When RV owners ask us about air conditioning, the first question isn't which brand — it's which architecture. A permanently installed rooftop unit and a portable unit solve the same problem in very different ways. Using two units we stock — the Dometic Penguin II rooftop AC and the Cybertake S2 Pro portable — here's how to decide.
Raw Cooling Power: Rooftop Wins
There's no contest on output. The Penguin II delivers 15,000 BTU (a 13,500 BTU version is also available) in a low-profile housing that works with both ducted and non-ducted systems — enough to cool a full-size travel trailer in serious heat. The S2 Pro's 5,100 BTU is sized for spaces up to about 130 sq. ft.: tents, teardrops, vans, and small campers. If you need to cool a 25-foot trailer in Arizona in August, you need rooftop-class BTU.
Power Draw: Portable Wins Off-Grid
That rooftop power comes at a price: a 120V unit like the Penguin II realistically wants shore power or a generator. The S2 Pro flips the equation — in Eco+ mode it runs up to 8 hours on 1 kWh, and it accepts three power sources: a 100–240V wall outlet, 12V/24V vehicle power, or 48V DC from a portable power station (boost converter sold separately). Pair it with solar panels and a battery bank from our Victron Energy collection and you have climate control with no hookups at all.
Installation and Flexibility
A rooftop unit is a real installation: it occupies your roof vent opening, adds height, and stays with the rig. In return it consumes zero living space and is always ready. The S2 Pro needs no installation — about 30 seconds with the included hoses and adapters — and moves between your trailer, your tent, and your garage. It also does something the rooftop unit can't: 6,100 BTU of heating, which turns it into a four-season device.
Noise and Durability
Rooftop units transmit compressor noise through the roof structure. The S2 Pro runs at about 40 dB — quieter than a dishwasher — and its IPX4 water-resistant shell with waterproof buttons is built to live outdoors.
How to Choose
- Full-size trailer or fifth wheel, campgrounds with hookups: rooftop. Get the Penguin II 15,000 BTU and, for manual-control setups, the matching Dometic air distribution box.
- Tent, van, teardrop, or small camper — especially off-grid: portable. The Cybertake S2 Pro cools, heats, and sips battery power.
- Big rig that boondocks: many owners run both — rooftop for hookups, portable for the bedroom overnight on battery.
Browse all RV air conditioners and RV appliances — every unit ships from Upland, CA. For a deeper look at the portable option, read our full Cybertake S2 Pro review.