What you need to know before installing camper AC
Installing air conditioning in a camper requires three separate decisions: whether your camper's roof and frame can handle the weight, whether your electrical system can supply the power, and which type of unit fits your space and budget. Most camper owners choose a roof-mounted unit because it saves interior space, but some opt for portable or window units depending on their rig size and power availability. The installation itself is straightforward if you have basic tools, but the electrical work — running a dedicated circuit and upgrading your power source — often requires a licensed RV electrician.
The cost varies widely. A basic roof-mounted RV air conditioner runs $400 to $800 for the unit alone, plus $300 to $1,000 for professional installation if you hire an electrician. Portable units cost less upfront ($200 to $500) but draw more power and take up living space. Before you buy anything, check your camper's dry weight capacity, measure your roof, and have your electrical system inspected.
Key Takeaways
- Roof-mounted AC units are the most common choice for campers because they cool efficiently and don't use interior space, but your roof must support the weight and your electrical system must handle the draw.
- Your camper's battery and converter need to be upgraded or supplemented with a generator to power most AC units, since standard RV batteries cannot sustain air conditioning for more than a few minutes.
- A dedicated 30-amp or 50-amp circuit run from your main panel to the AC unit is required by code and prevents the unit from tripping breakers or overheating wiring.
- Professional installation by an RV electrician typically costs $300 to $1,000 and handles the electrical work, roof sealing, and ductwork — the parts most owners should not attempt themselves.
Checking your camper's weight and roof capacity
Every camper has a dry weight limit listed in the owner's manual or on the manufacturer's placard, usually mounted inside a cabinet or on the frame. Subtract the weight of your current equipment and supplies from this limit to find how much weight you can add. Most roof-mounted AC units weigh 80 to 120 pounds, so this is usually not a problem for travel trailers or motorhomes — but it can be for lightweight teardrop trailers or older rigs.
Beyond weight, check the roof material and structure. Aluminum roofs are standard and can handle a roof unit, but fiberglass or rubber roofs require reinforcement brackets to distribute the load. Look at your roof from inside the camper to see if there are roof beams or joists; if the roof feels soft or flexes when you walk on it, the structure may not be adequate. If you are unsure, a dealer or RV service center can inspect the roof for $50 to $150 and tell you whether reinforcement is needed.
Understanding your electrical system and power requirements
Most camper air conditioners draw 13 to 15 amps when running, which is far more than a standard 12-volt battery system can supply. A fully charged RV battery can power a small AC unit for only 5 to 15 minutes before the voltage drops too low. This means you must either run the AC while plugged into shore power (a campground pedestal) or use a generator.
Shore power comes in two sizes: 30-amp service (common in older campgrounds) and 50-amp service (standard in newer parks). A 30-amp service can run one AC unit but little else; a 50-amp service can run two units plus other appliances. If your camper is not equipped for the service level you need, an electrician can upgrade the inlet and internal wiring, a job that costs $500 to $2,000 depending on the camper size.
If you plan to use a generator, you need one rated for at least 3,500 watts to start an AC unit (the startup surge is higher than the running draw). Portable generators cost $400 to $1,500 and must be run outside the camper. Built-in generators, which are mounted under the camper and run on propane or diesel, cost $3,000 to $8,000 installed but are quieter and more convenient.
Choosing between roof-mounted, window, and portable units
Roof-mounted units are the standard choice because they cool the entire camper efficiently, mount permanently, and do not take up interior space. They require professional installation and a dedicated electrical circuit, but they are the most reliable option for full-time or frequent use. Models from Dometic, Coleman, and Advent are common in RV supply stores and online retailers.
Window or side-wall units cost less ($200 to $400) and can be installed by the owner in many cases, but they cool only the room they are in and require a window or wall opening. They draw slightly less power than roof units but still need a dedicated circuit. Portable units on wheels are the cheapest option ($150 to $300) and require no permanent installation, but they are noisy, less efficient, and take up floor space.
For most campers, a single roof unit is the best choice. If your camper is large (over 35 feet) or you spend time in very hot climates, two smaller units or one larger unit may be necessary. Check the BTU (British Thermal Unit) rating: a unit rated 13,500 BTU is standard for a 30-foot camper, while larger rigs may need 15,000 BTU or more.
Running the electrical circuit and wiring
The AC unit must have its own dedicated circuit run directly from your main electrical panel. This circuit should be protected by a breaker sized for the unit (usually 20 amps for a standard unit) and wired with 12-gauge or 10-gauge wire depending on the distance from the panel to the roof. Running this circuit yourself is not recommended unless you are experienced with RV electrical systems, because improper wiring can cause fires or electrocution.
A licensed RV electrician will run the wire through the walls or under the floor, install the breaker, and connect the unit to the circuit. They will also seal any holes in the roof or walls to prevent water leaks. This work typically takes 4 to 8 hours and costs $300 to $1,000 depending on your camper's layout and the distance the wire must travel.
If you are upgrading from a 30-amp to a 50-amp service, the electrician will also replace the inlet on the outside of the camper and upgrade the internal wiring from the inlet to the main panel. This is a larger job that can take 8 to 16 hours and cost $1,000 to $2,500.
Installing the roof unit and sealing the opening
Once the electrical circuit is in place, the AC unit is mounted on the roof using brackets and bolts. The opening in the roof must be sealed with a gasket and sealant to prevent water leaks — this is the most common source of problems after AC installation. Most units come with a gasket and instructions, but the sealant used (usually Dicor or similar RV-grade caulk) must be applied correctly.
The ductwork inside the camper routes cool air from the unit to the living space. Some units have flexible ducts that can be routed through cabinets or walls; others have a fixed plenum that requires more careful placement. The installer will insulate the ducts to prevent condensation and position them to avoid blocking cabinets or windows.
If you hire a professional, they will handle all of this. If you install the unit yourself, pay close attention to the gasket and sealant — a poor seal will lead to water damage that costs far more to repair than the installation would have cost.
Testing and troubleshooting after installation
After installation, test the unit while plugged into shore power at a campground or with a generator running. The AC should cool the camper to your set temperature within 15 to 20 minutes. If it does not, check that the thermostat is set correctly, the air filter is clean, and the condenser (the outdoor part on the roof) is not blocked by leaves or debris.
If the breaker trips when you turn on the AC, the circuit may be undersized or there may be a short in the wiring. Turn off the unit, check that nothing else is running on the same circuit, and try again. If it trips again, turn off the breaker and call your electrician — do not keep trying, as this can damage the wiring.
If the unit runs but does not cool, the refrigerant may be low or the compressor may be failing. This requires service by an RV technician and is usually covered under warranty if the unit is new. Most roof units come with a one-year parts warranty and a five-year compressor warranty.
Frequently Asked Questions
Can I install a camper AC unit myself?
You can install the physical unit on the roof if you are comfortable working at heights and have basic tools, but the electrical work should be done by a licensed RV electrician. Running a dedicated circuit, upgrading your service panel, and sealing the roof are the parts that require informed and code compliance.
How much does a camper AC installation cost?
A roof-mounted unit costs $400 to $800, and professional installation runs $300 to $1,000. If you need to upgrade your electrical service from 30-amp to 50-amp, add another $1,000 to $2,500. Portable units cost less upfront but may require a generator, which adds $400 to $8,000 depending on the type.
Will a camper AC run on battery power?
No. A standard RV battery can power an AC unit for only 5 to 15 minutes. You must either plug into shore power at a campground or run a generator. Some owners use a combination: shore power when available and a generator when boondocking.
What size AC unit do I need for my camper?
A 13,500 BTU unit is standard for campers up to 30 feet. Larger rigs or those in very hot climates may need 15,000 BTU or two smaller units. Check your camper's manual or ask a dealer for the recommended size based on your specific model.
How do I prevent water leaks after AC installation?
The gasket and sealant around the roof opening are critical. Use RV-grade caulk (Dicor or equivalent), explore it generously, and let it cure fully before exposing the roof to rain. Inspect the seal annually and reseal if you see cracks or gaps.