25-Ton Commercial AC Service in Rancho Cucamonga, CA
25-Ton Commercial AC Service in Rancho Cucamonga, CA
Rooftop Daikin-McQuay condenser + large indoor evaporator inspection
When Inland Empire heat is cranking, a big AC going down can halt operations fast. Our crew was called to a facility in Rancho Cucamonga, CA to evaluate a 25-ton commercial system serving a large open space. The system features a Daikin-McQuay air-cooled condensing section on the roof and a belt-driven, industrial evaporator/air handler inside a mechanical room.
The Call: Performance drop & preventive check
The site reported uneven cooling and wanted a full assessment before summer peak. We documented the installation (see photos) and performed a top-to-bottom inspection.
Rooftop: Daikin-McQuay Condenser Inspection
What we saw: Two top-mounted condenser fans, serviceable panels, and clear perimeter airflow—good rooftop housekeeping overall.
What we checked & did
♦ Lockout/Tagout and safety setup, then a full visual leak check on all braze joints and service valves.
♦ Verified fan rotation, blade condition, bearings, and measured motor amp draw against nameplate.
♦ Inspected electrical lugs, contactor faces, wiring insulation; snugged any loose terminations and confirmed proper strain relief.
♦ Cleared light debris from coil surfaces and shrouds; ensured unobstructed discharge (critical for head pressure control).
♦ Checked vibration, cabinet fasteners, and weather seals; tightened panels to prevent recirc and noise.
♦ Baseline operating data: head pressure, subcooling, ambient—to trend against future visits.
Indoors: Large Belt-Driven Evaporator / Air Handler
What we saw: A robust, older-generation air handler with large coil face, belt-and-sheave drive, and extensive hydronic/refrigeration piping.
What we checked & did
♦ Belt condition/tension and sheave alignment; adjusted tension to spec to protect bearings and restore airflow.
♦ Inspected blower bearings and shaft; confirmed smooth rotation and proper set-screw torque.
♦ Verified coil cleanliness and fin condition; cleared access and recommended a scheduled chemical clean during off-hours for best performance.
♦ Checked condensate pan & drain routing for pitch and blockages.
♦ Inspected control wiring and safeties; confirmed fan contactor health and cabinet grounds.
♦ Measured return/supply temperature split and reviewed static pressure to ensure the airside is within acceptable range for the coil/drive.
Findings & Corrections
♦ Mechanical: Minor hardware loosening from vibration (common on large tonnage). We tightened panel fasteners, electrical lugs, and fan guards to factory spec.
♦ Airside: Belt tension and alignment required correction; post-adjustment airflow and sound profile normalized.
♦ Condenser health: No active refrigerant leaks observed; fans operating correctly; coil face cleared of light debris to support proper condensing temperature.
♦ Controls: No nuisance faults; safeties functional.
Results
After adjustments and housekeeping:
♦ The system stabilized with consistent condenser fan operation and proper cabinet sealing.
♦ Air handler delivered stronger, smoother airflow thanks to corrected belt tension/alignment.
♦ Return/supply temperature split returned to spec, and the space began pulling down steadily.
We captured baseline readings so the facility can trend performance and catch small changes before they become big repairs.
Pro Tips for Large-Tonnage Systems
♦ Re-torque & re-tension: High-horsepower, belt-driven blowers shake hardware loose over time.
♦ Keep coils clean: A light rooftop rinse between deep cleans helps maintain head pressure in peak heat.
♦ Log data: Seasonal logs of subcooling/superheat, amps, and delta-T make future diagnostics faster and cheaper.
Serving Rancho Cucamonga & the Inland Empire
We service large commercial systems throughout Rancho Cucamonga, Ontario, Fontana, Riverside, Moreno Valley, and the greater Inland Empire—everything from 25-ton split systems to air-cooled chillers and industrial air handlers.
Need help with a big AC?
Fast diagnostics. Factory-level adjustments. Fewer surprises in peak season
EXTENSIVE SERVICE COVERAGE FOR COMMERCIAL HVAC & REFRIGERATION SOLUTIONS
No Commercial HVAC or Refrigeration job is too small or too far for us. While our primary branches are located in Palm Desert and Rancho Cucamonga, California, we’re dedicated to reaching customers wherever they are in need.
Proudly serving cities across California, including Indio, La Quinta, Indian Wells, Bermuda Dunes, Thousand Palms, Cathedral City, Rancho Mirage, Santa Ana, Fontana, Moreno Valley, Glendale, Ontario, Garden Grove, Palm Desert, Irvine, Anaheim, Riverside, Palm Springs, and extending to Los Angeles and beyond. Your satisfaction is our priority, no matter the distance or scale of the project.
AMERICAN COOL HEAT AIR BRANCHES
PALM DESERT, CA
77564 Country Club Dr. #142,
Palm Desert, CA, 92211
RANCHO CUCAMONGA, CA
10601 Civic center Dr 100H,
Rancho Cucamonga 91730