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How Many Watts Does a Camper AC Use? A Complete Breakdown

A Comprehensive Guide

RV life is all fun and adventure until the summer heat turns your camper into an oven. You run to turn on the AC, but suddenly, you’re hit with panic. Will my generator handle it? What if my battery drains and the AC shuts down in the middle of the night?

Understanding your AC power needs is essential. Since it will make all the difference between a relaxing camping experience and a sweaty disaster.

Let us guide you on how many watts your camper AC uses and how to reduce its power usage.

What are RV AC Wattage and BTU?

BTU (British Thermal Units) measures the cooling capacity of the AC unit. It determines how much heat the unit can remove from a place per hour. Higher BTU means your AC can cool a larger area or cool it more quickly.

Wattage is like the fuel your AC needs to work. It determines how much energy your AC uses to run. Higher wattage means more electricity your AC will use.

It’s something like this:

Higher BTU = Higher cooling capacity

High wattage = High electricity consumption

In short, BTU tells you how much your AC can cool, and wattage tells you how much power it needs to do that.

BTU and wattage help you decide which generator you should buy. And if you’re camping off-grid, understanding your power needs will protect you from facing power failures in the middle of the night.

How Many Watts Does a Camper AC Use?

Camper AC units use between 1,200 and 3,500 watts, depending on their size, brand, and efficiency. Here’s a complete breakdown of the startup and running wattages of camper ACs.

The power usage of your camper AC depends on its BTU ratings, but other factors also influence how much power your AC uses.

Hot weather makes your AC work harder and results in high power consumption. Insulation also plays a key role; poorly insulated panels lose cool air quickly.

The efficiency of your AC unit is measured by the EER (Energy Efficiency Ratio), which determines how much cooling it provides per watt of electricity. A higher EER means more cooling for less power. If you're buying an energy-efficient AC, look for a unit with an EER of 10 or higher.

Additionally, humidity level, size of your RV, age of the AC unit, and number of people inside it affect the overall cooling capacity of the air conditioner. Understanding these factors will assist you in choosing the right AC for your camper.

NOTE: All the values mentioned in the table are approximate, as the startup and running wattage depend on the model and efficiency of your AC.

What is the Difference Between Startup and Running Wattage?

The difference between startup and running wattage is like the difference between pushing a car to start moving versus keeping it rolling once it's already in motion.

Starting wattage (surge wattage) is the initial extra power that the AC needs to start working. It is usually two or three times more than the running wattage. Surge wattage can vary depending on the AC’s compressor type and whether a soft device is installed.

Running wattage is the power your AC needs to keep running once it’s on. For example, a 13,500 BTU RV air conditioner typically requires 1,200–1,500 watts to run continuously but needs around 2,750–3,500 watts of surge wattage.

If your generator only matches the running wattage, your AC will not start unless your generator’s power matches the startup wattage.

How to Calculate Your Camper AC’s Wattage?

If you don’t know your AC’s wattage, you can find it by checking the label on the unit or referring to the owner's manual. Look for the Voltage (V) and Amperage (A), as these values will help you calculate the wattage.

Sometimes, Wattage (W) is also mentioned on the nameplate or owner’s manual. But if you can’t find any wattage, use the simple formula:

Watts = Volts × Amp

For example, if your AC unit runs on 120V and draws 12 amperes, then the running wattage will be
Running wattage =120 × 12 = 1440W
However, the starting wattage is 2 to 3 times higher than the running wattage. To estimate surge wattage, multiply running wattage by 2 or 3, depending on your AC model and compressor type.

For a more accurate measurement, you can also use a Wattage meter to measure the consumption power of your AC.

Energy-Efficient Tips to Reduce Your AC Power Usage

By following certain energy-efficient practices, you can reduce your AC power usage. Try these guidelines while using your RV AC.

1. Insulate Your RV Doors and Windows

Properly insulate your RV doors and windows to prevent incoming heat during the summer. For this purpose, thermal curtains or reflective window covers should be used to keep hot air out and cool air in. You should also use insulated wall panels for better heat control.
You can try another hack to insulate your campervan properly. Buy a thermal camera, which will allow you to locate any hot spots in the RV walls. This way, you can do better insulation around those places that are actually hot.

At My Custom Van, we offer custom campervans with a fully insulated ceiling, camper walls, rear doors, and windows. You can also buy ceiling panels and insulated van windows from our Vankea store.

2.Use Fans for Air Circulation

Use ceiling fans or portable fans to circulate air throughout the room. Fans distribute cool air evenly and reduce the need to run your AC constantly. Moreover, fans use much less power than ACs.

3.Keep Your AC Filter Clean

A dirty filter can reduce the efficiency of your AC. Therefore, regularly clean your AC filter for better airflow.

4.Use Energy-Efficient AC for Your Campervan

One of the most effective ways to reduce power consumption in your camper is to use an energy-efficient AC. These ACs are environment-friendly, have proper BTU ratings, inverter technology, and lower starting wattage.
Efficient ACs cool down a place by using less power. It’s the best option for RV owners who rely on small generators, solar panels, and batteries.

5.Use a Soft Start Device

An AC uses more power at the start when it’s turned on. RV AC’s startup wattage is usually 2-3 times more than the running wattage, which can overload small generators.

To reduce this initial high surge wattage, install a soft start device.
This device reduces the starting wattage, making it possible for you to run your camper AC on small generators and solar panels.

6.Optimize Thermostat Setting

Moderate thermostat settings can help you cut down your RV AC's power consumption and maximize the AC’s efficiency. Set your thermostat to 75°F- 78°F for comfort and save power.

Avoid setting your AC too low; it can also increase power consumption. Turn on “auto” mode on your AC instead of “on.” It will turn on and off the AC cycles according to the temperature, saving power.

7.Park Your Camper Under the Shade

Direct sunlight heats the interior of your camper quickly, making the AC work harder and use more power to keep things cool.

Always park your camper under trees, buildings, etc. You can also use an RV awning to block direct sunlight. Make sure to park your camper's larger window away from the sun.

Maintenance Practices for Your Camper AC

Elevator beds are the hallmark of our interior designs and most of our models at My Custom Van feature elevator beds. Elevator beds, as the name suggests, are related to automation.

It is a bed that moves up and down just like an elevator. When not in use, it frees up floor space underneath, which can be used for dinettes, seating, or storage.

Dirt accumulation in your AC filter can reduce cool airflow. It will lead AC to work harder to keep your place cool. Therefore, clean your AC filter every 1-2 months.

Remove the filter from your AC.

Replace the disposable filter if it is damaged and dirty.

Clean the washable filter with a mild soap and water, and dry it completely.

1.Clean Your AC Filter

How to Do It:

Dust and debris buildup in coils can lead to lower AC efficiency. Check the evaporator and condenser coils at least once a year.

Turn off the power to the AC.

Use a soft brush to remove the dirt.

You can also use coil cleaner spray for deeper cleaning.

Remove the AC cover

2.Clean the Evaporator and Condenser Coils

How to Do It:

A clogged drain line in your AC can cause a water leak. Try to check it once a year.

Locate the drain line (a small tube near the AC unit).

Pour a mixture of water and vinegar through the pipe to avoid mold buildup.

Use a pipe cleaner to clear any clogs.

3.Inspect the Drain Line

How to Do It:

Worn-out fans or motors can create strange noises and affect the cooling of your AC. Check fans or motors every year.

Turn off the power.

Tighten any loose fan blades.

Lubricate the motor bearings if this is mentioned in the manual.

Remove the cover of the AC and clean the dirt with a soft brush.

4.Inspect the Fan and Motor for Proper Operation

How to Do It:

A faulty thermostat can lead to less cooling and high energy usage. Check it properly once a year.

Test the thermostat by setting it to different temperatures.

Make sure that it is calibrated correctly and reads the right temperature.

5.Test the Thermostat

How to Do It:

How to Choose the Best Generator for Your Camper AC?

Understanding how many watts your camper AC uses is only half the question; you also need a generator that can handle both the starting and running wattage.

There is a step-by-step guide for you to follow before buying a generator for your camper.

First, learn about the starting and running wattage of your camper AC. You can find it on the AC’s nameplate or in the owner’s manual.
Now, choose a generator whose rated wattage is greater than your AC’s startup wattage. For example, if your AC has 3,500 starting watts, pick a generator with more than 4,000 watts.
If you have other appliances such as a fridge, oven, or light, add up the wattages of all these devices. Then, choose a generator that can handle the total wattage of these running devices.
Select which generator you want to use, an inverter or a conventional generator. Inverter generators are fuel-efficient and quieter but are expensive. Conventional generators are budget-friendly but use more fuel and create noise. Select a generator that suits your needs.

Popular Generator Sizes for Camper AC

Popular generator sizes for camper ACs are the following:

2,000-3,000 Watts: Best for small AC units (5,000-10,000 BTU)

3,500-4,000 Watts: Ideal for medium AC units (13,500 BTU)

5,000 Watts: Suitable for large AC units (15,000 BTU)

Can You Power a Camper AC with a Portable Power Station?

If you love boondocking or want to use your camper's AC for a short time, you can use a portable power station.
Portable power stations are:

Quiet
Eco-friendly
Relying on solar panels for charging
Require little or no maintenance

You should know the startup and running wattage to power your camper AC with a portable power station.

Then, choose a power station with a high wattage output and watt-hours (wattage output greater than your AC surge wattage). You should also use a soft start device to reduce the starting wattage.

Some limitations of Portable power stations are:

Less portable (Especially those with high wattage)
Not suitable if you want to run your AC for long hours or overnight.
Highly expensive

Can You Run a Camper AC on Solar Power?

Yes, you can run a camper AC on solar power. ACs consume a lot of energy, and that’s why a complete setup is required to run your AC on solar power.

Things you need to run a camper AC on solar power are the following:

A high-capacity battery (Lithium or LiFePO4) is required for this purpose. For example, a 13,500 BTU AC needs about 12,00 to 15,00W per hour while running.

A 200Ah lithium battery can run your AC for approximately 1 to 1.5 hours. If you want to run the AC overnight, you’ll need at least 400-600Ah, and for a full 8-hour runtime, 800Ah or more is recommended.

On a sunny day, a 400W solar panel can generate around 1,200 to 1,400 watt-hours (Wh) per day, depending on location, sunlight duration, and panel efficiency.

You will need 1,800- 3,000W solar panels if you want to power an AC.

A soft start device to cut the initial surge power is also highly recommended.

How long you can run your camper's AC on solar panels depends on your battery capacity and solar panel output. A basic setup (4,00W solar, 200Ah battery) can only run your AC for 1-2 hours. You need an advanced setup to run AC for 8+ hours.

Solar AC is the best option for you if:

You are an eco-conscious person.
You’re an off-grid traveler.
You want AC for a short period.

Solar AC is not a good option for full-time RVers because:

Not practical for 24/7 cooling unless you have a powerful solar system and a battery
Expensive
Weather-dependent (low sun-low power)

The next thing to consider is your van size and layout. We recommend pull-out, fold-away, or dinette-to-bed options for small vans. If you are traveling in a medium- to large-sized van, stationary beds or elevator beds will perfectly suit your needs.