A parking air conditioner is a 12V or 24V DC-powered cooling system that lets a truck, RV, van or work vehicle keep the cabin comfortable while the main engine is off, reducing fuel use, emissions and engine wear. Instead of idling the diesel engine to run the factory air conditioning, a parking AC draws from the vehicle battery or an auxiliary battery bank, so a driver can sleep, load or rest without burning fuel.

Vethy manufactures two main families of parking air conditioners: rooftop units that bolt onto the cab roof and split units that separate the condenser from the evaporator. Both lines come in 12V and 24V DC, and both use R410A refrigerant, which cools 20% more efficiently than the older R134a system while saving about 25% in power . The flagship VS02 Pro twin-rotor rooftop unit delivers 2800 W of cooling capacity and weighs 31 kg, with a footprint of 680 mm × 980 mm × 180 mm, and keeps noise in the 42 to 55 dB range.

Choosing the right unit is mostly about three things: the vehicle electrical system, the mounting style that fits the cab, and the size of the battery bank that will feed the compressor. Get those three right and a parking AC becomes a reliable overnight comfort system rather than a source of dead batteries.

• Up to 18 hours of continuous cooling on the VS02 Pro, so an overnight rest cycle is covered by a single charge.
• 2 hours is the typical installation time when a qualified technician mounts the unit.
• 2x cooling efficiency from the twin-rotor compressor design versus single-rotor equivalents.

Matching a unit to the vehicle prevents under-cooling and short battery life. Work through the three steps below to narrow the Vethy range.

Updated: 2026-05-19 · By Vethy Technical Team

Battery sizing is the detail that decides whether a parking air conditioner feels like a luxury or a liability. The Vethy DC range pulls its current from an auxiliary battery bank rather than the starter battery, so the bank has to be sized for the full rest cycle. As a rule of thumb, a 200 Ah or 250 Ah bank holds an overnight cycle with margin, while a 100 Ah to 150 Ah bank is fine for shorter daytime stops. Deep-cycle batteries are required; a standard starting battery will not tolerate repeated deep discharge.

The efficiency stack matters more than the headline cooling number. R410A refrigerant delivers about 20% higher cooling than R134a and 25% lower power draw , and the twin-rotor compressor provides 2x cooling efficiency . Together they let a smaller battery bank deliver up to 18 hours of cooling, the same number fleets validate in a 90-day over-the-road rollout and a 30 to 45-day regional rollout.

• Confirm the vehicle is 12V or 24V before ordering, so the compressor and low-voltage cutoff match the electrical system.
• Keep the unit in the 42 to 55 dB noise band so an overnight rest is genuinely restful.
• Expect a qualified technician to finish a rooftop or split install in about 2 hours.