An auxiliary power unit (APU) is a device installed on semi trucks to provide an independent source of electrical power for air conditioning and other electrical systems without having to idle the truck engine. APUs are becoming increasingly necessary in many parts of the world due to regulations limiting idling times, as well as the growing cost of fuel. While there are many different types of APUs, they all work in roughly the same way.
The most common type of APU uses an internal combustion engine that is fueled by either diesel or gasoline. This engine drives an alternator, which generates electricity to power all of the truck’s electrical systems.
Some APUs also use a battery system that stores energy generated by the alternator, allowing it to be used when the main engine is not running. This makes them especially useful for long-haul truckers who may have to park and rest for extended periods.
Another type of APU uses a heat exchange system instead of an internal combustion engine. These units typically run off either diesel or propane fuel and use a heat exchanger to transfer heat from the engine exhaust into cool air for climate control inside the cab. This type of unit is more efficient than those powered by an internal combustion engine, as it does not require any fuel input when in operation.
Most modern APUs are equipped with additional features such as battery chargers and inverters that allow them to provide power even when they are not running. Inverters convert direct current (DC) power from the battery into alternating current (AC) power that can be used to operate lights, computers, and other AC-powered equipment inside the cab.
An APU can drastically reduce fuel costs for semi truck drivers by eliminating idling time and providing a reliable source of electricity without having to run the main engine. The installation cost can be expensive depending on which model you choose, but it can pay for itself over time with savings on fuel costs.
In conclusion, an auxiliary power unit (APU) is a device installed on semi trucks that provides an independent source of electrical power without having to idle the truck’s main engine. Different types of APUs exist that utilize either internal combustion engines or heat exchange systems powered by diesel or propane fuel.
They come with additional features such as battery chargers and inverters that allow them to provide AC power when they are not running. An APU can save money in the long run by eliminating idling time and providing reliable electricity while reducing fuel costs at the same time.