Source:http://linkedlifedata.com/resource/umls/id/C0042491
MSH: Supplying a building or house, their rooms and corridors, with fresh air. The controlling of the environment thus may be in public or domestic sites and in medical or non-medical locales. (From Dorland, 28th ed),CSP: pattern of movement of air within a specified environment.,NCI: The act of moving air into and out of a space.