For American RV owners, understanding RV air conditioner watt usage is crucial for trip planning, generator sizing, and energy efficiency. Whether hooked up at a campground, boondocking, or relying on solar power, the right knowledge ensures cool comfort without unexpected power issues. This comprehensive guide breaks down RV AC wattage, factors affecting power draw, running multiple appliances, and practical tips for managing your RV’s energy needs.
| Type of RV AC | Typical Starting Watts | Typical Running Watts |
|---|---|---|
| 13,500 BTU Roof AC | 2,750–3,000 W | 1,200–1,600 W |
| 15,000 BTU Roof AC | 3,200–3,500 W | 1,500–2,000 W |
| Portable RV AC | 1,500–2,000 W | 900–1,300 W |
| AC with Soft Start | 1,600–2,000 W | 1,200–1,600 W |
What Determines RV Air Conditioner Watt Usage?
An RV air conditioner’s watt consumption depends on several variables. The most significant factors are compressor size (BTUs), design efficiency, ambient temperature, the condition of the AC unit, and how you power your RV. Understanding these elements helps you choose the right generator, optimize fuel use, and manage campsite electrical loads.
- Compressor Size/BTUs: Higher BTUs mean more power draw, especially during startup.
- Startup vs. Running Watts: AC units require a surge of electricity to start, often double the running wattage.
- Climate and Humidity: Hotter and more humid days cause ACs to run longer and harder, increasing wattage demand.
- Age and Maintenance: Dirty coils or old parts make ACs less efficient, raising energy use.
- Shore Power Vs. Generator: Available power sources may limit how many appliances run alongside your air conditioner.
Average Wattage For Popular RV Air Conditioner Sizes
RV air conditioners come in common sizes categorized by BTUs, which directly influence wattage. The most popular models are 13,500 and 15,000 BTUs, but smaller or portable units are available for compact RVs.
13,500 BTU RV AC
This size is standard for many travel trailers and small motorhomes. Expect starting watts between 2,750 and 3,000 and running watts around 1,200 to 1,600. Older units on hot days may use more.
15,000 BTU RV AC
Larger fifth wheels and Class A motorhomes often use these for added cooling capacity. These ACs can require 3,200 to 3,500 watts to start and up to 2,000 watts to run continuously.
Small And Portable RV AC Units
Compact rooftop or portable ACs, rated 7,000–10,000 BTUs, need less energy. They typically draw 1,500–2,000 watts at startup and 900–1,300 watts running. These are suitable for vans, teardrops, and single-room cooling.
How To Calculate Your RV Air Conditioner’s Watt Usage
Manufacturers often mention power ratings in amperes instead of watts. To estimate usages in watts, use:
| Formula | Example (120V System) |
|---|---|
| Watts = Volts x Amps | Watts = 120V x 15A = 1,800 W |
Check your AC’s data plate for amps and voltage, then calculate actual wattage for both starting and running conditions.
RV AC Power Consumption During Startup vs. Running
Startup watts (a.k.a. surge watts) can be as much as double or triple the running watts. This initial spike is crucial to consider for generator sizing or when using limited shore power. Once the compressor stabilizes, wattage drops to a steady operating level.
- A 13,500 BTU AC may draw 2,900W starting and 1,400W running
- A 15,000 BTU AC may use 3,300W starting and 1,800W running
How Many Watts Does An RV Air Conditioner Use With Other Appliances?
When traveling, you often run multiple devices with your AC: microwaves, fridges, TVs, and chargers. Balancing these appliances is essential to keep circuits from overloading.
| Appliance | Typical Wattage |
|---|---|
| RV Air Conditioner (13.5k BTU) | 1,400 W (running) |
| Microwave Oven | 900–1,500 W |
| Refrigerator (Compressor On) | 600 W |
| Coffee Maker | 800–1,200 W |
| TV/Entertainment Center | 150–300 W |
Calculate your combined wattage and ensure you don’t exceed generator or shore power limits.
Generator Sizing For Your RV Air Conditioner
One of the most common questions from RVers is: What size generator is needed for my RV AC? The answer depends on the AC’s starting wattage and what else you plan to power.
- A 2,000-watt generator may run a small AC in cool conditions, but won’t handle startup for 13,500 or 15,000 BTU units well.
- A 3,000–3,500-watt generator is recommended for most standard RV air conditioners, providing room for startup surge and other small devices.
- Inverters or parallel generators offered by Honda, Yamaha, and Champion are popular choices for RVers seeking reliable, efficient power.
Soft Starters And EasyStart Devices
Soft starters like Micro-Air EasyStart or Dometic’s SmartStart significantly reduce the starting wattage needed by your AC unit. With a soft starter installed, a 15,000 BTU AC that normally needs 3,200W to start may only require 1,800–2,000W.
- This enables you to run large ACs with smaller generators or even robust solar setups.
- Soft starters are a major upgrade for boondockers and off-grid travelers.
RV Air Conditioner Energy Efficiency Ratings
Energy efficiency is measured by EER (Energy Efficiency Ratio), which compares BTUs to electric input in watts. Higher EER values mean more cooling for less power. Modern RV ACs typically feature improved EERs, especially when paired with soft start units and regular maintenance.
- Check your model’s EER rating—aim for 8 or higher for optimal efficiency.
- Maintaining filters, coils, and sealing vents also boosts performance and energy savings.
Can An RV Air Conditioner Run On Solar Power?
Running an RV air conditioner fully on solar power is challenging due to high wattage draw. However, it’s possible with a robust solar array, high-capacity lithium batteries, and an inverter rated for your AC’s startup surge.
| Component | Recommended Specs |
|---|---|
| Solar Panels | 1,200–2,000W total array |
| Battery Bank | 400+ Ah lithium (at 12V) |
| Inverter | 3,000W pure sine wave |
For most RVers, running AC on solar is best for occasional use or with a small AC unit and favorable weather. Hybrid generator/solar systems offer more practical, year-round comfort.
Estimating RV Air Conditioner Runtime Per Power Source
How long can you run your AC on shore, generator, or battery power? This depends on available wattage, generator tank size, and battery bank capacity.
On Shore Power
Standard 30-amp RV hookups can usually run one AC and a few small devices; 50-amp hookups may handle two ACs and more appliances. Always check for campground circuit limits and avoid overloading.
On Generator Power
Runtime is limited by fuel tank size and load. A 3,500-watt generator powering one AC can run 8–12 hours on a full tank, depending on demand and generator efficiency.
On Battery (Inverter) Power
Even large battery banks deplete rapidly under AC load unless paired with solar charging or a soft start. For example, a 400Ah lithium bank will only run a 13,500 BTU AC for 2–3 hours before requiring recharge.
Tips For Reducing RV Air Conditioner Watt Usage
- Insulate windows and doors with reflective foil to keep out heat.
- Run fans and vent covers alongside AC for better airflow and faster cooling.
- Set your AC to 78°F or higher and use the energy-saving mode.
- Perform annual AC maintenance: clean filters and coils, check refrigerant, and inspect gaskets.
- Upgrade to a higher EER or inverter-based AC model for increased efficiency.
- Install a soft-start module for easier starting and generator compatibility.
Frequently Asked Questions About RV Air Conditioner Wattage
Can You Run Two RV AC Units On 30 Amps?
Generally, no—running two full-size ACs on a 30-amp supply exceeds breaker ratings. Some modern low-wattage models with soft starters may allow it briefly, but long-term use risks tripping breakers or damaging systems. A 50-amp hookup is recommended for dual-AC operations.
How Much Does It Cost To Run An RV AC?
At an average electricity rate of $0.15 per kWh: A 1,500W (1.5kW) AC running 8 hours daily costs about $1.80/day ($54/month). Off-grid, fuel and maintenance expenses for generators must be factored in.
Can I Run My AC While Driving?
Many motorhomes let you run the rooftop AC using the onboard generator while in motion. For towables, the AC generally runs only when plugged into shore/grid power or the generator at a stop, not while being towed by a vehicle.
Maintenance For Optimized RV Air Conditioner Power Consumption
- Inspect and clean or replace air filters monthly, especially in dusty climates.
- Wash condenser and evaporator coils annually.
- Keep roof vents and ducting sealed and unobstructed to maintain efficiency.
- Check shore power connections for corrosion and secure fit.
A well-maintained RV AC unit uses less power and provides reliable cooling all season long.
Summary Table: RV Air Conditioner Wattage Quick Reference
| BTU Size | Starting Watts | Running Watts | Recommended Generator |
|---|---|---|---|
| 7,000–10,000 | 1,500–2,000 | 900–1,300 | 2,000–2,200 W |
| 13,500 | 2,750–3,000 | 1,200–1,600 | 3,000–3,500 W |
| 15,000 | 3,200–3,500 | 1,500–2,000 | 3,500–4,000 W |
Key Takeaways
- RV air conditioner wattage depends on BTU size, startup surge, and operating conditions.
- Soft start devices lower required generator capacity, making off-grid AC use more feasible.
- Combine power planning with energy-saving tactics for maximum comfort and efficiency on the road.