Commercial Variable Air Volume (VAV) Box Repair in Los Angeles

What we repair and optimize in VAV systems

We fix performance bottlenecks across single-duct, dual-duct, series, and parallel fan-powered VAV boxes. Whether your building faces hot/cold spots, hunting temperatures, noise complaints, or high energy bills, our engineers target the root cause—not just the symptom.

• Stuck or binding dampers, misaligned linkages, failed actuators (electric or pneumatic)
• Faulty or drifting temperature, pressure, and airflow sensors; recalibration and replacement
• Reheat coil issues (electric, hot-water): valves, relays, sequencers, safeties
• Fan-powered VAV problems: ECM/PSC motors, dirty wheels, belts, filters, noise and vibration
• Controller faults, lost tuning, improper sequences, network/BACnet mapping errors
• Insufficient or unstable static pressure from the AHU impacting VAV performance
• Pneumatic leaks, cracked tubing, inoperative thermostats and transducers

Our engineer-led diagnostic process

Precision comes first. We measure before we adjust. Our team uses calibrated instruments—air capture hoods, manometers, anemometers, data loggers, and thermal imaging—to benchmark flow, temperature, and pressure. We verify sequences of operation, confirm damper stroke and k-factor settings, and compare readings to design intent, ASHRAE guidelines, and California Title 24 requirements.

Control issues often look like mechanical failures. We review DDC/BMS trends, check PID loops, setpoints, and schedules, and test safeties and interlocks. When needed, we coordinate with the AHU/VFD to stabilize duct static pressure so each VAV box can modulate correctly. The result: faster recovery, tighter temperature control, quieter operation, and lower energy use.

Controls, DDC/BMS integration, and smart retrofits

From legacy pneumatic to modern DDC, we service and upgrade VAV controls to improve reliability and insight. Our factory training with Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China) shapes how we approach advanced control logic and airflow management in complex buildings.

• Controller replacement and reprogramming; sensor recalibration and addressing
• BACnet/Modbus integration and point mapping for trend logs and alarms
• ECM motor upgrades for fan-powered boxes; quiet, efficient operation
• Pneumatic-to-DDC conversions for precise modulation and remote visibility
• Sequence optimization for demand control ventilation and reheat efficiency

We document every change, provide as-found/as-left data, and coordinate with your facilities team so settings stay aligned with occupancy and use.

Testing, Adjusting, and Balancing (TAB) and compliance

Comfort and code compliance go hand in hand. After repairs, we balance VAV airflow and verify ventilation rates to support indoor air quality and energy goals. Our TAB process validates design cfm, minimums for ventilation, diversity strategies, and proper reheat control to prevent overcooling.

• Airflow verification at the diffuser and box level, plus duct static checks
• Minimum and maximum cfm setpoint validation for each zone
• Title 24 and ASHRAE 62.1 ventilation best practices
• Noise mitigation steps: motor isolation, damper tuning, and reheat staging

You receive a clear report with prioritized recommendations and cost/benefit notes so you can plan upgrades wisely.

Industries we serve

Office towers, medical and dental suites, schools and universities, retail and mixed-use, hospitality, light industrial, and specialized labs. We excel at large and complex projects where coordination, documentation, and commissioning make all the difference.

Service area and availability

Based in Los Angeles, we serve Los Angeles County and nearby Orange County, Ventura County, and Western Riverside County. Need to coordinate work after hours or on weekends to avoid tenant disruption? We offer flexible scheduling, rapid dispatch, and service windows tailored to your operations.

Why #1 AC Guys

• 4th-generation family of engineers with 80+ years in engineering
• Factory-trained by Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China)
• Engineer-led diagnostics, data-driven repairs, and documented results
• Expertise in complex controls, DDC/BMS, and multi-tenant balancing
• Transparent pricing, clean worksites, and safety-first practices
• Mission-driven: healthy air for a healthy life in every occupied space

Our goal is simple: restore comfort, stabilize operations, and cut waste—without shortcuts.

Get a fast quote and on-site assessment

Experiencing temperature swings, repeated BAS alarms, or persistent airflow complaints? Let’s diagnose the root cause and fix it right the first time. Contact #1 AC Guys for commercial Variable Air Volume (VAV) box repair in Los Angeles and surrounding counties. We’ll evaluate your VAVs, coordinate with your AHU and controls, and provide a clear, prioritized plan to get your building performing at its best.

Call now for a same-day or next-day visit, or send us your plans and trend logs for a quick engineering review. Healthy air, better comfort, lower costs—delivered by the team built for complex HVAC.