Sometimes, when we are choosing a transport refrigeration unit or air conditioner for truck/van/bus, we may see some descriptions like “APU is compatible for all truck cooling”, “Split AC Electrical Standby is optional”. Laymen may confuse AC Electrical Standby with Auxiliary Power Unit, thinking that they are the same thing and both work as additional power supply when engine is off. Actually, they are quite different. Corun has explained what is Split AC Electrical Standby in previous article, and today let’s explore what is the Auxiliary Power Unit.

An auxiliary power unit (APU) is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft and naval ships as well as some large land vehicles.

The most common APU for a commercial truck is a small diesel engine with its own cooling system, heating system, generator or alternator system with or without inverter, and air conditioning compressor, housed in an enclosure and mounted to one of the frame rails of a semi-truck.

Electric APUs have started gaining acceptance. These electric APUs use battery packs instead of the diesel engine on traditional APUs as a source of power. The APU's battery pack is charged when the truck is in motion. When the truck is idle, the stored energy in the battery pack is then used to power an air conditioner, heater, and other devices (television, microwave oven, etc.) in the bunk.

All Electric Air Conditioners from Corunclima are compatible with Electric APUs. While APU is expensive and it takes about 15 hours to install, so normally APUs are installed on big rigs on which many devices need to be powered. For most trucks, simply installing an Electric Truck Air Conditioner is a quick solution favored by many drivers. For them, keeping air conditioner run is the main cause of idling, by choosing an Electric Truck Air Conditioner, or we call Parking Air Conditioner, idling time is greatly reduced, fuel is saved, and maintenance cost is lowered. Corunclima has 3 types of Parking Air Conditioner for choice: Back Mounted K20BS2, Top Mounted K20BT2, and Mono-block T20B.

Together with Corunclima, let’s enjoy the comfort brought by worry-free transport refrigeration unit and air-conditioning system for trucks, vans, and various types of vehicles!