The present application provides a compressor inlet casing (100) and a method of operating a compressor (15). The compressor inlet casing (100) may include an inner bellmouth (110) and a bearing housing (140). The bearing housing (140) may include an integrally cast first half (150) connected to the inner bellmouth (110) and a cavity (180) positioned between the inner bellmouth (180) and the integrally cast first half (150) of the bearing housing (140).