Roof Mounted RV Air Conditioner: A Comprehensive Guide
The roof mounted RV air conditioner is a popular choice for travelers who want reliable cooling on the road. This guide explains how roof mounted units work, how to choose the right size, installation basics, power requirements, and maintenance tips. Readers will learn practical insights to optimize comfort while balancing energy use and budget.
What Is a Roof Mounted RV AC Unit?
A roof mounted RV air conditioner sits atop the vehicle rather than inside a window or portable unit. It consists of a condenser and evaporator connected by refrigerant lines, a fan, and a shroud that protects the system from weather. These units are designed to run on standard RV electrical systems and are engineered to withstand vibration and varying ambient temperatures. They provide efficient cooling for smaller campers and larger motorhomes alike when appropriately sized.
Key Features To Consider
- BTU Rating: Common sizes range from 13,500 BTU to 15,000 BTU or more. Bigger RVs may require 18,000 BTU units or dual-head configurations for even cooling.
- Energy Efficiency: Look for units with high SEER-like efficiency ratings and variable-speed blowers for quieter operation and better temperature control.
- Noise Level: Measured in decibels (dB), a lower number means less noise. Many enthusiasts prefer units under 60 dB on high and significantly quieter on low.
- Power Requirements: Verify voltage (usually 120V AC in the US), startup surge, and whether the RV’s inverter can support operation during boondocking.
- Installation Kit: A complete kit includes mounting frame, roof sealant, brackets, ductwork, and a roof vent cutout guide. A proper install prevents leaks and drafts.
- Brand And Service: Popular brands such as Dometic, Coleman-Mach, and Advent) offer broad dealer networks and easy-to-find replacement parts.
BTU Sizing And RV Load Planning
Choosing the right BTU rating depends on RV size, insulation, climate, and roof structure. As a rule of thumb, smaller trailers benefit from 13,500 BTU units, while larger fifth-w wheels and motorhomes may require 15,000 BTU or more. For extremely hot climates or poorly insulated spaces, consider dual-zone cooling or multiple units. Always calculate cooling load by floor area and consider ceiling height, solar gain, and occupancy to avoid undersized or oversized units that waste energy and reduce comfort.
Installation Basics
Proper installation is critical for performance and longevity. Steps include locating the best roof spot within weight and clearance limits, cutting the roof with precision, and applying a weatherproof sealant. A mounting frame distributes weight and reduces vibration. Electrical connections should meet code requirements and include proper fusing. If the unit will be used off-grid, plan for an adequate inverter and battery bank. For renters or DIY enthusiasts, many manufacturers offer installation manuals and professional installation options through dealers.
Power Requirements And Electrical System
Most roof top RV AC units run on 120V AC power at a standard home-like circuit, often through a 20-amp or 30-amp service depending on overall RV electrical capacity. Startup current can spike, so a dedicated circuit or a robust inverter may be necessary for off-grid use. Consider peak load when running other appliances such as a microwave or water heater. Some units feature dual power modes or soft-start tech to reduce initial surge and protect electrical components. Always verify compatibility with the RV’s electrical panel and shore power capabilities.
Maintenance And Troubleshooting
- Filters: Clean or replace air filters regularly to maintain airflow and efficiency.
- Condensate Drain: Ensure drains are unobstructed to prevent water buildup and mold.
- Coils: Periodically inspect and clean condenser and evaporator coils to maintain heat exchange efficiency.
- Sealant And Mounts: Check roof seals and mounting hardware for signs of wear or leaks, especially after weather events.
- Electrical Connections: Inspect wiring for loose connections or corrosion, and address any tripped breakers promptly.
Common Models And Brands
Two widely trusted brands for RV roof air conditioners are Dometic and Coleman-Mach. Dometic offers a range of 13,500 to 15,000 BTU units with efficient airflow and quiet operation. Coleman-Mach provides similar cooling capacity with durable construction and often lower initial cost. Other reputable options include Advent and Suburban for replacement components and outdoor compatibility. When choosing a model, compare warranty terms, service networks, and available replacement parts in the United States.
Energy Efficiency And Noise Considerations
Efficiency translates to lower electricity use and better performance in extreme heat. Look for units with variable-speed blowers and efficient compressors. Noise is often cited as a drawback for rooftop units; prioritizing models with lower dB ratings can markedly improve comfort, especially for long overnight use. In hot climates, consider a paired strategy: a high-efficiency unit combined with good RV insulation and shading to reduce heat gain.
Installation And Aftercare Planning
Before purchasing, measure the existing roof space and confirm load capacity. After installation, schedule a professional inspection to verify sealant integrity and electrical connections. Keep spare filters and routine cleaning supplies on hand to extend the life of the unit. For travelers, plan maintenance in seasonal stops to minimize downtime and ensure continuous comfort on the road.
Practical Tips For Choosing The Right Unit
- Match BTU to RV size and climate; avoid undersizing or oversizing for efficiency and comfort.
- Check compatibility with shore power and inverter capacity for off-grid use.
- Evaluate noise levels in the context of typical campsite environments.
- Choose a reputable brand with easy access to parts and service in the United States.
- Assess roof condition and mounting hardware before install to prevent leaks.
By understanding how a roof mounted RV air conditioner works, along with sizing, installation, and maintenance considerations, RV owners can optimize comfort, energy efficiency, and reliability during travel. The right unit enhances living space on the road and provides dependable cooling in diverse climates.