ZERO BREEZE Mark 3 AC

The ZERO BREEZE Mark 3 is a 48V battery-capable portable air conditioner rated at 1550W / 5,280 BTU of cooling, built for the kind of small sleeping and living spaces found in vans, trailers, rooftop tents, boats, semi-truck cabs and tiny houses. The cabinet measures 22" x 10" x 12" and weighs 22 lb, so one person can reposition it without tools or permanent mounting, and it carries an IPX4 moisture rating. ZERO BREEZE sizes it for areas of roughly 100 to 150 sq. ft. and is direct about the limitation: this is personal and small-area cooling, not a whole-room system. Four configurations are offered, and they differ only in how many 1022Wh Mark 3 batteries come with the unit - Z30 is the AC on its own, Z30P pairs it with one battery, Z30PE with two, and Z30PE+Z30B with three.

Cooling runs off a 48V micro-compressor with R290 refrigerant, and ZERO BREEZE quotes a 500W rated input for cooling. Seven operating modes are selectable - Rocket, Cool, Sleep, Fan, Dry, Care and Heating - across four fan speeds, with a 2.4G remote in the box and a beta companion app for iOS and Android. The thermostat covers 61 to 82 degrees F when cooling and 64 to 88 degrees F when heating, and dehumidification works across a 15 to 90% RH range. Heating is rated at 1700W / 5,800 BTU, though ZERO BREEZE positions it strictly as a supplementary function that only works above 50 degrees F and recommends a primary heat source alongside it. Care Mode applies a PI algorithm to compressor speed so outlet air reaches the setpoint sooner, and Sleep Mode is quoted at 46 dB. Rated operating voltage is 48V DC with a 38 to 58.5V working window; ambient operating range is 50 to 104 degrees F, with storage permitted from 14 to 140 degrees F.

This is a compressor-based air conditioner, not an evaporative cooler, so it produces hot exhaust air that has to go somewhere. The Mark 3 uses a dual-hose arrangement: the rear carries separate intake and exhaust paths, pulling outside air across the condenser and pushing the heated air back outside, which keeps the interior from going into negative pressure and drawing in unconditioned air. The front of the unit delivers the cold air, and an optional front outlet duct aims it at a specific spot. ZERO BREEZE states that ducts are not required in open spaces, but that in enclosed spaces such as tents, vans or boats the rear dual ducts should be used - and that the front and rear ducts need to draw from different air sources, because, in their words, "Drawing air from the same enclosed area can reduce cooling efficiency and cause hot air recirculation." Vehicle-specific window kits, a boat kit, a universal DIY kit and a tent venting kit are all sold separately. Condensate handling is automatic: a water-level sensor and internal pump run an active drain, a drainage pipe is included and is connected during setup, and an E18 overflow-protection error points to a kinked, blocked or submerged drain hose.

Power is flexible. The 100-240V, 50/60Hz wall adapter is in the box and will run the unit continuously with no battery attached. The Mark 3 is not restricted to ZERO BREEZE's own battery either - it accepts 110-240V AC, 48V DC, or 12-36V DC through the 48V booster. With Mark 3 batteries fitted, a battery latches under the unit and shares charge level, estimated runtime and charging status with the AC on the remote or in the app, pass-through charging lets the unit keep cooling while the battery takes charge, and chained batteries hand off automatically with no manual swapping. ZERO BREEZE's published stackable runtime figures are 2-7 hours on one battery, 4-14 hours on two batteries and 6-21 hours on three batteries, and they note actual runtime shifts with mode, ambient temperature and humidity.

What's in the Box

• Mark 3 air conditioner unit
• 100-240V wall adapter
• 2.4G remote control
• Drainage pipe
• Front outlet duct
• Front and rear inlet ducts
• Rear outlet duct
• Four duct adapters
• User manual
• Mark 3 batteries are included only on the Z30P, Z30PE and Z30PE+Z30B configurations; window, boat and tent venting kits are not included and ship as separate items