Real air conditioning can cool a campervan, but “12V” alone tells you little about the cooling effect or the electrical system required. Compare the exact technology, heat exhaust arrangement and input power before choosing a unit.
This is a research guide, not a test of individual air conditioners. It replaces earlier blanket claims about cooling performance, prices and minimum battery sizes.
A fan, evaporative cooler and air conditioner are different
A fan moves air. A small water-fed evaporative cooler adds moisture as water evaporates. Neither should be assumed to offer the same cooling performance as a refrigerant compressor air conditioner.
A compressor system must reject heat outside the space it is cooling. Check how a proposed installation will do that: a roof-mounted unit, a split system and a portable unit with ducts have different requirements. A product photograph showing a compact box in a van does not demonstrate a complete working installation.
Portable does not mean a cigarette-lighter appliance
For example, the EcoFlow WAVE 3 manual lists 1,800W cooling capacity and 690W rated cooling input on AC power. Cooling capacity and electrical consumption are different measurements. The manual also specifies compatible power inputs and duct assembly; do not assume its DC connection can be wired to any 12V vehicle socket.
The manual explains how enclosed-space use expels exhaust air through ducts. Check the supplied adapters, opening arrangement, permitted duct routing and drainage instructions before deciding that the unit fits your van.
Roof systems need installation planning
Roof-mounted equipment changes the vehicle's height and weight distribution and requires an appropriate opening and support. Confirm fit, roof construction, electrical supply and installation requirements for the exact model with the supplier or a competent installer.
Dometic's FreshJet information is one manufacturer starting point for researching roof systems. A model name or a cooling-capacity number is not proof that it can run directly from your leisure battery. Read that model's current installation manual and electrical specifications.
Calculate energy before buying
Use electrical input power for your energy budget, not cooling capacity in watts or BTU. For illustration, a constant 690W load running for four hours uses:
690W × 4 hours = 2,760Wh
That is a calculation using the WAVE 3's rated AC input, not a measured four-hour consumption result. Cycling, operating mode, temperature, installation and conversion losses affect actual use. Add the fridge, lighting and other loads before comparing the total with usable battery capacity.
Check continuous and peak supply requirements, inverter compatibility where relevant, cable protection and charging arrangements. A solar-panel wattage on its label does not guarantee the same output throughout a summer day. Have the electrical design checked rather than relying on a universal “minimum battery size”.
Reduce the cooling load too
Shade, suitable window covers and planned ventilation can reduce heat gain or help remove accumulated heat. They do not guarantee a safe internal temperature. Keep security, weather and the manufacturer's ventilation requirements in mind when deciding which openings can remain open.
Choose equipment for your measured space and realistic travel conditions. Avoid a product simply because it promises an unspecified temperature drop: ask what space, ambient conditions and installation produced that claim.
Pets and unattended use
Do not use a cooling appliance as justification for leaving a dog unattended in a parked vehicle. Power, controls or the appliance can fail. The RSPCA's guidance on dogs in hot cars explains the risk.
What to check on a shortlist
- Is it a compressor air conditioner or a different cooling device?
- What are its actual electrical input and permitted power connections?
- How will heat exhaust and condensate be managed?
- Does the exact installation fit your van and comply with the manufacturer's instructions?
- What will power it for the intended period, and how will that energy be replaced?
Manufacturer documents checked on 24 October 2026. Check the exact supplied model before buying; this guide does not quote a current retailer price or promise a temperature reduction.
