Any person who shall prove that he operates a legitimate place of business and has a State tax exemption number and has been engaged in the business of installing, altering, repairing, cleaning or adding to any air-moving equipment systems on a full time scale for a period of one year prior to the passage of this article [February 20, 1960] shall be issued a license without passing the examination and securing the certificate of qualification as an air-moving equipment contractor.
(1970 Code Sec. 14-15)