Work involves the regular, and at times sustained, performance of heavier physical tasks such as walking over rough or uneven surfaces, bending, stooping, working in confined space, and lifting or carrying moderately heavy (20-50 pounds) items and occasionally very heavy (100 pounds or over) items. Assists in the installation, operation, service, and repair of light commercial heat pump/air conditioning systems and other HVAC equipment such as refrigerators, fume hoods, window units, exhaust ventilators, coolers, deep freezers, and unit ventilators.