General / dilution ventilation is moderate-temperature, continuous, often ATEX-rated extraction and supply: chemical plant halls, pharmaceutical production zones, food-processing facilities, electronics fabs, laboratories and workshops. Efficiency, reliability and hazardous-area scope are what matter — the fan runs 24×7 and rarely stops. We build process-ventilation fans from small in-line extraction at 5,000 CMH to hall systems beyond 1,00,000 CMH, across the full envelope below.
A process-ventilation fan manages general-purpose airflow: extracting from or supplying to a plant hall, cleanroom or process area, holding the room at its target pressure, and moving the air through filtration and ducting to or from atmosphere. What is in the air — and what is around the fan — sets the engineering.
Enough air for the hall air-change rate or hood face velocity — from 5,000 CMH in-line extraction to 1,00,000+ CMH hall ventilation.
The room at its target pressure — positive in a cleanroom, negative in an airlock and process room — across the whole system resistance of 100–1,000 mmWC (to 1,500 mmWC on high-resistance filtration).
What the air carries — solvent vapour, corrosive fume, or simply clean air at ambient to 80 °C (to 150 °C on warm-process duty) — for years without stopping.
What is in the air sets the materials, what is around the fan sets the ATEX scope, and the 8,760 hour/year run sets the efficiency and bearing life. Get all three right and the fan runs continuously for the design life. Get the metallurgy or the ATEX rating wrong, and it corrodes — or it cannot be installed at all.
Solvent vapour, food-fryer exhaust and chemical fume attack mild steel. Pick the casing for clean air and a corrosive-vapour stream eats the wetted surfaces within a season.
How we engineer it outMetallurgy matched to the gas: 316L SS or anti-corrosion coating for solvent vapour, 304 SS food-grade for fryer and dairy exhaust, duplex 2205 or PP-lined for aggressive chemical fume.
Solvent-handling, pharma granulation, alcohol-vapour and paint pre-treatment halls are flammable atmospheres. A sparking rotor or unbonded casing is an ignition source — and a non-ATEX fan cannot legally enter the zone.
How we engineer it outATEX Zone 2 build: aluminium impeller, bronze rub rings, bonded earthing, anti-static coatings and T-class temperature classification per the gas group. Self-declared Ex II 3G per 2014/34/EU Module A.
These fans never stop. A few points of efficiency lost over 8,760 hours a year is real money, and a bearing sized for intermittent duty fails early on a fan that cannot come offline.
How we engineer it outBackward-curved or airfoil wheel for peak efficiency on clean air, VFD control as default, and bearings rated L10h ≥ 40,000 h continuous with auto-lubrication where the fan is hard to reach.
We don't sell a catalogue near-fit. The fan is engineered to your air — composition, pressure cascade, ATEX zone and run hours — not a default selection.
No catalogue fan forced onto your spec. Your operating point is engineered onto the best-efficiency region of the selected wheel — because over a 24×7 duty, efficiency is the running cost — then verified on the 200 HP VFD test rig before dispatch.
| Parameter | Standard | On application |
|---|---|---|
| Volume flow | 5,000–1,50,000 CMH typical | up to 2,00,000 CMH on application |
| Static pressure | 100–1,000 mmWC | up to 1,500 mmWC for high-resistance filtration |
| Operating temperature | ambient to 80 °C | up to 150 °C for warm-process duty |
| ATEX classification | Zone 2 (Cat 3G) self-declared for solvent / flammable-vapour areas | Zone 1 (Cat 2G) via Notified Body |
| Drive power | up to 250 HP (most general/dilution-ventilation duty) | up to 400 HP on application |
| Speed | 600–1,800 RPM typical | per duty + sound limits |
| Balance quality | ISO 21940 G6.3 | G2.5 / G1.0 on application |
| Bearing life (design target) | L10h ≥ 40,000 h continuous | L10h ≥ 100,000 h on application |
The envelope above covers the great majority of process-ventilation duty. Sound is typically <85 dB(A) at 1 m for penthouse and rooftop locations, with <75 dB(A) available on a full acoustic package. For duty beyond this envelope — flow, pressure or temperature — we engineer to spec and quote on enquiry.
The same engineering language carries from your enquiry to the GA drawing to the nameplate — expressed in the standard AMCA conventions.
| Specification field | Options |
|---|---|
| Arrangement (AMCA 99) | Arr. 1 (overhung, fan bearings) / Arr. 4 (direct, motor on base) / Arr. 8 (overhung on common base) / Arr. 9 (overhung, motor side) / Arr. 10 (overhung, motor inside base) — selected by drive, access and installation. |
| Width / inlet | SWSI (single width, single inlet) default; DWDI (double width, double inlet) for high hall-ventilation flow at moderate pressure. |
| Wheel type | Airfoil or backward-curved (default, best efficiency on clean air) / radial-tipped (only where light dust carry-over from an upstream process occurs). |
| Class (by pressure / outlet velocity) | Class I / II / III selected from the duty point on the pressure-vs-outlet-velocity limits; higher class = heavier construction for higher pressure and tip speed. |
| Materials of construction | MS + epoxy (clean air) / 316L SS or anti-corrosion coating (solvent vapour) / 304 SS food-grade (fryer, dairy) / electropolished 316L (cleanroom, low-particle) / PP-lined, duplex 2205 or Hastelloy (aggressive chemical fume); aluminium impeller for ATEX. |
| Drive | Direct-coupled / V-belt / VFD (default for new installations and pressure-cascade control). Drive up to 400 HP across the envelope; speed typically 600–1,800 RPM. |
| Discharge & rotation (AMCA orientation) | Rotation CW or CCW (viewed from drive side) with discharge angle per AMCA — e.g. TH/BH/UB/DB — set to match your duct take-off and installed footprint. |
| Accessories & ATEX scope | VFD control; inlet/outlet flexible connectors; aluminium impeller, bronze rub rings, bonded earthing and anti-static coatings with T-class temperature classification for Zone 2; IP55/IP66 motor, outdoor coupling guard, corrosion-protected exterior and casing drain ports for rooftop units; auto-lubrication on hard-to-reach bearings; acoustic package on application. |
Every job's performance is verified at our works on the 200 HP VFD test rig, to the AMCA 210 / ISO 5801 method, before dispatch.
Cleanroom HVAC, granulation-hall ventilation, solvent-area extraction, dust-tight dispensing halls.
Process-hall ventilation, vent-gas extraction, laboratory fume-hood exhaust.
Production-hall ventilation, fryer exhaust, dairy spray-dryer area ventilation, oven ventilation.
Cleanroom HEPA-bank fans, fab makeup air, wet-bench exhaust.
Fume-hood exhaust, glovebox ventilation, BSL containment air.
Captive workshop ventilation, welding-shop exhaust, paint-preparation halls.
Pressure-cascade ventilation across cleanroom, airlock and process room.
45 application/duty types engineered. Tell us yours.
What our marks mean, in the words that survive an audit.
Tested to the AMCA 210 / ISO 5801 method, in-house on our 200 HP VFD rig. Tested-to-method — not AMCA-certified.
ISO 9001:2015 — third-party certified. Our only third-party certification.
Self-declared per 2006/42/EC + 2014/35/EU (Module A). A self-declaration, not a notified-body certificate.
Self-declared, Zone 2/22, Category 3, per 2014/34/EU, where the area classification calls for it.
Designed and built to API 673 as project-specific scope.
ASME Sec IX qualified welders + WPS for every joint.
ISO 21940 — G6.3 minimum, G2.5 / G1.0 on application.
ISO 20816 evaluation; ISO 14694 for fan-specific limits.
| Stage | Standard duty | API-673 / engineered |
|---|---|---|
| Offer / quotation | 3 working days — always | 7–10 working days |
| GA drawing for approval | 2–3 weeks from PO | 3–4 weeks from PO |
| Manufacture + balance + paint | 6–10 weeks | 10–14 weeks |
| Performance test + witnessed FAT | ~1 week | 1–2 weeks |
| Order-to-dispatch (total) | 9–14 weeks | 14–20 weeks |
Shutdown-driven replacements: we have shipped fans within 6 weeks of a clean PO. Tell us your shutdown window and we commit to a dated plan.
The same engineering, viewed three ways — by fan family, by duty, and by industry. Follow the cross-references.
No model numbers needed. Give us the operating conditions — flow, static, gas temperature, composition, particulate, and any tender standard — and our application engineers size the fan and quote it. Attach a spec or GA if you have one.
+91 90110 09155 · mihir.jitamitra@gmail.com