Commercial AHU (Air Handling Unit) Repair in Ontario, CA

Why Ontario Businesses Choose #1 AC Guys for AHU Repair

We are a 4th‑generation family of engineers with 80+ years of engineering experience, focused on delivering healthy air for healthy lives. Our team is factory‑trained by Fujitsu (Japan), Mitsubishi Electric (Thailand), Midea (China), Gree (China), and Haier (China). We also service AC PRO air handling units and AC PRO‑supplied components widely used across Southern California. For Ontario facilities, that means precise diagnostics, compliant repairs, and performance you can measure in airflow, comfort, and lower energy spend.

From rooftop packaged air handlers to custom built‑up systems, we repair mechanical, electrical, and controls issues end‑to‑end—so your building gets a complete fix, not a temporary patch.

What We Repair on Commercial Air Handlers

• Fans, motors, bearings, belts, pulleys, and vibration issues
• VFDs (variable frequency drives), starters, contactors, and overloads
• Coils (evaporator, chilled water, hot water), pan and drain rework, microbial growth remediation
• Filters, filter racks, bypass, and pressure drop optimization
• Economizers, dampers, actuators, linkages, and outdoor air intakes
• Sensors (temperature, humidity, CO2, pressure) and calibration
• Control boards, relays, BMS/EMS integration, and sequence corrections
• Leak detection, insulation, access panels, and casing/door integrity

Common Symptoms We Solve

• Hot/cold spots, poor ventilation, or rising CO2 levels
• High static pressure, short cycling, nuisance trips, or VFD faults
• Coil icing, musty odors, or visible dirt growth
• Uneven airflow after tenant improvements or layout changes
• Energy spikes and utility complaints
• Frequent filter clogging and IAQ concerns

Our Repair Process

1) Evaluate the space and the AHU together: we measure external static pressure, airflow, temperature split, and humidity to understand system behavior in real conditions.
2) Root‑cause diagnostics: from VFD parameters to damper sequencing and sensor drift, we isolate causes, not just symptoms.
3) Repair and recommission: we execute mechanical and controls repairs, then balance airflow, calibrate sensors, and verify economizer and safety sequences.
4) Document and handoff: you get clear reports with readings, photos, and recommendations to safeguard uptime and IAQ.

AC PRO Air Handlers—Serviced with Precision

Our engineers routinely repair AC PRO air handling units installed in offices, retail plazas, logistics hubs, and manufacturing spaces across Ontario and the Inland Empire. Whether the task is a coil restoration, VFD replacement, damper retrofit, or a controls cleanup, we follow engineering‑grade procedures so your AC PRO AHU returns to spec and stays that way.

Performance and IAQ Upgrades During Repair

• Coil deep cleaning and antimicrobial treatment to recover capacity
• Filter media optimization for lower pressure drop and better IAQ
• Economizer tuning for real savings under California climate conditions
• Fan alignment, belt tensioning, bearing service, and vibration reduction
• Sensor recalibration and control sequence verification for stable comfort

Engineered for Complex Projects

Have a large, multi‑zone, or mission‑critical site in Ontario? That’s our specialty. We handle complex airside problems—pressure imbalances, outside air compliance, heat load changes after build‑outs, and multi‑AHU coordination—with an engineering mindset. Expect fewer callbacks and longer service life.

Serving Ontario and Greater Los Angeles

We proudly serve Ontario, CA and the broader region: Los Angeles County and nearby areas including Orange County, Ventura County, and Western Riverside County. If you manage multiple properties, we can standardize diagnostics and reporting across your portfolio for consistent results.

When to Call #1 AC Guys

• Occupants report stuffy air, odors, or inconsistent temperatures
• Your BMS shows frequent alarms or unstable readings
• Utility bills rise without changes to operating hours
• Filters load quickly or coils re‑soil soon after cleaning
• After tenant improvements alter loads or airflow paths

Your Next Step

Get a commercial AHU repair that restores design airflow, comfort, and efficiency—without guesswork. Contact #1 AC Guys for expert service on AC PRO air handlers and complex airside systems in Ontario, CA. We’ll assess your system, provide a clear scope of work, and deliver repairs that last.