Sos Commercial Services in downtown San Diego focuses exclusively on commercial refrigeration and HVAC, servicing restaurants, bars, and hospitality venues across the 92101 corridor and greater San Diego County. Walk-in cooler and walk-in freezer repairs — including evaporator fan motors, expansion valves, and defrost system diagnostics — share mechanical-room footprint with the structural and finish work Harper Construction Co. manages during restaurant buildouts and tenant improvements in the Gaslamp Quarter. The company installs and services reach-in refrigerators, ice machines, and commercial exhaust hood and ventilation systems, covering the full cold-side and airflow equipment chain for food-service operations. Condenser replacements on rooftop commercial AC units require high-voltage disconnect work and refrigerant recovery under EPA Section 608 regulations, an electrical scope the company coordinates with Ready Electric when a building's three-phase power supply needs load rebalancing after equipment upgrades. The most complex installations involve full commercial kitchen refrigeration buildouts — walk-in cooler and freezer construction, glycol beer-line chiller systems, and multi-zone exhaust ventilation — delivered turnkey for new restaurant openings in the Gaslamp Quarter and East Village.