Coleman-Mach Everest VS-18 18,000 BTU Rooftop Air Conditioner, Black

The Coleman-Mach Everest VS-18 is Coleman's variable-speed rooftop air conditioner, built to pull down the temperature in a big rig on a hot afternoon and then hold it there without much fuss. It puts out a full 18,000 BTU of cooling, which is about as much as you'll get from a single rooftop unit. So it's the one you reach for when you've got a large travel trailer, a fifth wheel, or a Class A motorhome and a smaller AC just can't keep up in July.

The thing that sets the Everest apart from a standard RV air conditioner is the variable-speed inverter compressor. A regular rooftop unit only knows two settings, full blast or off, so it slams on, overcools, shuts down, and then kicks back on a few minutes later. The Everest ramps its output up and down to match how hard the coach is actually working. Once the cabin hits your set temperature, it eases off and just sips power to hold the line. That means quieter running, fewer of those jarring on-off cycles, and a more even temperature end to end.

It's also a lot friendlier to your power. The Everest has an integrated soft-start built in, so it doesn't hit your generator or shore pedestal with a big surge every time the compressor spins up. Anyone who's tripped a breaker or watched the lights dim when the AC kicks on knows exactly why that matters. The soft ramp keeps startup draw down, which makes this unit a good match for generator-powered dry camping and for parks with touchy 30-amp service.

Airflow is handled by a 360 degree distribution design pushing up to 270 CFM. Cold air spreads out across the coach instead of dumping straight down under the unit. And here's the flexible part: the same VS-18 runs ducted or non-ducted, so you don't have to order a different model depending on your roof. If your rig has ductwork in the ceiling, it feeds the ducts. If it doesn't, you run it through a non-ducted ceiling assembly and cool a single open space. One unit covers both setups.

On the install side, the Everest drops into a standard 14.25 inch by 14.25 inch roof opening, the same cutout most RV rooftop units use, so it's a straight swap on a lot of coaches. The base pan is powder-coated steel to stand up to sun, rain, and road grime year after year. The shroud is black. Just know it's a 68 pound unit going up on a roof, so plan on two people and a solid, safe way to get it up there. This isn't a one-person job.

One important thing to sort out before you order: the VS-18 is the rooftop unit only. The ceiling assembly (part 2111-0044) and the digital thermostat (part 2111-0043) are sold separately, and you need both to finish the job. A lot of folks miss that and end up waiting on parts mid-install. So if this is a fresh setup rather than a straight replacement, add the matching ceiling assembly and thermostat to your order up front and save yourself the delay.

Who's it for? If you camp in real heat, run a bigger coach, or you're just tired of the constant on-off racket from an old rooftop unit, the variable-speed Everest is a clear step up. If you only camp in mild weather or you've got a small teardrop, you're probably paying for capacity and features you won't lean on. And one more note: this is a cooling air conditioner, not a heat pump, so it won't warm the coach on cold mornings. For heat you'll still lean on your furnace. But for knocking down the heat on a scorcher and keeping it comfortable overnight, the VS-18 does the job and does it quietly.