Five years ago, "AC in a van" meant shore power or a generator. A $700-2,000 DC mini split running off a 400Ah LiFePO4 bank and 800W of solar has changed that — not for everyone, but enough that the old "you can't run AC off-grid" answer is no longer the right one.
A few years ago, solar and batteries were crazy expensive per watt and watt/hour, and the only air conditioners that were available used massive amounts of power - it really wasn't at all feasible to have an off-grid camper that would have an air conditioning system. The standard advice was: if you need AC, you need shore power or a generator. Period.
However, things have changed pretty dramatically on two fronts. First, solar panels and lithium batteries have gotten way, way cheaper - you can now build a 400Ah battery bank with 800+ watts of solar for what a 200Ah system would have cost five years ago. Second, and maybe more importantly, DC-powered mini split air conditioners have recently hit the market at surprisingly affordable prices - you can get one for around $700-2,000.
These are the air conditioners you see on the roof of pretty much every RV. They're all-in-one units - everything is contained in the box on your roof, and they blow cold air down into your space.
1,400W AC unit → ~1,600W pulled from batteries (after inverter losses)
= ~125A continuous at 12.8V
On a 400Ah LiFePO4 bank at 90% DoD: ~2.9 hours of runtime before the BMS cuts off.
Even with 800W solar perfectly positioned (~600W realized in peak sun), you're still net-negative by ~1,000W while the AC runs.
These are the new kids on the block, and they work quite differently. A mini split system has two parts: an outdoor compressor/condenser unit (the part that gets hot) and an indoor air handler (the part that blows cold air). They're connected by refrigerant lines that you run through a small hole in your wall.
500W DC unit = ~40A continuous at 12.8V (no inverter in the loop)
On a 400Ah LiFePO4 bank at 90% DoD: ~9 hours of runtime before BMS cutoff.
With 800W of solar in peak sun (~600W realized), you're net-positive by ~100W while it runs.
You've probably seen ads for portable AC units like the Zero Breeze Mark 2 or the EcoFlow Wave 2. The pitch is appealing: no installation, no drilling holes, just set it up and go. But there's a reason this guide focuses on mini splits.
Portable units have the same fundamental issue as traditional roof-mounted AC: the compressor sits inside your space. The compressor generates heat while trying to cool — so the unit is fighting itself. They vent hot air out through a window or hose, but it's inherently less efficient than a mini split where the hot part is completely outside the van. In a small van interior, this matters a lot.
The Zero Breeze at 2,300 BTU is simply not enough to meaningfully cool a van in real heat. It might take the edge off — dropping the interior a few degrees — but on a 95°F day, you're not going to feel "cooled." The EcoFlow Wave 2 at 5,100 BTU fares better, but you're still getting the low end of mini split performance at a similar price, with worse efficiency because of the self-contained design.
Both units also still draw significant power. The EcoFlow Wave 2 pulls 400-700W — comparable to a DC mini split, but with less cooling output per watt. You can buy EcoFlow's add-on battery so it doesn't tap your van's system, but that's another ~$350 and 17 lbs for a 1,159Wh battery that powers the AC for a few hours.
If any of those describe you, a portable could be a reasonable choice. But if you're building out a van and know you want AC, a DC mini split will cool better, more efficiently, for a similar price — it just requires installation.
The term "mini split" refers to the system being split into two units - hence "split." The compressor (the power-hungry, heat-generating part) sits outside, and the air handler (the part that blows cold air) sits inside.
"Mini" just means it's a small system designed for a single room/zone, as opposed to a whole-house system. Perfect for a van!
The honest answer: it depends, but it's way more feasible than it used to be.
If you have a large solar array, a beefy alternator charging setup, frequent access to shore power, or some combination of those — then yes, running a DC mini split off-grid is realistic. The key is having enough consistent power input to keep up with the draw. AC is one of the most power-hungry things you can run in a van, so your electrical system needs to be built with it in mind from the start.
Somewhere hot during the day but cool at night
Run AC during peak heat (when solar is also peaking), then turn it off at night and use your roof fan. This is actually pretty sustainable with a good solar setup.
Somewhere that's hot 24/7 (like desert summer)
You'll need a really big battery bank, or you'll need to supplement with shore power or a generator.
These are a bit more involved to install than traditional roof AC units:
Usually on the back doors or exterior wall
Usually on a wall or ceiling
Through your wall - needs proper sealing
Some units come pre-charged, others need professional charging
A 500W unit pulls ~40A continuous, so size for it: 6 AWG minimum (4 AWG with margin) and a 50-60A breaker on the load side. Larger 12,000 BTU units can pull 80A+ on startup — check the unit's spec sheet, not just the running watts.
The installation isn't rocket science, but it's definitely more complex than just cutting a hole in your roof and bolting down a traditional AC unit.
I wouldn't prioritize AC in the budget. A good roof fan (Maxxfan), proper airflow, and strategic camping (seeking shade, higher elevations, cooler seasons) will get you pretty far. AC is expensive, uses a lot of power even with the DC units, and adds complexity.
If you're going to be in genuinely hot conditions regularly, or if you have health issues that require AC, or if you just really value being cool - the new DC mini splits have changed the game enough that it's worth considering.
It's no longer a "you must have shore power" situation.
You're not going to match home AC performance on battery power alone, but you can make a hot van bearable, which is a pretty big upgrade.
One more thing: DC mini splits are still relatively new to the van world, so long-term reliability data is thin. You're taking more risk than with an established brand like Dometic. The cheap end of the band ($700-1,000 for a Vevor-class 12V cab unit) is forgiving if it dies after two seasons. The Velit and Mabru end of the band ($1,500-2,000) is a real bet — research the specific model and read recent owner reports before you commit.