How is the AC system heat exchanger ventilated while on the ground?

The correct answer highlights the use of the Venturi effect to ventilate the AC system heat exchanger while the aircraft is on the ground. The Venturi effect occurs when air flows through a constricted section of ductwork, resulting in a decrease in pressure, which can create a suction effect that draws in outside air.

In the context of the Dassault Falcon 2000LXS, this means that when the aircraft is stationary, the design of the system allows outside air to be pulled into the heat exchanger for cooling purposes, enhancing the efficiency of the AC system even without the additional momentum provided by forward flight.

Using electrical fans would imply reliance on active electrical systems that may not always be necessary or operational while on the ground, which could be less efficient in terms of energy use. Cabin pressurization typically relates to maintaining pressure in the cabin environment rather than actively ventilating the heat exchanger. Circulating conditioned air is part of the overall AC operation but does not specifically address the mechanism utilized while on the ground to extract heat effectively from the heat exchanger. Therefore, the Venturi effect stands out as the most precise answer in this scenario.