Designing, fabricating, and installing the ductwork that moves conditioned air efficiently and quietly to where it is needed.
What We Provide
From shop drawings to sealed, insulated, balanced duct, here is how we handle air distribution on commercial jobs across Arizona.
Sealing & Insulation
A duct system is a pressure vessel. Every joint that is not sealed leaks — and in the desert, what it leaks is the most expensive air in the building.
Supply air leaves the air handler at roughly 55°F. In a Tucson summer it then travels through a ceiling plenum, an attic, or across a roof deck where the surrounding air can sit at 120–130°F for weeks while the outdoor design temperature pushes past 110°F. Every CFM that escapes through an unsealed joint is conditioned air the compressor produced and the space never received; every degree the air gains through thin or missing insulation is capacity gone before the first diffuser. Leakage on the return side is just as costly in reverse — a leaky return running through a hot attic pulls superheated, dusty air straight into the unit, and during monsoon season that means fine desert dust loading the filters and coating the coil.
That is why we treat sealing as part of the installation, not a punch-list item. Joints, longitudinal seams, and penetrations get sealed with mastic and approved tapes to the SMACNA seal class the pressure class calls for, and the energy codes adopted across Arizona require sealed duct on commercial work. Tight duct also protects the ventilation and indoor-air-quality design — outside-air quantities only mean something when the duct carrying them holds pressure.
Duct Design
Duct sizing is a three-way negotiation. Make a run smaller and the air moves faster: static pressure climbs, the fan works harder for every hour of its life, and the occupants hear the airflow at every diffuser. Make it larger and the noise disappears, but the duct costs more, weighs more, and competes for ceiling space with structure, piping, conduit, and lights. Good design lands in the band where mains and branches carry their airflow at velocities the space can live with, the total static stays inside what the air handler or rooftop unit can actually deliver, and the duct still fits above the ceiling with room to service it.
Getting it wrong is expensive in both directions. An undersized trunk starves the diffusers at the end of the run no matter how hard the balancer fights it, and oversized duct wastes sheet metal and forces soffits nobody budgeted. Because our HVAC and electrical crews plan the same ceiling together, the duct gets sized for the airflow and routed once — not resized after a clash.
Where It Applies
Ductwork takes our Tucson crews into office tenant improvements, retail buildouts, and warehouse and industrial space.
Testing, Adjusting & Balancing
Installed duct is a claim; a balance report is the evidence. Testing, adjusting, and balancing (TAB) measures the airflow at every diffuser and return against the design values, records fan speeds, motor amps, and static pressures, and documents the damper positions that produced the result. A system that has been balanced delivers design air to the corner office and the back storeroom alike. A system that has not is running on hope — and the comfort complaints, hot rooms, and doors that whistle shut are how the building tells you.
Balancing matters doubly in the desert. Buildings here are proportioned to hold slight positive pressure so that hot, dusty outside air infiltrates as little as possible — during a monsoon dust storm, that pressurization is the difference between a clean lobby and grit under every door. We coordinate TAB before turnover on our own work, and we tell every owner the same thing: make the balance report a closeout deliverable on any commercial HVAC project, and keep it. It is the baseline every future service call gets measured against.
Life Safety
Every place a duct penetrates a fire-rated wall, floor, or shaft enclosure, the rating has to be preserved — that is the fire damper's job, closing on its fusible link or actuator so fire cannot ride the ductwork through the barrier. Smoke dampers do the same at smoke barriers, driven by detection and the alarm sequence, and combination fire/smoke dampers cover the walls where both ratings meet. Which walls are rated — corridors, demising walls, shafts, occupancy separations — comes off the code plan, which is exactly why damper locations should be settled during design rather than discovered at inspection.
Two details separate a clean inspection from a callback. First, every damper needs an access door sized and placed so a person can actually reach it — a damper buried above a hard-lid ceiling with no access fails before it is ever tested. Second, dampers carry an inspection life: NFPA 80 and NFPA 105 require an operational test at installation, again one year later, and then every four years for most occupancies — six for hospitals. We install dampers with their access panels planned, tagged, and reachable, so the building passes its first inspection and its fifteenth.
The Design-Build Advantage
Duct, piping, and conduit all want the same ceiling space. Because our HVAC and electrical crews coordinate inside one company, the rough-in gets resolved in the field once — not re-routed after a clash.
Back to HVACTenant Improvements
In a tenant improvement, the existing ductwork is either an asset or a liability, and it pays to know which before the walls move. Trunk duct that is sound, sized for the new loads, and roughly aligned with the new floor plan can usually stay — we rework the branches, replace tired flex, and set new diffusers to the new ceiling grid. That protects both cost and schedule, and it is the first thing we look for when we walk a space.
Reuse stops making sense when the new use changes the math. An office converting to a restaurant, clinic, or fitness space carries very different loads and outside-air requirements than the duct was sized for. Deteriorated interior lining, crushed or water-damaged runs, and decades of accumulated desert dust argue for replacement. And when the new plan adds rated walls, existing duct suddenly penetrates barriers that now require fire or smoke dampers where none exist. We give owners a straight answer run by run — keep, rework, or replace — and either way the finished system gets rebalanced, because a layout balanced for the old floor plan is out of balance for the new one by definition. It is the same walk-through we do on the electrical side of a tenant improvement, and on design-build TIs one team answers for both — see the full HVAC scope.
FAQ
More than almost any other single defect. Supply air leaves the unit at roughly 55°F, and in a Tucson summer it often travels through a ceiling plenum, attic, or roof deck sitting at 120–130°F. Every cubic foot that escapes before reaching a diffuser is cooling you paid for and never received — and industry testing routinely finds unsealed systems leaking 10–25% of their airflow. Sealing the duct system is usually the cheapest cooling capacity you can buy back.
SMACNA — the sheet-metal industry's standards body — defines duct seal classes A, B, and C. Class C seals transverse joints only; Class B adds longitudinal seams; Class A seals joints, seams, and every wall penetration. The energy codes adopted across Arizona effectively require sealed duct on commercial work, and higher-pressure systems warrant the higher class. We seal with mastic and approved tapes as part of installation, not as a punch-list item.
Yes. Testing, adjusting, and balancing (TAB) is the measured proof that a duct system delivers its design airflow. The report documents airflow at every diffuser against the design values, fan speeds and motor amps, and system static pressures. Without it, nobody actually knows whether the far offices get their air. We coordinate balancing before turnover, and we recommend every owner make the balance report a closeout requirement on any commercial HVAC project.
Fire dampers are required where ducts penetrate fire-rated walls, floors, and shaft enclosures; smoke dampers protect smoke barriers; combination fire/smoke dampers serve where the two ratings overlap. Every damper needs an access door so it can be tested and reset, and NFPA 80 and NFPA 105 require an operational test at installation, again one year later, then every four years for most buildings — six for hospitals.
Often, partially. Sound, well-sized trunk duct that fits the new layout can usually stay, with new branches, flex, and diffusers matched to the new ceiling plan. Duct usually cannot stay when the new use changes the loads — office to restaurant or fitness, for example — when interior lining has deteriorated, when the runs are damaged or dust-loaded, or when new rated walls put duct penetrations where dampers now have to go. Either way, the reconfigured system needs to be rebalanced before opening day.
Usually velocity. Undersized duct forces air to move faster, and the rush you hear at the diffusers is static pressure being wasted as noise. Balancing dampers slammed nearly shut right behind a diffuser make it worse. The fixes range from rebalancing at the branch instead of the outlet, to resizing a run, to swapping diffusers for a quieter throw pattern — the diagnosis is quick, and it is usually simpler than living with it.
It depends on the pressure class and gauge of the duct, the linear footage and fitting count, insulation requirements, how congested the ceiling space is, whether the work happens in an occupied building, and how many fire and smoke dampers the wall ratings require. Rather than quote a number that will be wrong in both directions, send us the mechanical drawings — we will come back with a firm bid and fabrication lead times.
Send the mechanical drawings. We'll come back with fabrication lead times and an installation plan that fits the schedule.
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