Commercial HVAC & Mechanical Services in Selma, TX

J3 Mechanical Services helps commercial and industrial facilities across South Texas stay comfortable, efficient, and fully operational. From fast repairs to full system replacements and ground-up mechanical construction, we bring decades of proven expertise to every job.

Commercial Excellence

Complex systems, critical environments

Trusted Service

24/7 emergency response

Modern Innovation

BAS + high-efficiency upgrades

Partnership Approach

Maintenance contracts built for uptime

Rapid diagnostics & restoration

Prevent breakdowns & preserve assets

Right-sized, code-compliant systems

Design-build & full mechanical scope

Our Mechanical & HVAC Services

Complete coverage for your equipment lifecycle and project needs.

Preventative Maintenance AC Services Chillers Cooling Towers Boilers VRF / VRV Building Automation Retrofit Construction Ground-Up Tenant Build-Out Ductwork Design-Build Project Engineering / VE Rental Chillers / HVAC

Preventative Maintenance Plans

Tailored commercial maintenance programs built to reduce downtime and extend equipment life. We inspect, clean, test, and track performance so small issues don’t turn into major failures— improving reliability, energy efficiency, and budget predictability.

AC Services & Replacement

Full-cycle commercial air conditioning support—repairs, airflow correction, component replacement, and performance optimization. When systems age out, we design and install high-efficiency replacements matched to your building’s load and operating profile.

Chiller Services & Replacement

Specialized service for air-cooled and water-cooled chillers, pumps, valves, and controls. From tube cleaning and leak detection to major repairs and full change-outs, we keep chilled-water plants running at peak output.

Cooling Tower Services & Replacement

Cleaning, basin restoration, fan/motor repair, scale and corrosion mitigation, and tower replacement. We verify approach temperatures and system performance to protect heat-rejection capacity and total plant health.

Boiler Services & Replacement

Safe, precise service for hot-water and steam boilers—burners, heat exchangers, pumps, venting, and safety controls. We also design and install efficient replacements that reduce risk and operating cost.

VRF / VRV Systems

Installation, troubleshooting, refrigerant management, and controls integration for VRF/VRV equipment. We ensure proper zoning performance, efficiency, and system longevity across multi-space facilities.

Building Automation

BAS installation and service for central monitoring, scheduling, diagnostics, and energy optimization. We integrate sensors, VFDs, and control points across chillers, boilers, RTUs, and auxiliary systems.

Retrofit Projects

Smart upgrades without full rebuilds—equipment swaps, phased replacements, duct re-design, and control modernization. Perfect for improving performance while minimizing downtime.

Construction – Ground Up

Turnkey mechanical scope for new builds: planning, scheduling, installation, controls, commissioning, and final turnover. We coordinate with GCs to keep projects moving and inspections clean.

Tenant Build-Out / Remodeling / Renovation

Fast, coordinated HVAC redesigns for new layouts and leased spaces—system expansions, relocations, code updates, and occupied-building work executed with minimal disruption.

Ductwork Installation

Custom duct fabrication and installation with proper static pressure, sealing, insulation, and final balancing—delivering reliable airflow, comfort, and indoor air quality.

Design-Build Construction

One partner from concept to commissioning. We manage engineering, equipment selection, permitting support, installation, and startup under one roof for tighter budgets and timelines.

Project Engineering / Value Engineering (VE)

Lifecycle-driven engineering support that protects performance while controlling cost. We evaluate system options, ROI, phasing, and constructability to deliver the best-fit solution.

Rental Chillers / HVAC Units

Temporary chillers and HVAC units for emergencies, planned shutdowns, capacity shortfalls, or construction phases. We deliver, connect, and maintain the rental system to keep you operational.