What is recommended to counteract freezing during the evacuation of a low pressure system with large amounts of moisture?

To effectively manage moisture in a low-pressure system during evacuation and prevent freezing, increasing the pressure in the system with nitrogen is the recommended approach. When moisture is present, it can freeze at low temperatures, creating ice blockages that hinder the evacuation process. By introducing nitrogen into the system, you elevate the pressure, which raises the boiling point of any moisture present. This process allows moisture to be removed in a gaseous state rather than solidifying into ice.

Using chilled nitrogen could potentially lower temperatures and exacerbate freezing issues, while heated refrigerant might introduce more complications without effectively addressing the moisture problem. Water vapor is not a viable solution, as it would only contribute to the existing moisture issue rather than alleviating it. Increasing pressure with nitrogen facilitates a more efficient evacuation process, ensuring moisture is removed without the risks associated with freezing.