What type of air is used for anti-ice purposes?

High-pressure air is typically used for anti-ice purposes in aircraft systems. This air is supplied from the engine's compressor section and is needed to effectively heat critical aircraft surfaces, such as wings, engine inlets, and leading edges, to prevent the formation of ice. The use of high-pressure air allows for greater energy transfer, helping ensure that these surfaces remain clear of ice build-up, which can negatively impact aircraft performance and safety.

Low-pressure air, medium-pressure air, and recycled cabin air are less effective for anti-ice purposes due to their inability to maintain the necessary temperature and velocity needed for effective ice prevention. Low and medium-pressure air may not provide sufficient heating capability, while recycled cabin air is not suitable for this application since it is not designed to transfer heat efficiently in the specific areas where ice formation is a concern.