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 sample of units we've engineered, built and dispatched — each to a customer's duty point. Customer names and identifying marks are withheld. Click any photo to enlarge.
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 2,25,000 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 IS 4894 / ISO 5801 / AMCA 210 method, before dispatch.
The manufacturer’s cleanroom line is built for filter and fan units rather than for the main air handler — thirteen frames from Ø133 to Ø470 mm, all single-phase 220 VAC.
Thirteen frames, all 220 VAC single-phase, in a mix of plastic and aluminium-alloy impellers, including two ultra-thin frames for tight ceiling voids. Protection is not uniform across them — most are IP54 but several are IP44 and one is IP20, so it is a per-model check, not a line-wide one. The quietest frames run at 51 to 57 dB(A); the line as catalogued spans roughly 51 to 77 dB(A), each figure at its own stated duty.
A fixed-speed fan has to be set for the dirtiest the filters will ever be, and is throttled the rest of the time. A speed-controlled fan runs slow when the filters are clean and rises only as they load — and power follows roughly the cube of speed, so the hours spent slow are the hours that pay. On a cleanroom that runs continuously, most hours are clean-filter hours.
In an array, if one unit stops the remainder keep running and the unit continues at reduced capacity rather than stopping. Whether that reduced capacity still holds your room classification and your pressure cascade is a question about your qualified facility, and it is one we size for rather than assume — tell us the airflow you must hold with one unit down.
The honest boundary: these are ventilation fans for clean, filtered air. They are not for solvent-laden or overspray exhaust, classified areas, abrasive dust, or air hotter than the selected model’s own rating — which is stated per model, never across the range. Where the duty needs hygienic stainless construction, a washdown motor or a crevice-free weld, that is a fan we build ourselves; see the fan families.
One boundary, stated so procurement does not have to guess. The EC range is a distributed partner line for clean air only. Every conformity statement anywhere on this page — including the strapline in the footer below — describes fans Jitamitra manufactures in its own works. They do not extend to this range, and we make no CE or ATEX claim for it. Figures quoted here are the manufacturer’s published data, not independently verified by us, and nothing here is a warranty given on the manufacturer’s behalf.
More detail: the EC range · selecting an EC fan · EC fan control · retrofitting an AHU to EC
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 IS 4894 / ISO 5801 / AMCA 210 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. 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 14694 fan-specific limits; ISO 20816 general evaluation method.
| Stage | Standard duty | CE / ATEX / API / AMCA |
|---|---|---|
| Offer / quotation | 3 working days | 5 to 7 working days |
| GA drawing for approval | 3 days from customer PO | 5 to 7 days from customer PO |
| Manufacture + balance + paint | 2 to 3 weeks from PO + PI + approved GAD | 4 to 5 weeks from PO + PI + approved GAD |
| Performance test + witnessed FAT | ~1 week | ~1 week |
| Order-to-dispatch (total) | 4 to 6 weeks | 7 – 9 weeks |
Shutdown-driven replacements: we have shipped fans within 3 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.
Flow, static, gas temperature, application — or attach a spec, GA drawing or a multi-fan schedule. Engineer to engineer.
ISO 9001:2015 quality system · performance-tested to IS 4894 / ISO 5801 / AMCA 210 method · witnessed FAT on request, at no cost.
*For our standard range, additional days required for special projects
