1. (1) Installation in attic spaces.

   1. (a) Entrance way providing access to equipment shall not be less than the largest piece of equipment to be replaced.
   2. (b) There shall be a vertical clearance of at least four (4) feet and six (6) inches for use by those conducting necessary examination. In addition there shall be a walkway not less than twenty-four (24) inches wide on the ceiling joist running from the attic opening to the equipment, without an obstruction.

2. (2) Installation in crawl spaces underneath buildings.

   1. (a) Entrance way providing access to equipment shall not be less than the largest piece of equipment to be replaced.
   2. (b) There shall be a vertical clearance of at least four (4’) feet and six (6”) inches unobstructed crawl space to the unit.
   3. (c) If four (4’) feet and six (6”) inches of clearance cannot be maintained, the unit shall be located no more than twelve (12’) feet from the entrance opening and a clear unobstructed crawl space not less than thirty (30”) inches in height and twenty-four (24”) inches in width shall be maintained.
   4. (d) Light fixtures in crawl spaces shall have guarded covers.

Authority: T.C.A. §§ 68-102-113, 68-102-143, and 68-102-150. Administrative History: Original rule certified June 10, 1974. Amendment filed October 24, 1974; effective January 17, 1975. Amendment filed April 20, 1978; effective May 22, 1978. Repeal and new rule filed October 27, 1981; effective December 11, 1981. Repeal and new rule filed June 28, 1984; effective July 28, 1984. Repeal and new rule filed March 12, 1987; effective April 26, 1987. Amendment filed June 27, 1990; effective August 11, 1990. Amendment filed September 22, 1993; effective January 28, 1994. Amendment filed November 4, 1996; effective March 7, 1997. Amendment filed November 14, 2008; effective January 28, 2009.