Commercial Variable Air Volume (VAV) Box Repair in Fullerton

As a family‑owned, fourth‑generation engineering company, #1 AC Guys delivers precise, standards‑driven VAV box repair for offices, retail, healthcare, education, and industrial facilities in Fullerton. Our mission is healthy air for healthy lives—and in commercial buildings, that starts with reliable, balanced airflow at every zone.

What We Repair and Optimize

• Actuators and dampers: sticking, misaligned, or failed components
• Thermistors, pressure sensors, and airflow sensors: calibration and replacement
• Controllers and DDC: programming errors, communication issues, resets
• Pressure‑independent VAV boxes: flow sensor verification, K‑factor validation
• Reheat coils: electric and hot water valve control, staging, and safety checks
• Noise and comfort issues: high velocity, turbulence, and diffuser mismatch
• Airflow balancing: zone CFM targets, diversity, and static pressure stability

We address the whole system—box mechanics, controls logic, and upstream supply variables—so your fix holds under real operating conditions.

Our VAV Repair Process

• Discovery and diagnostics: interview operations staff, review trends, and perform live tests
• Functional testing: verify actuator stroke, damper response, and sensor accuracy
• Controls and sequence tuning: align with your BAS and intended sequences of operation
• Mechanical corrections: repair or replace failed actuators, linkages, sensors, and valves
• Commissioning: recalibrate CFM, confirm setpoints, and validate alarms
• Report and handoff: provide data, photos, and practical guidance for operations

Where required, we coordinate with your building automation vendor to ensure seamless integration and change management.

Engineering Depth that Shows in the Results

With 80+ years of engineering experience and factory training at Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China), our team brings repeatable methods to complex VAV environments. Expect fewer comfort complaints, lower energy use, more stable static pressure, and cleaner indoor air supported by correct ventilation rates.

Common Symptoms We Solve

• Hot and cold spots across floors or at perimeter zones
• Boxes stuck at minimum or maximum flow; rooms starved for air
• Short cycling AHUs due to unstable static pressure
• High noise at diffusers from excessive velocity
• Reheat not modulating; humidity or temperature drift
• BAS trend logs showing oscillation or hunting

We fix root causes and provide clear documentation so your facilities team knows exactly what changed and why.

Code, Comfort, and Cost

Our repairs aim at three targets: compliance with California Title 24 intent, measurable comfort improvements, and total cost reduction. From re‑establishing correct minimum ventilation to tightening control sequences that prevent simultaneous heating and cooling, we tune boxes to support both IAQ and efficiency.

Industries We Serve in Fullerton

• Corporate offices and campuses
• Retail and mixed‑use properties
• Healthcare clinics and medical office buildings
• Schools, universities, and labs
• Manufacturing and light industrial
• Hospitality and entertainment

We are equipped for large, multi‑zone facilities and challenging retrofits—exactly where our engineering background delivers the most value.

Service Area

Headquartered in Los Angeles, we proudly serve Fullerton and the surrounding communities of Orange County, as well as Los Angeles County, Ventura County, and Western Riverside County. If you operate multiple sites across these regions, we can standardize VAV repair and commissioning procedures for consistent outcomes.

Preventive Care and Retro‑Commissioning

Beyond urgent repairs, we offer planned maintenance and retro‑commissioning for VAV systems. Routine functional testing, sensor calibration, and sequence verification keep boxes on spec and extend equipment life. Even minor drift in sensors or linkages can erode comfort and drive energy waste—proactive attention stops that early.

Why Choose #1 AC Guys

• Fourth‑generation family business with 80+ years of engineering expertise
• Factory‑trained at Fujitsu, Mitsubishi Electric, Midea, Gree, and Haier
• Data‑driven diagnostics, clear reporting, and careful commissioning
• Specialists in large and complex commercial projects
• Mission‑focused on healthy indoor air and reliable comfort

From the first call to final sign‑off, you get senior‑level attention and solutions that stand up to real‑world loads.

Get Started Today

Experiencing VAV issues in your Fullerton building? Contact #1 AC Guys for a professional assessment and a practical plan that restores comfort, stabilizes airflow, and aligns your system with best‑practice operation. We will schedule quickly, communicate clearly, and deliver results you can measure in better IAQ and lower operating costs.

Healthy air, engineered right—this is our promise to every client we serve.