Commercial HVAC & Ventilation Systems
From RTUs to AHUs and VAV systems, we keep airflow, temperature, humidity, and building pressure under control—supporting healthcare compliance, hospitality IAQ and pressure control, and industrial airflow requirements across Oklahoma.
Commercial HVAC Services in Oklahoma
Total Mechanical Services provides commercial HVAC repair, maintenance, and installation across Oklahoma City, Tulsa, and statewide. We specialize in RTUs, MAUs, AHUs, and VAV systems—supporting facilities where airflow and pressure are operational issues, not comfort complaints. We work with Facility Managers and Procurement teams and can support vendor onboarding with compliance-minded documentation. Commercial and industrial facilities only.
Service Highlights
- Rooftop Units (RTU)
- Make-Up Air Units
- VAV Systems
- Air Handling Units
What HVAC Systems Do We Service?
Complete lifecycle support for commercial air systems—from packaged rooftop units to complex central plant air handling.
Rooftop Units (RTUs)
Packaged Cooling & Heating
Self-contained packaged units that provide heating, cooling, and ventilation from a single rooftop installation. Common in retail, office buildings, and light industrial applications.
- Compressor and condenser repairs
- Economizer setup and repair
- Belt and bearing replacement
- Hail damage assessment and repair
Make-Up Air Units (MAUs)
Kitchen & Industrial Ventilation
Supply 100% outside air to replace exhaust from kitchen hoods, paint booths, and industrial processes. Critical for maintaining building pressure balance and NFPA 96 compliance.
- Gas-fired burner tuning
- Airflow balancing with exhaust hoods
- Filter systems and UV treatment
- Direct-fired and indirect-fired units
Air Handling Units (AHUs)
Central Plant Air Distribution
Large indoor units that condition and distribute air through ductwork. Connected to central chilled water or steam systems for heating and cooling. Common in hospitals and large commercial buildings.
- Coil cleaning and replacement
- VFD motor upgrades
- Damper actuator repair
- Humidifier integration
VAV Systems
Zone Temperature Control
Variable Air Volume systems modulate airflow to individual zones based on thermostat demand. Provides precise temperature control and energy savings in multi-zone buildings.
- VAV box calibration and repair
- Pneumatic-to-DDC conversions
- Reheat coil service
- Airflow balancing and TAB
Complete HVAC Services
From emergency repairs to complete system replacements, our factory-trained technicians handle every aspect of commercial HVAC service.
Brands We Service
Plus Aaon, McQuay, and legacy equipment from discontinued manufacturers.
Critical Environment Applications
Commercial HVAC goes far beyond comfort cooling. We engineer solutions for environments where air quality is mission-critical.
Healthcare Facilities
Operating room pressure control, isolation room ventilation, and HEPA filtration for infection control. Meeting Joint Commission and ASHRAE 170 requirements.
- • Positive/negative pressure rooms
- • ACH (air changes per hour) verification
- • ICRA containment during service
Hotels & Hospitality
Quiet operation, humidity control, and pressure management to reduce guest complaints and keep rooms, corridors, and common areas stable during peak occupancy.
- • Humidity control and musty-odor reduction
- • Corridor pressurization and odor containment
- • Noise troubleshooting and vibration isolation
Manufacturing & Warehouses
Industrial ventilation for welding fumes, paint booths, and process exhaust. Evaporative cooling for large warehouse spaces and worker comfort.
- • Exhaust capture systems
- • Evaporative cooler service
- • Destratification fans
Engineered for Oklahoma Weather
Oklahoma's extreme weather—from 105°F summers to sub-zero ice storms—creates unique challenges that out-of-state contractors don't understand.
Hail & Storm Damage
Rooftop units are exposed to Oklahoma's severe storms. We assess hail damage to coils, cabinets, and electrical components—and coordinate with your insurance.
High Ambient Performance
When temps exceed 100°F, air-cooled systems lose efficiency. We ensure coils are clean and refrigerant charges are optimized for peak summer performance.
Winterization
Frozen coils and burst condensate lines are preventable. Our fall preparation protocols protect your RTUs from Oklahoma ice storms.
Oklahoma Service Area
Frequently Asked Questions
Common questions from Oklahoma facility managers about commercial HVAC service.
Why does my building have negative pressure (doors hard to open)?
Negative building pressure typically indicates an imbalance between exhaust and supply air. Common causes include make-up air units not running, exhaust fans operating without adequate return air, or outside-air dampers stuck in the wrong position. In hotels and other multi-zone buildings, corridor pressurization issues can also drive odor migration and slamming doors. Our technicians perform airflow and pressure measurements to identify the source and balance the system—eliminating door issues and uncomfortable drafts.
How often should commercial HVAC filters be changed?
Standard commercial filters (MERV 8-11) should be checked monthly and changed quarterly at minimum. In Oklahoma, where dust and pollen loads are heavy, many facilities benefit from monthly changes during peak seasons. Healthcare facilities with higher MERV ratings (13+) or HEPA filters require strict adherence to manufacturer schedules. Neglected filters increase static pressure, reduce airflow, and cause premature motor and compressor wear.
What is an economizer and why does it matter?
An economizer is a damper system that brings in outdoor air for "free cooling" when conditions are favorable—typically during Oklahoma's mild spring and fall months. A properly functioning economizer can significantly reduce cooling costs. However, stuck dampers, failed actuators, or miscalibrated sensors can cause the economizer to bring in hot humid air during summer (wasting energy) or fail to utilize free cooling when available. Annual economizer testing is essential for energy efficiency.
Should I repair or replace my aging RTU?
The typical commercial RTU lifespan is 15-20 years. However, the repair-vs-replace decision depends on multiple factors: repair cost relative to replacement value (the "50% rule"), refrigerant type (R-22 units face escalating costs), energy efficiency improvements in new equipment, and Oklahoma utility rebates. We can perform a comprehensive assessment including efficiency testing, repair history review, and ROI analysis for replacement options. Modern high-efficiency units often pay for themselves through energy savings within 5-7 years.
HVAC Resources & Case Studies
View All Resources
Protecting Commercial HVAC From Oklahoma Heat Domes: High-Ambient Strategy, Coil Cleaning, and Load Management
A practical Oklahoma guide to surviving heat domes: high-ambient chiller/RTU performance, coil cleaning cadence, tower readiness, demand management, and emergency cooling planning.

RTU Winterization Checklist for Oklahoma Ice Storms: Freeze Protection, Hail Risk, and Start-Up
A practical rooftop unit winterization checklist for Oklahoma facilities: freeze protection, condensate and economizer checks, hail prep, and post-storm start-up steps.

Data Center Cooling Best Practices in Oklahoma: CRAC/CRAH, Hot Spots, Humidity, and Redundancy
A practical Oklahoma guide to data center cooling: how to prevent hot spots, manage humidity, maintain CRAC/CRAH systems, and build redundancy that holds up during heat events.
Keep Your Building Running
From emergency RTU repairs to complete system retrofits, our factory-trained technicians are ready. Commercial and industrial inquiries only.
Serving Oklahoma City, Tulsa, and Statewide Since 2008