Commercial & Industrial HVAC Projects — Hartzell’s Heat & Air
Hartzell’s has been doing complex mechanical work for 15+ years. These project case studies document some of the large-scope industrial and commercial HVAC work we’ve completed — from centrifugal chiller rebuilds at data centers to liquid refrigerant motor cooling on active oil and gas processing sites. Every project is documented, delivered on schedule, and backed by our master HVAC license.
Industrial HVAC · Chiller Service · Oil & Gas Facilities · Call 405-375-4822
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Project: McQuay Centrifugal Chiller Rebuild — Sprint Data Center, DFW
A Sprint data center in the DFW area experienced a chiller failure traced to a factory defect in the McQuay centrifugal compressor. The unit had to be completely torn down — compressor disassembled, rotor shaft and impeller wheel removed, defective components identified and replaced — and rebuilt to manufacturer specification before recommissioning.
The scale of this work required chain hoist rigging inside the plant room, precision measurement of all machined surfaces, factory-spec replacement parts, and a documented commissioning process. The chiller was successfully returned to full operation. For a data center, chiller downtime is measured in dollars per minute — this project required both technical depth and logistical execution.
Teardown — Finding the Factory Defect
Rebuild & Recommissioning
Project: Liquid Refrigerant Motor Cooling — Marathon Oil / Teco-Westinghouse, Omega & Coalton, OK
In a joint venture with Teco-Westinghouse, Hartzell’s designed and installed a compressorless liquid refrigerant pump cooling system at Marathon Oil’s natural gas processing facilities in Omega and Coalton, Oklahoma. The Teco-Westinghouse motors at these sites pump natural gas hundreds of miles through the pipeline to Houston — they run continuously and generate significant heat loads that require precise management.
The solution was Parker liquid cooling units circulating refrigerant through motor cooling jackets and back to remote heat exchangers — no compressor in the circuit, just a pump. Highly reliable and low-maintenance, well-suited to remote oil field operation. The project came in under budget and ahead of schedule.
Project: High-Efficiency Boiler Upgrade — Cornerstone Bank, Watonga, OK
Hartzell’s replaced an aging commercial boiler at Cornerstone Bank in Watonga, Oklahoma with a new Laars NeoTherm high-efficiency unit. The project involved full decommissioning of the original system, new venting and piping, and complete installation and startup of the replacement boiler.
Project: Custom 400-Ton Chiller Plant — Telecom Data Center
This project involved the design, build, and commissioning of a custom 400-ton chiller plant at a telecom data center facility. Unlike standard packaged equipment, this system was engineered and assembled to fit the specific cooling load and physical constraints of the facility — including a cooling tower installed in a purpose-built concrete equipment pit, custom-fabricated chilled water piping routed across the roof, and a hand-wired custom control panel built specifically for this system.
Telecom and data center facilities operate 24/7 with zero tolerance for cooling failures. The control panel was built from the ground up with relay logic, contactors, and fusing sized for this specific load — giving the facility operators a system designed for their exact requirements rather than a generic off-the-shelf solution. Preventive maintenance agreements (PMA) were established on commissioning to keep the system operating at design specifications long-term.
Project: Full Residential HVAC Replacement — Trane Heat Pump System
When your system has been running past its service life, you are not just paying for repairs — you are paying for a unit that is working harder every season to keep up. This homeowner was there: an aging Carrier system packed into a tight utility space alongside a water heater, limping through Oklahoma summers on borrowed time. We pulled it out, sized the replacement correctly with a Manual J load calculation, and put in a Trane heat pump system that will handle what this climate actually demands. Two outdoor units, properly matched indoor coils, a clean install. That is how a change-out should go.
What this project included: Full system removal and disposal, Manual J load calculation for proper sizing, Trane heat pump outdoor and indoor units, refrigerant line set, new thermostat, electrical whip, complete startup and commissioning.
Project: 20,000-Amp Battery Backup Build-Out & Raised Floor Precision Cooling
This project involved the HVAC build-out for a 20,000-amp DC battery backup facility at a telecom data center. Large battery string rooms generate significant and continuous heat loads — the batteries must be kept within a tight temperature range to maintain charge capacity and prevent thermal runaway. Overheating a DC plant is not an option.
The cooling solution was precision CRAC (Computer Room Air Conditioning) units combined with a raised floor cold air distribution system. Perforated floor tiles direct chilled air exactly where the battery strings generate heat — efficient, targeted, and scalable. This is a different discipline than residential or even standard commercial HVAC: precision cooling requires tight temperature and humidity tolerances maintained continuously, with no allowance for downtime.
Project: Copper-Clad Lightning Protection Grounding System — Data Center
This project required installing a copper-clad lightning protection grounding system at a telecom data center to a specification of 0.002 ohms ground resistance — an extremely tight requirement that only permanent molecular-bond connections can achieve and hold long-term. Standard commercial grounding requires 25 ohms or less. Critical facilities require 5 ohms. At 0.002 ohms, every connection and every electrode must be engineered precisely.
The copper-clad electrode plates and rods were bonded using exothermic (cadweld) welding — a process that uses a controlled thermite reaction to melt copper and flow it permanently around the joint, creating a molecular bond between conductors. Unlike mechanical connections that corrode and loosen over time, a properly executed cadweld connection is rated for the life of the facility. Every joint was tested to confirm the resistance specification before burial and backfill.
Why 0.002 ohms matters: At this resistance level, a lightning strike or power fault is dissipated into the earth almost instantaneously — protecting sensitive electronics, preventing ground potential rise, and keeping personnel safe. Achieving and verifying this spec requires precise electrode selection, proper soil preparation, and cadweld connections that won’t degrade. Mechanical connections simply cannot hold this specification over time.
Project: Large Cummins Generator Installation — Secured Data Center
Installing a large Cummins diesel generator at a secured data center is not a standard job. The facility operates 24/7 with no tolerance for power interruption — the generator is the last line of defense when utility power fails. Installation required coordinating a Grove crane to lift the generator enclosure over the security perimeter and set it precisely on a prepared concrete pad alongside the building, with workers guiding the unit from multiple positions during the lift.
Beyond the rigging, generator installation at this level involves fuel system connections, automatic transfer switch (ATS) integration, load bank testing, and coordination with the facility’s electrical team. The generator must transfer to load within seconds of a utility outage and sustain full facility power for an extended run. Getting this right the first time is not optional.
Project: 1,500 KW Generator PMA — Commercial Data Center
Retaining a preventive maintenance agreement on 1,500 KW commercial generator sets at a data center is not a matter of scheduling tune-ups. The contract required Hartzell’s to maintain four fully trained and certified technicians available around the clock — any one of whom could respond to this facility, know the equipment cold, and handle whatever they found. That’s an organizational commitment, not just a service call.
Preventive maintenance on generators of this scale covers fluid analysis, load bank testing, transfer switch exercise, cooling system inspection, fuel system integrity, battery condition, and full documentation for the facility’s compliance records. A generator that fails to start during a utility outage is worse than no generator at all — because someone signed off that it was ready.
On passing it down: Dave Hartzell has been bringing his daughter to job sites since she was old enough to wear a hard hat. She learned what 1,500 KW looks like before she finished junior high. That’s how a 35-year-old company stays technically sharp — the knowledge doesn’t just stay in a manual, it gets handed down in person, on the equipment, in the field.
Project: Commercial Generator PMA — Halon-Protected Critical Facility
Halon 1301 fire suppression is used in facilities where a conventional sprinkler system would destroy the equipment it was meant to protect — data centers, telecom switching centers, financial institutions, and government facilities. When you see that warning sign at a generator room entrance, you know the client operates at the highest level of criticality. Hartzell’s held the preventive maintenance agreement on this facility’s generator plant.
The generator room houses multiple Cummins units on containment pads with stainless exhaust and dedicated ventilation — a clean, well-engineered installation. The PMA covered regular load testing, fluid analysis, transfer switch exercise, fuel system checks, and full documentation. Entry requires hearing protection. The maintenance log stays current. The generators start when called.
Project: McQuay Air-Cooled Chiller Service — Halon 1301 Critical Data Center
Servicing a chiller plant at a Halon 1301–protected data center is a different level of responsibility. The McQuay ALS170 air-cooled water chiller — dual circuit, 325 lbs of R-22, three dedicated pump motors driving the chilled water loop — is what keeps that raised-floor data center at temperature. When it goes down, the facility’s cooling goes down. There is no acceptable window for a chiller outage in a mission-critical environment.
The Halon 1301 system in the suppression room tells you exactly what class of facility this is. Six cylinders on a red manifold, ready to discharge at the first sign of fire — protecting equipment that cannot tolerate water suppression. Working in this environment means following facility protocols, knowing exactly what you’re touching, and getting it right the first time. That’s what holding service contracts at these facilities requires.
Project: Large-Scale New Construction HVAC Install — Central Oklahoma
New construction means one chance to get the duct system right. On this large central Oklahoma build, Hartzell’s designed and installed a full custom sheet metal duct system — fabricated on-site, fitted to a spray foam attic envelope, and sized by Manual J load calculation. The two-man crew ran trunk mains the length of the building, cut and fit all branch takeoffs, and set the air handler and main plenum before drywall went up. Every connection sealed, every run supported — no flex duct shortcuts on a build like this.
Air handler and main plenum set before drywall
Two-man crew running trunk duct in spray-foam attic
Complete duct layout — trunk mains, branch boxes, all sheet metal
Trunk duct runs span the full building length
Making connections — every joint fitted and sealed
Branch duct takeoffs spaced along the trunk main
Project: Commercial Dehumidification System — Quest Multi-Unit Install, Oklahoma
Precision humidity control in a commercial indoor facility requires more than a standard HVAC system. This project involved ceiling-mounting multiple Quest commercial dehumidifiers, integrating them with the existing ductwork and circulation system, and balancing airflow across the full facility footprint. Quest units are purpose-built for high-latent-load environments — Hartzell’s supplied and installed the complete system to spec.
Multiple Quest dehumidifiers installed with ductwork integration — Hartzell’s Heat & Air
Why Industrial & Commercial Clients Choose Hartzell’s
- Documented project history — data centers, oil field, pipeline, commercial facilities
- Specialty system knowledge — centrifugal chillers, liquid refrigerant cooling, large boilers
- Project management capability — joint ventures, multi-phase projects, contractor coordination
- Master HVAC License + NATE certified — fully licensed for all mechanical work in Oklahoma
- On-time, under-budget track record — industrial clients can’t afford overruns
- Employee-owned for 15+ years — the same accountability, over 35 years
Frequently Asked Questions
Project: Geothermal Ground Loop & ClimateMaster System Installation
Geothermal is not complicated to install if you know what you are doing. It is complicated if you do not. Hartzell’s holds IGSHPA accreditation — one of very few shops in Oklahoma that do — because geothermal done wrong is not just inefficient, it is expensive to fix. This project involved both vertical boring and horizontal loop trenching depending on the lot layout, paired with a ClimateMaster GeoElite system inside. The ground loop was sized and grouted correctly. The unit was commissioned to specification. Oklahoma red clay does not make this easy. We have been doing it long enough that we know what it takes.
What this project included: Site evaluation and loop field design, vertical boring and/or horizontal trenching, loop pipe installation and grouting, ClimateMaster GeoElite system, loop connection and purging, full commissioning and documentation. Eligible for CKenergy, OG&E, and PSO utility rebates depending on service territory.
Project: 60-Ton Commercial Rooftop Unit System — Oklahoma Gas Processing Facility
Commercial rooftop units at 60 tons of capacity require the same discipline as any industrial installation — proper sizing, engineered ductwork, and a technician who has actually read the plans. This project at an Oklahoma natural gas processing facility involved multiple carrier rooftop units with custom sheet metal distribution, control panel integration, and full commissioning. Dave reviewed the engineering drawings on site before a single unit went up. That is not a formality. That is how you avoid a $60,000 mistake on a system that is expected to run without interruption.
What this project included: Engineering drawing review and field verification, Carrier commercial rooftop unit installation, custom sheet metal ductwork, control panel integration, full system commissioning and documentation.
Project: Industrial HVAC Service — Natural Gas Processing Facility, Oklahoma
Oil field and natural gas processing facilities are not forgiving environments. Cooling failures in a motor control room or a gas processing bay are not just an inconvenience — they are a production stoppage and a safety event. Hartzell’s has the industrial experience and the certifications to work in these environments. Hard hat on, work order in hand, following industrial safety protocols from the moment we pull on site. This is the kind of work most HVAC shops in Oklahoma simply do not do. We do it because we have the background, and because facilities like these need a company that takes documentation and safety as seriously as they do.
Capabilities demonstrated: Industrial HVAC service in hazardous environments, liquid refrigerant cooling system maintenance and repair, motor control room cooling, oil field safety protocols, complete service documentation.
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