Key takeaways
- Use the correct roof gasket and tighten mounting bolts evenly. Over-compression can distort the pan and transmit vibration.
- Check that the blower wheel is not rubbing and that the shroud is secure.
- Seal gaps between the ceiling assembly and ductwork so air does not hiss through openings.
- Choose an inverter unit if sleeping noise and low-load operation are more important than the lowest purchase price.
The best RV air conditioners for most campers are the Coleman-Mach 3 Plus for value and broad compatibility, the Dometic Brisk Air II for a familiar replacement installation, and an inverter-equipped unit such as the Dometic FreshJet for quieter, more efficient operation when shore power or a generator is limited.
Best RV air conditioners compared
RV air conditioners are usually rated at 13,500 or 15,000 BTU per hour. The larger rating does not automatically make a unit better: a 15,000-BTU model can cool a large fifth wheel faster, but it normally draws more power and may be excessive for a small, well-insulated trailer. The table below compares widely available rooftop model families; exact electrical and sound specifications can vary by submodel, voltage, control board, and installation.
| Model or model family | Cooling capacity | Typical running draw | Approximate sound character | Best RV size | Installation notes |
|---|---|---|---|---|---|
| Coleman-Mach 3 Plus | 13,500 or 15,000 BTU/h | About 12–14 A at 120 V | Conventional rooftop-unit noise | Small to large trailers and motorhomes | Works with common 14 x 14-inch roof openings; ducted and non-ducted configurations are available |
| Coleman-Mach 8 Plus | 13,500 or 15,000 BTU/h | Roughly 11–14 A at 120 V | Lower-profile unit, but still audible indoors | Trailers with roof-height or clearance concerns | Confirm rooftop clearance and the correct ceiling assembly before ordering |
| Dometic Brisk Air II | 13,500 or 15,000 BTU/h | About 12–15 A at 120 V | Typical non-inverter rooftop-unit noise | Pop-ups, travel trailers, fifth wheels, and motorhomes | A practical replacement when the existing Dometic wiring and ceiling control system are compatible |
| Dometic Penguin II | 13,500 or 15,000 BTU/h | About 12–15 A at 120 V | Similar compressor sound; streamlined exterior | RVs needing a low-profile rooftop housing | Check ducted controls, gasket dimensions, and roof load before replacing another brand |
| Dometic FreshJet inverter series | Capacity varies by version, commonly around 9,000–13,500 BTU/h | Variable; often lower than fixed-speed units after startup | Generally quieter at partial load | Small and medium RVs, especially those using limited shore or generator power | May require a compatible control system and careful confirmation of roof-opening and wiring requirements |
| Furrion Chill | 13,500 or 15,500 BTU/h, depending on version | Approximately 12–15 A at 120 V | Conventional rooftop-unit noise | Medium and large travel trailers and fifth wheels | Often sold in ducted and non-ducted kits; match the ceiling assembly to the existing air distribution system |
Amperage figures are useful planning estimates, not a substitute for the electrical label on the exact unit. Compressor startup can briefly demand substantially more current than the running figure, which is why a generator that appears large enough on paper may still trip its overload protection.
Best choice by RV and camping situation
| Your situation | Recommended direction | Why |
|---|---|---|
| Small camper or pop-up under about 20 feet | 9,000–13,500 BTU inverter or 13,500 BTU fixed-speed unit | A 15,000-BTU unit may cycle too aggressively and consume more generator capacity than necessary |
| Medium travel trailer around 20–30 feet | 13,500 BTU; choose 15,000 BTU for poor insulation or strong sun exposure | This is the range where a single rooftop unit is usually a sensible balance |
| Large fifth wheel or motorhome over about 30 feet | 15,000 BTU, or two units where the roof and electrical system support them | One unit may cool the living area while leaving the bedroom hot, particularly in high temperatures |
| Frequent generator or battery-based camping | Inverter rooftop air conditioner | Variable-speed operation can reduce surge stress and average consumption after the RV reaches temperature |
| Direct replacement of a failed rooftop unit | Same-brand replacement, such as Brisk Air II or Coleman-Mach | Reusing the existing ceiling assembly and thermostat can make the installation less disruptive |
| Low-clearance roads, storage, or wooded campsites | Low-profile design such as the Coleman-Mach 8 Plus or Dometic Penguin II | Reducing rooftop height can matter more than a small difference in cooling capacity |
Cooling capacity: how much is enough?
Use 13,500 BTU as a starting point for many medium RVs, then adjust for conditions rather than choosing the largest available compressor. A dark roof, large unshaded windows, weak insulation, high humidity, and interior occupancy all increase the heat load. A well-insulated trailer parked in shade can feel comfortable with less capacity than a poorly insulated trailer of the same length in full sun.
For a 15,000-BTU unit, the theoretical cooling rate is 15,000 BTU per hour, but that is not the same as removing 15,000 BTU from the RV under every condition. Outdoor temperature, airflow, refrigerant charge, dirty filters, and duct leakage affect real performance. If the unit runs continuously without lowering the interior temperature, inspect airflow and insulation before assuming that a larger model will solve the problem.
Power draw and generator sizing
A useful first calculation is:
Electrical power = volts × amps.
For example, a rooftop unit drawing 13 amps on a 120-volt circuit uses approximately 1,560 watts while the compressor is running:
120 V × 13 A = 1,560 W.
Add a refrigerator, converter, television, lights, and chargers, and a 2,000-watt generator has little reserve. A 3,000-watt generator provides more practical headroom, but startup surge still matters. Soft-start devices can reduce the compressor’s starting demand on compatible air conditioners, although they do not reduce the unit’s continuous cooling load.
On a 30-amp RV hookup, the theoretical maximum is about 3,600 watts:
120 V × 30 A = 3,600 W.
That limit is shared by every appliance. Running an air conditioner while using a microwave, induction cooktop, electric water heater, or hair dryer can trip the pedestal breaker even when the air conditioner itself is working normally. An inverter model is especially useful when the campsite has a restrictive hookup because it can ramp down after the initial heat load is removed.
Noise: what the specifications do not tell you
Rooftop units put the compressor directly above the ceiling, so even a well-installed conventional model can be clearly heard inside. Manufacturer sound ratings are not always measured under identical conditions, making direct comparisons unreliable. In practice, installation often matters as much as the model:
- Use the correct roof gasket and tighten mounting bolts evenly. Over-compression can distort the pan and transmit vibration.
- Check that the blower wheel is not rubbing and that the shroud is secure.
- Seal gaps between the ceiling assembly and ductwork so air does not hiss through openings.
- Choose an inverter unit if sleeping noise and low-load operation are more important than the lowest purchase price.
A low-profile rooftop shell reduces exterior height, but it does not necessarily make the compressor quiet. Do not select a low-profile model solely for its advertised shape.
Installation and compatibility checklist
Most replacement rooftop air conditioners use a nominal 14 x 14-inch roof opening, but the opening size alone does not guarantee compatibility. Before ordering, check these points:
- Measure the roof opening and roof thickness. Confirm that the replacement gasket and mounting hardware cover the existing footprint without contacting roof ribs or wiring.
- Identify ducted or non-ducted airflow. A ducted RV sends air through ceiling channels; a non-ducted assembly discharges from the ceiling unit. The replacement must match the RV’s air path.
- Check the control system. Thermostats, control boards, temperature sensors, and communication wiring are not universally interchangeable between Dometic, Coleman-Mach, Furrion, and other systems.
- Verify the circuit. Confirm breaker size, wire gauge, shore-power capacity, and generator capability. Do not enlarge a breaker to stop nuisance trips without checking the wiring.
- Inspect the roof structure. Water damage, soft decking, or a sagging opening should be repaired before installing a heavier replacement.
- Plan for lifting and sealing. Rooftop units are heavy and awkward. Disconnect power, protect the roof membrane, use the supplied gasket, and follow the manufacturer’s bolt-torque instructions.
For a simple replacement, matching the old unit’s brand, capacity, duct configuration, and control method is usually safer than selecting a technically superior model that requires a new ceiling assembly.
Which RV air conditioner should you buy?
Choose the Coleman-Mach 3 Plus when you want a common, powerful fixed-speed replacement with broad availability and straightforward 13,500- or 15,000-BTU options. Choose the Dometic Brisk Air II when your RV already uses compatible Dometic controls or when a like-for-like replacement is the priority. Choose the Dometic Penguin II or Coleman-Mach 8 Plus when roof clearance is important. Choose a Dometic FreshJet inverter when lower average power use and smoother, quieter operation justify a higher installation and purchase cost. For a large RV with intense heat gain, the Furrion Chill or a 15,000-BTU Coleman-Mach or Dometic unit is the more appropriate capacity class.
Typical market pricing is roughly $400–$600 for many standard rooftop units, while inverter systems, complete ceiling assemblies, control upgrades, and professional installation can push the total substantially higher. The right purchase is the one that matches your RV’s roof opening, duct system, electrical capacity, and heat load—not simply the unit with the largest BTU number.
