kWh/day) = Hourly Energy Usage (kWh/hour) x Daily Usage (hours/day)

For instance, a 15,000 BTU RV AC typically consumes about 0.9 to 1.3 kWh (kiloWatt-hours) of energy per hour of operation. If you assume it runs for 8 hours each day, this would translate to approximately 7 – 10 kWh of energy consumption daily.

If your RV has two ACs running simultaneously, it will naturally consume twice that amount of energy.

Now, if you’re interested in running your RV air conditioner using solar panels and batteries, I’ve prepared detailed posts on the subject. Here are the links:

If you plan to operate your RV AC with a generator, you may want to refer to this article to learn more about fuel consumption.

If your goal is simply to determine the costs associated with running your AC while connected to the grid, please continue reading.

5000 BTU Window Air Conditioners

## How much does it cost to run an RV air conditioner?

The cost of running your RV air conditioner mainly depends on how much energy it consumes. This, in turn, is influenced by the AC unit’s cooling capacity and various operating factors like temperature, humidity, how long you use it each day, and how efficient it is.

Additionally, the final cost will vary depending on the electricity rates in the area.

As a general rule of thumb, RV air conditioners with ratings of 13,500/15,000 BTUs usually use about 1 to 1.2 kWh (kilowatt-hours) of energy for every hour they run. Considering the average cost of electricity in the United States, which is roughly 16 cents per kWh, this would mean an hourly cost of around 16 – 19 cents.

Assuming the same energy usage per hour, electricity cost, and an 8-hour daily operation, you can expect your RV air conditioner to cost approximately \$1.4 per day or \$42 per month to operate.

For a clearer view, here’s a table estimating the hourly operating cost of RV air conditioners based on their BTU rating:

The cost estimates provided in the table are based on the typical hourly energy consumption of these RV ACs, combined with the U.S. national average cost per kWh of about \$0.16/kWh.

However, it’s vital to highlight that, aside from your RV AC’s energy use, the actual operating cost can vary significantly based on the local electricity rates. The real cost per kWh can fall anywhere between 10 to 30 cents (\$0.1 to \$0.3).

However, it is important to emphasize that, aside from your RV AC’s energy use, the actual operating cost can vary significantly based on the local electricity rates. Depending on the area, the actual cost per kWh can range from 10 to 30 cents a kWh (\$0.1 to \$0.3).

Let’s take a practical example. Suppose you have a 15000 BTU RV air conditioner that typically consumes 1.2 kWh of energy per hour, and that you run it for 8 hours each day.

To find the daily energy usage:

Daily Energy Consumption (kWh/day) = Average Hourly Energy Consumption (kWh/hour) x Daily Usage Duration (hours/day)

Daily Energy Consumption (kWh/day) = 1.2 kWh/hour x 8 hours/day

Daily Energy Consumption (kWh/day) = 9.6 kWh/day

Now, let’s assume your RV is hooked up somewhere in Texas, where the average cost per kWh, according to the Energy Information Administration (EIA), is about 14.2 cents (\$0.142) per kWh.

With these assumptions in mind, the daily cost of running the air conditioner can be calculated as follows:

Daily Cost (\$/day) = Daily Energy Consumption (kWh/day) x Cost per kWh (\$/kWh)

Daily Cost (\$/day) = 9.6 kWh/day x \$0.142/kWh

Daily Cost (\$/day) = \$1.36 per day

For the monthly cost:

Monthly Cost (\$/month) = Daily Cost (\$/day) x 30 (days/month)

Monthly Cost (\$/month) = \$1.36/day x 30

Monthly Cost (\$/month) = \$40.8 per month

To save you time, I’ve created a calculator that can estimate the daily and monthly costs of running your RV air conditioner based on its BTU rating, daily usage hours, and location:

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##### Younes Anas EL IDRISSI

Younes Anas EL IDRISSI is the founder of RenewableWise.com and the driving force behind it. As a former Electrical Engineer and an energy self-sufficiency enthusiast, Younes' mission is to leverage his expertise and experience to simplify the complexities of solar energy and make it easily understandable for anyone looking into DIY energy solutions. Learn more about Younes and the story of RenewableWise here.

### 2 Comments

1. Hi Younes, Can you answer a question. I would like to run my a/c in my 5th wheel while going down the road. (I do not have an onboard generator). Can the truck alternator provide enough amps to keep the 5th wheel batteries charged and running the a/c. If I understand what I am asking, it is DC (alternator) to DC (batteries) to inverter AC to run the a/c How do you accomplish this. Thanks Bob.

• Hey there Bob,

The amps that the alternator produces might be enough to run the AC if you’re driving at highway speed. However, I don’t think the alternator alone is enough to run the AC for a long time, as air conditioners use a relatively high amount of energy.
At some point, the batteries will be depleted and will have to be recharged externally.
Hope this helps.