RV HVAC Upgrade: Heat Pumps, 12V A/C, and Too Many Options

Thinking It’s Time for an HVAC Upgrade… But I’m Still Not Sure What Direction to Go

At my last house, I had a mini split heat pump system, and honestly, I loved how it worked. Quiet, efficient, and far better than traditional HVAC systems in a lot of ways. That got me looking into whether I could make something similar work in the RV.

One of the first things I looked at was a DIY-style residential heat pump system from MRCOOL. I’m confident I could make a system like that work in the RV if I really wanted to. The problem is that it would probably turn into a massive custom project and a royal pain in the ass to install cleanly.

More importantly, I want whatever route I take to be something I can realistically share with readers and YouTubers as a practical option — not a one-off science experiment that only works if you’re comfortable redesigning half your RV.

That led me to the next option: rooftop heat pumps.

Several companies now offer direct rooftop heat pump replacements for standard RV air conditioners. In theory, it’s a pretty appealing setup:

• air conditioning during the summer

• electric heat during cooler weather

• propane furnace backup when temperatures get too low for efficient heat pump operation

The more I researched it, the more I liked the idea.

Since I’m already running Dometic equipment, replacing my existing rooftop units with updated Dometic heat pump models appears to be the easiest route. From everything I’ve found so far, the thermostats and controls should be mostly plug-and-play.

If I switch to another manufacturer, it looks like I’d be dealing with thermostat replacements, rewiring, and compatibility issues. I’m not afraid of doing the work, but again, I’m trying to keep this grounded in solutions most RV owners could realistically tackle themselves.

Part of the reason I started seriously looking into all this was because my main living area A/C failed last summer — naturally during race season, parked in direct sun, on one of the hottest days of the year, with more race weekends still ahead of us.

The bedroom unit still works great though, which opened up another idea that I honestly still haven’t ruled out:

• remove both rooftop units

• relocate the rear bedroom unit to the main living area

• install a 12V air conditioner in the bedroom

That setup could potentially let us run air conditioning overnight at the track without running the generator all night long, which is extremely appealing.

I did attempt a repair on the front unit. I replaced the start/run capacitor, and technically it’s working again… sort of.

It cools, but not nearly as well as it should. My suspicion is that the refrigerant charge is low. Unfortunately, these rooftop RV units are sealed systems, so it’s not as simple as servicing an automotive or residential HVAC setup.

So after spending a lot of time researching systems, taking measurements, comparing options, and trying to figure out the smartest long-term setup…

I’ve basically come to the conclusion that I still haven’t decided shit.

The MRCOOL-style mini split system still interests me because I think it would ultimately be the quietest and most power-efficient option.

Replacing both rooftop units with updated Dometic heat pumps would definitely be the simplest and most straightforward route.

And swapping the front and rear units while experimenting with a 12V bedroom setup might honestly be the most interesting real-world test of all of them.

So for now, I guess I still have more thinking to do.

Potential cabinet/ locations for residential heat pump: