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Wilhelmina Castellanos-Oduya

Commercial HVAC Service Technician
Denver, CO, United States

Professional Summary

Commercial HVAC service technician with 9+ years of experience maintaining and repairing commercial and light-industrial HVAC-R systems across the Denver metro, including rooftop units, VRF/VRV systems, air-cooled chillers, boilers, and building automation controls. EPA 608 Universal certified and NATE certified in Commercial Air Conditioning & Heat Pump, with hands-on expertise in BACnet/Niagara BAS integration, combustion analysis, and refrigerant recovery. Proven record of cutting repeat callbacks, extending equipment life, and keeping facilities running through planned preventive maintenance and fast diagnostic response.

Employment History

Lead Commercial HVAC Service Technician
Front Range Mechanical Services · Denver, CO
Mar, 2021 · Present
Lead a 4-technician service crew across 60+ commercial sites, dispatching via ServiceTitan and averaging 22 completed service calls per week with a 96% first-visit fix rate. Diagnose and repair rooftop units, VRF/VRV systems, air-cooled chillers, and boilers, cutting repeat callbacks by 34% through root-cause troubleshooting and combustion analysis. Program and tune BACnet and Niagara building automation systems for 18 sites, reducing unplanned HVAC downtime by 27% and trimming seasonal energy costs by roughly $84,000 annually. Build and execute quarterly preventive-maintenance programs covering 400+ pieces of equipment, extending average equipment life by 4 years and mentoring 6 junior technicians with zero recordable incidents in 2024-2025.
HVAC-R Service Technician
Peak Climate Solutions · Aurora, CO
Jun, 2017 · Feb, 2021
Serviced 300+ light-industrial and retail locations, completing an average of 18 service calls per day with a 94% same-week resolution rate. Recovered, evacuated, and recharged refrigerants to EPA 608 standards on 150+ systems annually while maintaining accurate documentation and zero violations. Replaced failed compressors, motors, and control boards on packaged and split systems, cutting average repair turnaround time by 25%. Tuned BAS schedules and setpoints for 12 retail sites, lowering summer cooling costs by 16% during peak-rate periods, and earned NATE Commercial AC & Heat Pump certification in 2019.
HVAC Installer / Apprentice
Mile High Heating & Air · Lakewood, CO
Aug, 2015 · May, 2017
Installed and commissioned 70+ residential and light-commercial systems, including furnaces, condensers, and ductwork, all passing first inspection. Assisted lead technicians with duct sizing, line-set brazing, and electrical connections, reducing average install time by 15%. Charged and tested systems to manufacturer specifications, achieving a 98% first-year no-return rate on installed equipment. Completed Emily Griffith Technical College HVAC-R coursework while working full time and earned EPA 608 Universal certification in 2015.

Education

Associate of Applied Science, HVAC-R Technology
Emily Griffith Technical College · Denver, CO
2015

Skills

Commercial rooftop units
Split systems
VRF/VRV systems
Chillers & boilers
BACnet/Niagara BAS controls
Refrigerant recovery
Combustion analysis
Preventive maintenance programs
ServiceTitan
Customer communication

Languages

English · fluent
Spanish · fluent

Courses

EPA 608 Universal Certification
US EPA · 2015
NATE — Commercial Air Conditioning & Heat Pump
North American Technician Excellence · 2019
OSHA 30 Hour General Industry
OSHA Training Institute · 2020
Colorado Journeyman Mechanical License
Colorado DPO · 2021
Trane / Daikin VRF Factory Training
Trane & Daikin · 2022