Since 1978, Aerco Systems LLC on Santee's Prospect Avenue has provided portable HVAC equipment rentals for commercial and industrial facilities across San Diego, Orange, and Riverside counties. The rental fleet includes chillers, cooling towers, air handlers, fans, package units, and pumps that supplement permanent systems during planned shutdowns, allowing resident contractors including Schoonmaker Heating & Air Conditioning on Prospect Avenue to complete installations without disrupting building occupancy. Emergency mobilization delivers temporary chiller units to commercial sites within hours of a system failure call, covering everything from server-room cooling to event-venue climate control. Rooftop equipment staging on commercial structures coordinates with contractors such as AVL Roofing on Buena Vista Avenue for crane-access clearance and roof-load assessment. Equipment specifications range from 1-ton portable spot coolers for single-room applications to 500-ton trailer-mounted chiller plants with variable-frequency-drive compressors for campus-wide temporary cooling.