In this subtitle, the following words have the meanings indicated.
(1) "Pursuit of the mechanical trade or business" means an act of installing, maintaining, or repairing air conditioning, heating, or refrigeration systems excluding the transport of materials and equipment to the job site, the act of rigging for placement of equipment, the act of insulating and components of the system, and the act of manufacturing and assembling such systems in a shop or manufacturing environment not on the job site. For purposes of this definition, "refrigeration system" means a system used to cool a surface or area below 55 degrees Fahrenheit or 12.8 Celsius.
(2) "Ventilation" means a system of supply or removal of air by natural or mechanical means.
(1985 Code, Art. 16, § 11-101)