Commercial Ductwork Design, Installation and Repair
Duct design, fabrication and repair for businesses
A good rooftop unit can't fix a bad duct system. When an office has one conference room that's always hot, a storefront where the back of the space never cools, or a remodel that moved walls without moving the supply registers, the problem is usually the ductwork. We design, install, modify and repair commercial duct systems for tenant improvements, rooftop unit replacements and existing buildings where the airflow never worked right in the first place.
Why choose Blue Star
Duct problems are where we like to dig in. Our duct work starts with measuring airflow, not guessing, and we take photos of what we find so you can see the problem yourself. On tenant improvements we lay out supply and return to the new floor plan, and we can fabricate fittings in our own shop so the install fits the space. We also seal and insulate ducts to code, which keeps conditioned air in the rooms instead of leaking above the ceiling or on the roof.
- Airflow measured at registers
- TI layouts to the new plan
- Shop-fabricated fittings
- Sealed and insulated to code
- Rooftop curb transitions
- Photos of what we find
Where we work
Commercial duct work in our area often starts with a change of use. A Railroad Ave storefront in Pittsburg becomes a restaurant, a Concord office suite gets divided into smaller rooms, or a retail space on Lone Tree Way gets a tenant with different hours and loads. Older downtown buildings in Antioch's Rivertown and in Martinez often have ducts patched through several remodels. Ducts on hot East County roofs and in unconditioned spaces also need sealing and insulation that hold up through 100-degree summers.
Major corridors
- SR-4
- Railroad Ave
- A St
- Lone Tree Way
- Willow Pass Rd
- Alhambra Ave
- Ygnacio Valley Rd
We do this across our service area:
Each link opens that town's heating and air page.
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Read more reviewsColton was great. He found the problem right away and did a temporary fix to get my a/c running until he could get the right part ordered. He also made sure every inside was working well.
Questions we hear
Why does one part of our office stay hot while the rest is fine?
Usually because that area gets too little supply air for its load. Common causes are a disconnected or crushed duct above the ceiling, a branch that was undersized when the space was built out, a thermostat in the wrong room, or a remodel that added walls or people without changing the ducts. We measure airflow at the registers, find where the air is going, and quote a fix aimed at the actual cause.
What does HVAC work in a tenant improvement involve?
A TI usually means laying out new supply and return ducts for the new walls and rooms, relocating or adding diffusers, and sometimes adding zones or a second unit for spaces like a server room or conference room. The plans go through the city's plan check, and the work gets inspected before the ceiling closes. We work from the architect's drawings and coordinate with the general contractor's schedule.
Can you change ductwork when a rooftop unit is replaced?
Yes, and it is often the best time to do it. A new unit may have a different footprint or connection layout, so the curb transition and the first few feet of duct may need to change anyway. If the old system had airflow complaints, fixing them during the replacement costs less than coming back later, because the unit is already disconnected and the roof is already being worked.
Do commercial ducts need to be sealed and insulated?
Yes. California's Energy Code sets insulation and sealing requirements for ducts in unconditioned spaces and on roofs, and leaky ducts waste a surprising amount of conditioned air. In a building with a return air plenum above the ceiling, supply leaks can also short-circuit air straight back to the unit before it ever reaches the room. We seal joints with code-approved mastic or tape and insulate to the required level.
Can you install exposed ductwork in an open-ceiling space?
Yes. Restaurants, retail shops and creative offices often leave the ceiling open, and the ductwork becomes part of the look. Exposed spiral duct needs cleaner layouts, careful hanger spacing and sealed joints, since every run is visible. We plan routes with the designer or owner, and we can add insulation or use double-wall duct where condensation on cold duct surfaces could drip in summer.
Related services
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Have a room that never gets air, or a tenant space that needs a new layout? Call (925) 584-2428 and we will look at the duct system and quote the fix.