Industrial ventilation in East Africa is where worker safety, product quality and regulatory compliance meet. DOSHS inspections are tightening, international customers audit their suppliers’ factories, and insurers increasingly price risk on the state of a plant’s extract systems. Good ventilation design is cheaper than any of those conversations going badly.
Capture at source, always
The single most important principle: capture contaminants where they are generated, before they enter the worker’s breathing zone. A welding fume arm drawing 1,000 m³/h at the arc outperforms a roof fan moving ten times that volume from the ceiling. We design local exhaust ventilation — hoods, arms, slots and enclosures — around each process first, and treat general ventilation as the backup layer, not the primary control.
Design for the dust you actually have
Cement, grain, timber and steel dusts behave completely differently. Duct transport velocities must keep particles airborne (typically 18–23 m/s for heavy dusts); undersized ducts block, oversized ducts drop dust into settling layers that become fire and explosion hazards. Filter selection — cyclones, baghouses, cartridge units — follows from particle size and moisture, not from catalogue price.
Make-up air is not optional
Every cubic metre extracted must be replaced. Factories that install extract fans without make-up air paths end up with doors that slam, negative pressure that pulls contaminated air across clean areas, and extract performance a fraction of design. Balanced supply-and-extract design, with filtration on the supply side where product quality demands it, is what commissioning should verify and document.
Heat has to leave the building
Ovens, compressors, boilers and dense machinery routinely push factory floors 8–12°C above ambient. Stratification design — high-level extract, low-level cool air supply, roof ventilators sized to the actual heat load — keeps working conditions legal and productive without air-conditioning the entire volume.
Commission it, then maintain it
An extract system is only real when airflows are measured at every hood and balanced to design. We commission with calibrated instruments, hand over documented airflow schedules, and recommend annual re-verification — because fan belts slip, filters load and processes change. If your plant has never been measured, that is the first step toward both compliance and better working conditions.