An environmental control system for a vehicle includes an environmental control system pack including a ram air circuit and a thermodynamic device. The ram air circuit includes a ram air shell having a ram inlet and a ram outlet and at least one ram air heat exchanger arranged within the ram air shell. A ram air fan is fluidly coupled to the ram air shell. A bypass conduit is fluidly connected to a source of compressed medium. The bypass conduit has an outlet end positioned adjacent to a surface of the ram air fan for delivering a compressed medium to the surface.