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RV AC Power: How Many Watts To Run An Rv Air Conditioner
How many watts does it take to run an RV air conditioner? Simply put, it depends on the size of your unit and whether it’s just starting up or running steadily. A typical RV air conditioner uses about 1500 to 3500 watts during its initial startup phase and then settles down to use roughly 600 to 1500 watts while continuously running. This difference between starting power and running power is very important for anyone using RV AC power, especially when considering things like RV air conditioner power consumption and what power sources you can use. Knowing the RV AC wattage requirements helps you stay cool without tripping breakers or running out of power.
Knowing Your RV AC Power Use
Living comfortably in your RV often means staying cool when the weather is hot. But running an air conditioner takes power. A lot of power, compared to other things in your RV. If you’re plugged into shore power at a campground, this might not be a big concern, as long as you know your amperage limit (like 30 amp or 50 amp service). But if you plan to run your AC using a generator, batteries, or an inverter, knowing the RV AC power draw is absolutely crucial. You need to know exactly what the unit demands to avoid problems.
Two main things you need to look at are watts and amps. Watts tell you the total amount of power something uses. Amps tell you the amount of electrical current flowing. Both are important for figuring out what your power source needs to handle. When people ask about RV air conditioner power consumption, they usually want to know the watts it uses, as watts are often used to size generators and inverters. The amperage for RV air conditioner units tells you how much current is needed, which is vital for choosing the right gauge of wire or knowing if your breaker can handle the load.
Decoding Watts and Amps
Let’s take a moment to get a clearer picture of watts and amps in the context of RV ACs. Think of electricity like water flowing through a pipe.
* Volts (Voltage): This is like the water pressure. In most RVs and homes in North America, the AC power voltage is around 120 volts. This pressure stays pretty constant.
* Amps (Amperage): This is like the rate of water flow – how much water is moving through the pipe at any given moment. Appliances like your RV AC draw a certain number of amps when they are running.
* Watts (Wattage): This is like the total power of the water flow, combining pressure and flow rate. It’s the work the electricity can do. The simple relationship is: Watts = Volts x Amps.
So, if an RV AC uses 10 amps at 120 volts, it uses 10 x 120 = 1200 watts. This simple formula helps you switch between amps and watts if you only know one value. Most manufacturers list both the running amps/watts and sometimes the starting amps/watts for their RV AC units. Checking the label on your AC unit or its manual is the best way to find its exact specifications.
Starting Power vs. Running Power: The Big Difference
Here’s where many people get confused, especially when picking a generator. An electric motor, like the one in your RV air conditioner’s compressor, needs a much bigger burst of power to start up than it does to keep running. This is called the “startup surge” or “inrush current.”
- RV AC Starting Amps: This is the high amount of current the AC pulls for a very short time (just a second or two) when the compressor kicks on. This can be 2 to 3 times higher, or even more, than the running amps. If your power source (like a generator or inverter) cannot handle this brief surge, it will likely shut down, trip a breaker, or the AC simply won’t start. This is why knowing the RV AC starting amps is critical for generator and inverter sizing.
- RV AC Running Amps: This is the lower, continuous amount of current the AC uses once the compressor is running smoothly. This is the power level it maintains for most of the time it is cooling. The RV AC running amps determine the continuous load on your power source.
Let’s look at some common examples to illustrate this.
Looking at Watts for Common RV AC Sizes
RV air conditioners are often rated by their cooling capacity in BTUs (British Thermal Units). The most common sizes are 13,500 BTU and 15,000 BTU. Larger units generally use more power.
Watts for 13500 BTU RV AC
A 13,500 BTU RV air conditioner is a very common size for many RVs.
* Typical Running Watts: About 1200 to 1500 watts.
* Typical Running Amps: About 10 to 12.5 amps at 120V (Watts / Volts = Amps -> 1200/120=10, 1500/120=12.5).
* Typical Starting Watts: Can be 2500 to 3500+ watts for a moment.
* Typical Starting Amps: Can be 20 to 30+ amps at 120V (2500/120 ≈ 20.8, 3500/120 ≈ 29.2).
So, if you’re asking about watts for 13500 BTU RV AC, you’re looking at around 1200-1500 watts running, but you need a power source that can handle a brief surge much higher than that, potentially over 3000 watts.
Watts for 15000 BTU RV AC
A 15,000 BTU RV air conditioner is a larger, more powerful unit, often found in bigger RVs or used where more cooling is needed.
* Typical Running Watts: About 1400 to 1700 watts.
* Typical Running Amps: About 11.5 to 14 amps at 120V (1400/120 ≈ 11.7, 1700/120 ≈ 14.2).
* Typical Starting Watts: Can be 2800 to 4000+ watts for a moment.
* Typical Starting Amps: Can be 23 to 33+ amps at 120V (2800/120 ≈ 23.3, 4000/120 ≈ 33.3).
For watts for 15000 BTU RV AC, the running wattage is a bit higher than the 13,500 BTU unit, typically 1400-1700 watts. But again, the startup surge is significant, potentially needing over 4000 watts from your power source for a second or two.
Here’s a simple table summarizing typical values:
Typical RV AC Power Consumption (Approximate)
| AC Size (BTU) | Running Watts | Running Amps (at 120V) | Starting Watts (Surge) | Starting Amps (Surge) |
|---|---|---|---|---|
| 13,500 | 1200 – 1500 | 10 – 12.5 | 2500 – 3500+ | 20 – 30+ |
| 15,000 | 1400 – 1700 | 11.5 – 14 | 2800 – 4000+ | 23 – 33+ |
Note: These are typical ranges. Always check the specific unit’s label or manual for exact numbers.
These numbers highlight why the RV AC wattage requirements and RV AC starting amps are so important, especially for off-grid power solutions like generators.
Picking the Right Generator for Your RV AC
If you want to run your RV air conditioner when you’re not plugged into shore power, you’ll likely need a generator. Choosing the right size generator is crucial, and it’s where knowing the RV AC starting amps and RV AC running amps really pays off. The most important number for generator sizing is the peak or starting wattage the generator can provide, not just its continuous running wattage.
Generator Wattage for RV Air Conditioner Use
Generators are typically rated with two wattage numbers:
1. Running Watts (Continuous Watts): The power the generator can provide constantly over a long period.
2. Starting Watts (Peak Watts): The extra burst of power the generator can provide for a few seconds to start motors. This is the number you need to pay close attention to for your RV AC.
To figure out the generator size needed for RV AC, you need a generator whose starting watts are higher than the RV AC’s starting watts (surge). Also, the generator’s running watts must be higher than the RV AC’s running watts plus the running watts of any other appliances you plan to run at the same time (like the microwave, lights, or converter charging batteries).
Sizing a Generator for a Single RV AC
For a single 13,500 BTU RV AC:
* Needs about 1200-1500 running watts.
* Needs about 2500-3500+ starting watts.
You would typically need a generator that provides at least 2800 to 3500 starting watts and around 2000-2500 running watts to comfortably start and run this AC, plus maybe a few other small items. A common choice might be a 3000 or 3500-watt inverter generator.
For a single 15,000 BTU RV AC:
* Needs about 1400-1700 running watts.
* Needs about 2800-4000+ starting watts.
You would likely need a generator with at least 3000 to 4000 starting watts and around 2200-2800 running watts. Again, a 3500 or 4000-watt inverter generator is often needed here. Some larger 15k BTU units or older, less efficient ones might even push you towards a 4000+ watt generator.
Sizing a Generator for Multiple RV ACs
If your RV has two air conditioners, running both at the same time requires a much larger generator. You need to add the running watts of both units and ensure the generator can handle the combined running load. The starting load is a bit more complex, as it depends on whether the units cycle on at the exact same second (unlikely) or if they start a few seconds apart. Good power management systems in RVs will often delay the startup of the second AC to avoid massive surges.
For two 13,500 BTU RV ACs:
* Combined Running Watts: ~2400 – 3000 watts.
* Combined Starting Watts: This is tricky. If they start separately, the peak surge might be the highest single surge plus the running load of the other unit. Say one needs 3500W start and the other runs at 1500W, you need ~5000W surge capacity. If they somehow started simultaneously, it would be much higher.
For two 15,000 BTU RV ACs:
* Combined Running Watts: ~2800 – 3400 watts.
* Combined Starting Watts: Similar logic as above, potentially needing a higher surge capacity.
To run two RV ACs, you are generally looking at generators in the 5000 to 6500+ running watt range, with correspondingly higher starting watts. This is why many RVers with two ACs opt for larger built-in generators or link two smaller inverter generators together if they need to run both ACs off-grid. The generator wattage for RV air conditioner use, especially for two units, needs to be substantial.
Inverter vs. Conventional Generators
When looking at generators for your RV AC, you’ll mainly see two types:
1. Conventional Generators: These are typically louder, heavier, and the power they produce might not be as “clean” (stable voltage and frequency). They are often less expensive for the wattage they produce.
2. Inverter Generators: These are generally quieter, lighter, more fuel-efficient, and produce very “clean” power, which is safer for sensitive electronics like those found in RV appliances. They often have a higher starting wattage capacity relative to their running wattage compared to conventional generators.
For running sensitive electronics like your RV’s air conditioner and other appliances, an inverter generator is usually the preferred choice due to the clean power and quieter operation. They are well-suited to handle the RV AC starting amps without issues.
Battling the Startup Surge: Soft Starters
The large RV AC starting amps needed for the compressor to kick on are the main hurdle when using smaller generators, inverters, or even 30 amp shore power service where you want to run other appliances. A clever solution to this problem is installing a “soft starter” (like a Micro-Air EasyStart or similar product).
Deciphering How Soft Starters Work
A soft starter is a device installed directly onto your RV air conditioner’s compressor. Instead of sending a massive jolt of power to the compressor all at once, the soft starter gradually ramps up the power over a few seconds.
This smooth ramp-up drastically reduces the RV AC starting amps (and thus starting watts). A soft starter can reduce the startup surge by 60-70% or even more.
Benefits of Using a Soft Starter
- Run AC on Smaller Generators: You might be able to run a 13,500 BTU or even a 15,000 BTU AC on a 2000-watt inverter generator, which is much lighter and quieter than the 3000-4000 watt generators typically needed.
- Run AC on 30 Amp Shore Power More Easily: With a soft starter, you can often run your AC plus other appliances (like the microwave or coffee maker) on a standard 30 amp hookup without tripping the main breaker.
- Run AC on Inverter/Battery Systems: Makes it much more feasible to power your AC from your RV’s battery bank through a sufficiently sized inverter, opening up possibilities for off-grid cooling without a generator running constantly.
- Less Stress on the AC Unit and Power Source: The smoother startup is easier on the compressor and your electrical system.
While installing a soft starter is an extra cost, for many RVers who want more flexibility in their power options, it’s a worthwhile investment. It fundamentally changes the RV AC power consumption dynamics during startup.
Shore Power Considerations
When you’re plugged into shore power at a campground, the power source is the campground’s electrical system. The limitation here is the amperage rating of the hookup you have. Common RV hookups are 30 amp and 50 amp.
- 30 Amp Service: Provides a total of 30 amps at 120V, which is 30 x 120 = 3600 watts total available power. This is often enough to run one RV AC (remembering its running amps are typically 10-14), but running a second AC or multiple high-draw appliances simultaneously can easily exceed 30 amps and trip the main breaker. This is where a soft starter on your AC can be a big help on a 30 amp site.
- 50 Amp Service: Provides two separate 50 amp lines at 120V. This is sometimes misunderstood; it’s not 100 amps total, but essentially gives you access to much more power. It’s effectively two 120V/50A feeds. The total available power is much higher, easily allowing you to run two or even three ACs, plus other appliances, at the same time.
Knowing the amperage for RV air conditioner units (both starting and running) and comparing it to your shore power limit is important to avoid nuisance trips.
Other Factors Affecting RV AC Power Draw
While the BTU size gives you a baseline for RV air conditioner power consumption, other things can influence how much power your unit uses:
- Outside Temperature and Humidity: On hotter, more humid days, the AC has to work harder and run longer, increasing overall energy use. The running watts might also increase slightly as the compressor is under more load.
- RV Insulation: A well-insulated RV keeps cool air in and hot air out better, meaning the AC cycles on and off less frequently. Poor insulation means the AC runs almost constantly, leading to higher overall power consumption.
- Setting Temperature: Setting the thermostat to a very low temperature will make the AC run longer. A more moderate setting will reduce run time.
- Filter Cleanliness: A dirty air filter restricts airflow, making the AC work harder to cool the space. This can increase power draw and reduce efficiency. Regularly cleaning or replacing the filter is a simple energy-saving step.
- Age and Condition of the Unit: Older or poorly maintained AC units might be less efficient and use more power to achieve the same cooling as a newer unit.
- Direct Sunlight: Parking your RV in direct sunlight, especially on the roof where the AC unit is, can significantly increase the cooling load and how hard your AC has to work. Parking in the shade helps a lot.
All these factors influence the total RV AC power draw over time, even if the peak wattage and amperage ratings of the unit remain the same.
Tips for Reducing RV AC Power Consumption
Since the AC is often the biggest power hog in an RV, especially when using limited power sources like generators or batteries, finding ways to reduce its power consumption can make a big difference.
- Park in the Shade: This is probably the most effective tip. Keeping direct sunlight off your RV reduces heat gain significantly.
- Improve Insulation: Add insulation where possible, especially around vents, windows, and roof hatches. Reflective window coverings also help block heat.
- Use Vent Fans: Before turning on the AC, use your ceiling vent fans to push out hot air from inside the RV. This helps cool down the interior quickly.
- Set a Moderate Temperature: Don’t try to make your RV arctic cold. Setting the thermostat to a comfortable but not extreme temperature (e.g., 75°F or 24°C) reduces run time.
- Use Dehumidify Mode (if available): High humidity makes heat feel worse. Some ACs have a dry mode that focuses on removing moisture with less cooling, which can make a slightly warmer temperature feel more comfortable and use less power than blasting cold air.
- Keep Filters Clean: Clean or replace your AC filters regularly (check your manual for how often). This ensures efficient operation.
- Check Seals and Vents: Make sure all windows, doors, and vents are properly sealed to prevent cold air leaks. Close off areas you aren’t using if possible.
- Pre-cool Your RV: If you’re leaving a cooler climate or have been driving, open windows and vents to let the hot air escape before starting the AC. If you know you’ll be arriving at a hot campground later, consider starting the generator and AC before you’re fully set up (if rules allow) to get a head start on cooling.
- Consider a Soft Starter: As discussed, this is an upfront investment but can dramatically reduce the needed starting wattage, offering more flexibility in power options.
By implementing these tips, you can reduce the overall demand on your power system and make it easier to manage your RV AC power consumption.
Final Thoughts on RV AC Power
Running an RV air conditioner requires a significant amount of power, particularly during startup. Knowing the typical RV AC wattage requirements for both running and starting is essential, whether you’re relying on shore power, a generator, or an inverter system. The RV AC starting amps are often the limiting factor for smaller power sources.
A 13,500 BTU unit typically needs around 1200-1500 running watts and 2500-3500+ starting watts. A 15,000 BTU unit needs about 1400-1700 running watts and 2800-4000+ starting watts. This translates directly to the generator size needed for RV AC use. You generally need a generator with a peak (starting) wattage rating higher than your AC’s surge requirement and a running wattage rating higher than your AC’s continuous need plus any other loads.
Investing in an inverter generator provides cleaner power and quieter operation. For those looking to use smaller generators or have more flexibility on 30 amp shore power or battery systems, installing a soft starter to reduce the RV AC starting amps is a highly effective solution.
Managing your RV AC power draw also involves simple practices like parking in the shade, maintaining your unit, and improving your RV’s insulation. By understanding the power demands and using smart strategies, you can stay cool and comfortable in your RV without power headaches. The generator wattage for RV air conditioner operation, along with other factors, determines how much power capability you need.
Frequently Asked Questions (FAQ)
What is the difference between running watts and starting watts?
Running watts are the power an appliance uses continuously. Starting watts are a brief, much higher burst of power needed just to get an electric motor (like the one in your AC compressor) spinning. Generators are rated for both, and the starting watts capacity is key for AC units.
Can I run my RV AC on a 2000-watt generator?
Typically, a standard 13,500 or 15,000 BTU RV AC unit’s starting surge is too high for a 2000-watt generator. However, if you install a soft starter on your AC, you can often reduce the starting surge enough to run the AC on a 2000-watt inverter generator. Without a soft starter, you usually need at least a 2800-3500 watt generator.
How many amps does a 13,500 BTU RV AC use?
A 13,500 BTU RV AC typically uses around 10 to 12.5 running amps and 20 to 30+ starting amps.
How many amps does a 15,000 BTU RV AC use?
A 15,000 BTU RV AC typically uses around 11.5 to 14 running amps and 23 to 33+ starting amps.
Can I run two RV ACs on a 30 amp shore power connection?
Generally, no. A 30 amp service provides about 3600 watts total. Two standard RV ACs running simultaneously can easily draw 2400-3400 running watts or more, leaving little capacity for other appliances. Starting surges can also trip the breaker. 50 amp service is designed to handle two ACs.
Do RV ACs use 12 volt or 120 volt power?
RV air conditioners use 120-volt AC (alternating current) power, just like most household appliances. Your RV’s 12-volt system powers things like lights, fans, and pumps, but not the main AC unit.
How can I find the exact power requirements for my specific RV AC unit?
Look for a label on the AC unit itself (often under the cover on the roof or inside the return air grille) or check the owner’s manual for your RV or the specific AC unit model. This label will list the voltage, frequency, and typically the running amps and sometimes the LRA (Locked Rotor Amps, which is a measure related to the maximum starting amp draw).
What is LRA on an AC unit?
LRA stands for Locked Rotor Amps. It’s the maximum current drawn by the motor when it’s trying to start but can’t spin (like when it first kicks on). It’s an indicator of the maximum possible starting surge, though the actual surge duration is very short. Generator starting wattage needs to be sufficient to overcome this initial demand.