A cleanroom AHU fan drives filtered air through pre-, fine- and HEPA/ULPA banks to hold the pressure cascade and air-change rate that keep an ISO 14644 / GMP grade A–D space clean. This is filtered, clean air — the opposite of dirty-gas duty. The static is high across a loaded filter bank (600–1,200 mmWC across the AHU), the fan must never shed particles into the airstream, and it runs 24×7, so efficiency is the lifetime energy bill. We build cleanroom AHU fans across the envelope below — a plug / plenum wheel typically running 5,000 to 60,000 CMH per AHU.
A cleanroom AHU fan pushes filtered air through the filter bank of an air-handling unit: overcoming the high resistance of pre-, fine- and HEPA/ULPA filters, holding the room at its target pressure in the cascade, and delivering the air-change rate that keeps the space within its ISO 14644 class. The air is clean — so the fan itself is the last thing that can contaminate it.
Filtered air through the full filter-bank resistance — pre-, fine- and terminal HEPA/ULPA — typically 600–1,200 mmWC across a loaded AHU, and rising as the filters load.
The room at its target cascade pressure — positive in the cleanroom, stepped down through airlocks — typically +10 to +45 Pa between grades, steady as the filters load from clean to change-out.
Deliver the air-change rate the class needs — 20 to 60+ ACH — without shedding particles, fibres or oil mist into the airstream it is supposed to keep clean.
Clean air does not make the duty easy. The high static across the HEPA/ULPA bank has to be delivered at high efficiency because the AHU runs 8,760 hours a year; the fan must never contaminate the airstream; and the cascade pressure has to hold quietly as the filters load. A 30 HP AHU fan run several points below its best static efficiency wastes tens of MWh a year — and over the life of a facility that never switches off, the efficiency choice dwarfs the fan's purchase price.
The filter bank imposes 600–1,200 mmWC and the AHU runs 8,760 h/yr. A wheel that delivers that static a few points below its achievable efficiency burns money every hour it runs.
How we engineer it outHigh-efficiency backward-curved or airfoil wheel sized onto its best-efficiency point at the design static — high static efficiency as standard, higher on airfoil builds — with EC or VFD control to trim as filters load.
A painted-steel wheel, a crevice that traps and re-releases contamination, or a shedding coating puts particles into the exact airstream the AHU exists to keep clean — and fails the room's classification.
How we engineer it outHygienic, cleanable, crevice-free construction: SS304 / SS316 or cleanable epoxy, smooth-welded and ground, low-leakage casing, and an IP-rated washdown motor — nothing that sheds into the flow.
As filters load, the system resistance climbs — a fan sized without margin loses the cascade, and a noisy or vibrating unit is intolerable in an occupied grade A–D room.
How we engineer it outEC or VFD control holds the set-point as filters load; the wheel is balanced to ISO 21940 G2.5 for low vibration; and inlet/discharge silencers or an acoustic enclosure bring sound down for occupied space.
We don't sell a catalogue near-fit. The fan is engineered to your filter-bank static, cascade pressure, hygiene class 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 at the loaded-filter static — 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 | 5,000–60,000 CMH typical per AHU | up to 2,00,000 CMH on application |
| Static pressure | 600–1,200 mmWC across a loaded filter bank | up to 2,000 mmWC on application |
| Air temperature | ambient to 40 °C (conditioned supply air) | warmer on application |
| Static efficiency | high static efficiency as standard | higher on airfoil builds |
| Air-change rate served | 20–60+ ACH per the ISO 14644 class | higher on application |
| Sound level | <80 dB(A) @ 1 m | <72 dB(A) with silencers / acoustic enclosure |
| Balance quality | ISO 21940 G2.5 | G1.0 on application |
| Bearing life (design target) | L10h ≥ 40,000 h continuous | longer L10 on application |
The envelope above covers the great majority of cleanroom-AHU duty. Cleanroom AHU service sits low on flow and temperature and mid-to-high on static — the resistance is the loaded filter bank, not the gas. This is clean, filtered air, so no wear or dust package is needed; the engineering focus is hygienic construction, static efficiency and cascade stability. For duty beyond the envelope — flow, static or a hazardous solvent-handling area — we engineer to spec and quote on enquiry. Bearing life is a design target of L10h ≥ 40,000 h continuous, with longer L10 on application.
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) | Plug / plenum (unhoused) for direct AHU integration is the default; Arr. 4 (direct, motor on base) / Arr. 1 (overhung, fan bearings) / Arr. 9 (overhung, motor side) where a housed fan is specified — selected by drive, access and AHU layout. |
| Width / inlet | SWSI (single width, single inlet) default for cleanroom AHU duty; DWDI (double width, double inlet) for higher makeup-air flow at moderate static. |
| Wheel type | Backward-curved (default, best efficiency on clean air) / airfoil-bladed (highest-efficiency builds where the run hours justify it). No radial or high-solidity wheels — the air is clean, so efficiency wins. |
| 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 the higher filter-bank static and tip speed. |
| Materials of construction | SS304 or SS316 (hygienic, cleanable, crevice-free) / cleanable epoxy on steel where SS is not required — smooth-welded and ground, low-leakage casing. No wear or dust-abrasion package: the air is filtered and clean. |
| Drive | Direct-coupled / EC (small AHUs) / VFD (default for cascade-pressure and air-change control). IP55/IP66 washdown-duty motor; speed typically 900–1,800 RPM per duty and sound limit. |
| Discharge & rotation (AMCA orientation) | Plenum fans discharge into the AHU plenum (no scroll); for housed builds, rotation CW or CCW (viewed from drive side) with discharge angle per AMCA — e.g. TH/BH/UB/DB — set to match the AHU take-off and footprint. |
| Accessories & hygiene scope | Plug / plenum (unhoused) mounting; IE4 / VFD-rated washdown motor; flexible connection / expansion joint at the AHU take-off; inlet / discharge silencer and acoustic enclosure / sound hood for occupied space; special coating / paint (cleanable epoxy) or special material of construction (SS304/316); bearing isolators; vibration sensor / switch on critical units; drain and inspection access. |
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.
OSD, sterile and API cleanroom AHUs — grade A–D supply, HEPA-bank makeup air, pressure-cascade control across cleanroom, airlock and process room.
Fab and mini-environment recirculation, HEPA/ULPA bank fans, dry-room and assembly makeup air.
Hygienic packing and filling halls, aseptic-area supply air, controlled-environment AHUs with cleanable finish.
Hospital operating-theatre and isolation-room AHUs, laboratory supply air, controlled-environment plant rooms.
Controlled-area and containment AHUs, filtered supply air for classified and clean spaces.
Precision-manufacturing clean areas — controlled-particle supply air for coating, lithography and inspection lines.
Optics, medical-device and calibration cleanrooms — low-particle, low-vibration supply air held to class.
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