Fan Filter Unit Selection

The component that decides a cleanroom’s classification, its energy bill and its noise — and the one most often chosen on unit price.

  • 2,806products across this application
  • 841verified manufacturers
  • 5equipment groups

WhatThe building block of modular cleanrooms

A fan filter unit combines a fan, a HEPA or ULPA filter and its controls in one ceiling module. Fitting them across a ceiling grid produces the air change rate a classification requires without a central air handling plant and its ductwork. Modern units carry EC motors with speed control and, on better designs, closed-loop constant-volume control.

WhoWho buys it

Cleanroom construction companies, pharmaceutical and electronics manufacturers extending or reconfiguring rooms, laboratory fit-out contractors, and equipment integrators building enclosed process cells.

WhyWhy unit price is the wrong criterion

An FFU runs continuously for the life of the room, so its energy consumption over ten years dwarfs the purchase price difference between a cheap unit and a good one — often by an order of magnitude across a ceiling of a hundred units. Two other consequences follow the same choice: noise, since a hundred units above people working full shifts is a real occupational issue, and classification stability, since a unit without constant-volume control silently loses airflow as its filter loads.

HowComparing units properly

Compare power consumption at the airflow you actually need, not at the unit’s best point — datasheet figures are frequently quoted at a convenient operating point. Insist on closed-loop constant volume rather than open-loop speed setting, so classification survives filter loading. Check sound power at the operating duty, and multiply it by the number of units in the ceiling. Then confirm the filter is a standard size available from more than one supplier, because you will be buying replacements for as long as the room exists.

Equipment this application needs

Centrifugal Fans FFU fan sections Centrifugal Fans702 EC plug fans — efficiency here multiplies across every unit in the ceiling. Ventilation Fans Room extract & balance Ventilation Fans2,163 Extract maintaining the pressure cascade the FFUs supply into. Chilling Equipment Make-up air conditioning Chilling Equipment88 FFUs recirculate; conditioning and dehumidification happen on the make-up air path. Heat Exchangers Energy recovery Heat Exchangers362 Recovering from the exhaust that high air change rates necessarily generate. Ventilation Fan Parts Filters & spares Ventilation Fan Parts261 Filters are consumables — check the size is standard and multi-sourced before committing.

What to check before you order

EC Motor 204
The single most consequential specification, multiplied by every unit in the ceiling.
Variable Speed 106
Closed-loop constant volume, not open-loop speed setting.
Low Noise 654
A hundred units above people working full shifts is an occupational exposure question.
Energy Saving 1,205
Ten years of continuous running dwarfs any purchase price difference.
Stainless Steel 2,070
Cleanable, non-shedding housing suited to the room classification.

Products for this application

Questions buyers ask

What is the difference between constant-volume and speed-set FFUs?
A speed-set unit runs its fan at a fixed speed; as the filter loads and resistance rises, airflow falls and the room can drift out of classification without anything appearing wrong. A constant-volume unit measures flow or pressure and adjusts fan speed to hold the design airflow across the filter’s whole service life. For a classified room, that difference is the difference between compliant and not.
How much does FFU efficiency actually matter?
A great deal, because the units run continuously for the life of the room and there are usually many of them. Over ten years the energy cost difference between an efficient EC unit and a cheap one, multiplied across a full ceiling, typically exceeds the entire purchase cost of the units — which is why unit price is close to the worst possible selection criterion.
How is FFU noise assessed?
By taking the sound power at the actual operating duty and accounting for the number of units in the ceiling — a single unit’s figure is meaningless on its own. Operators work full shifts underneath them, so the combined level is an occupational exposure question rather than a comfort preference.

Related applications

Cleanroom & Pharmaceutical HVAC Air handling for controlled environments, where the design driver is air change rate and pressure cascade rather than cooling load — and… Semiconductor & Electronics Cleanroom Air The tightest air specification in industry: particle counts orders of magnitude below pharmaceutical cleanrooms, plus temperature, humidity and airborne chemical control. Hospital Operating Theatre Ventilation Ventilation designed around an open wound: clean air delivered over the surgical field, pressure cascades that keep contamination out, and equipment that…

Tell us about your fan filter unit selection project

Send the duty and site conditions and we will come back with matched equipment, price and lead time from the manufacturers listed here — usually within one working day.