Downdraft Paint Booth Installation for California Shops and Plants
A downdraft booth pulls clean air from a ceiling plenum straight down past the workpiece and out through grated floor exhaust. That vertical flow keeps overspray off the vehicle or part and away from the painter's breathing zone, which is why collision shops, aerospace maintenance hangars and fleet operations across California choose it when finish quality matters most. The catch is that the floor is part of the air system, so the building has to be ready for it.
Discuss your installationPit, Basement or Raised Platform
The first decision on any downdraft job is where the exhaust air goes once it passes the floor grates. A full-width or center pit cut into the slab gives a flush floor and drive-in access, but it means saw cutting, excavation, drainage review and new concrete. A raised basement booth sits on a steel platform with ramps, avoiding slab work at the cost of ramp length and lost ceiling height. In leased California buildings, owner approval for slab cutting often settles the question before engineering does.
- Flush pit: best access, most site work
- Raised basement: no slab cutting, needs ramp space and headroom
- Center trench: smaller cut, narrower exhaust path
Air Handling Above and Below
The ceiling plenum and intake filters spread incoming air evenly over the full booth length. Below the floor, exhaust filters capture what the grates collect before air reaches the fan and stack. We set the supply and exhaust fans so the booth runs slightly positive during spray, which keeps unfiltered shop air and dust from leaking in through door seals. Duct routing to the roof and stack height get coordinated with the roofer and any structural changes needed for the curb.
Collision, Aerospace and Fleet Workloads
A collision shop running several cars a day cares about bake cycle turnaround and door seals. An aerospace MRO line painting control surfaces or nacelle components cares about contamination and even airflow across tall parts. A fleet or municipal yard repainting service trucks needs length and door height. The booth shell may look similar, but plenum layout, lighting placement and the air make-up unit sizing follow the work, not the catalog.
Getting the Building Ready
Before steel arrives, the slab, power, gas and roof penetrations need a plan. We sequence pit work with the concrete contractor, set the booth, then bring in the electrician for panel and lighting connections and the gas fitter for the air make-up unit burner. Fire suppression and any detection devices are coordinated with that contractor so heads and nozzles land where the booth layout needs them.
- Slab drawings and any known utilities under the floor
- Available electrical service and panel locations
- Gas service size and meter location
- Roof construction and access for curbs and stacks
Planning a booth or oven project in California
Crews mobilize from Houston; California is roughly 1,350 miles away, so equipment, panels and tooling are staged and shipped ahead of the install crew.
Manufacturing in California is concentrated around Los Angeles, San Francisco Bay Area, San Diego, and Inland Empire (Riverside and San Bernardino). The sectors most likely to be specifying spray booths, blast rooms, powder systems and cure ovens there include aerospace, electronics, food and beverage equipment, and metal fabrication.
Mild temperatures keep heating loads modest; local air-quality districts tend to drive permitting, so exhaust and VOC controls are planned early.
Frequently asked questions
Can a downdraft booth go into a building without a pit?
Yes. A raised basement booth puts the exhaust plenum under a steel platform so no slab cutting is needed. You give up some height and need room for ramps, so measure door clearances and ceiling height before choosing it.
Why does a downdraft booth need an air make-up unit?
The booth exhausts a large volume of air during spray. Without matching replacement air, the booth and the building go negative, doors pull hard, and dirty air leaks in. The air make-up unit filters, heats and delivers that replacement air through the ceiling plenum.
Do you relocate existing downdraft booths?
We can disassemble, move and reinstall a downdraft booth. The pit or basement at the new site has to be built to match the old layout or modified, so bring the original drawings if you have them.
What slows a downdraft install down the most?
Floor work. Pit excavation, concrete cure time and any surprises under the slab drive the schedule more than setting the booth panels does.
How often should floor exhaust filters be changed?
It depends on paint volume and transfer efficiency. A manometer across the exhaust filters shows when pressure drop is climbing, and that reading should drive change-outs rather than the calendar.