Through-the-wall central air conditioning heat pump

means a heat pump that is designed to be installed totally or partially within a fixed-size opening in an exterior wall, and:

(1) is not weatherized;

(2) is clearly and permanently marked for installation only through an exterior wall;

(3) has a rated cooling capacity no greater than 30,000 Btu/hr;

(4) exchanges all of its outdoor air across a single surface of the equipment cabinet; and

(5) has a combined outdoor air exchange area of less than 800 square inches (split systems) or less than 1,210 square inches (single packaged systems) as measured on the surface described in paragraph (4) of this definition.