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Elements of Mechanical Construction
Mechanical construction is a dynamic industry, and projects come in all shapes and sizes—from small residential homes to large-scale commercial buildings. Contractors also vary in the type of work they do, including:

HVAC Systems: includes heating, ventilation, and cooling/air-conditioning equipment.
Refrigeration Systems: the artificial cooling of a space, substance, or system; this is done either by transferring heat around or moving it from one area to another.
Plumbing: includes pipes, tanks, fittings, and other elements that control the water supply, heating, and sanitation of a building.
Electrical Systems: a network of electrical components that supply, distribute, and use electrical power; includes overhead and underground lines, poles, transformers, and other equipment.