Inline fan ACM 100/100 T

16 dB(A) — the figure that defines the ACM 100

16 dB(A) at low speed is the ACM 100's noise level from independent testing at 3 metres distance. The threshold of normal human auditory perception is approximately 20 dB(A) — the ACM 100 at low speed operates below the audible threshold under normal conditions. It cannot be heard. There is no other 100mm inline duct fan on the Romanian market that reaches this value.

The practical context: installed in the suspended ceiling of a bedroom or office, the ACM 100 at low speed can run continuously throughout the night without producing any acoustic discomfort. At 22 dB(A) at high speed it remains quieter than most residential bathroom extractors at their nominal speed.

Mixed flow vs. axial — why it matters at 100mm

At the small diameter of 100mm, the difference between mixed flow and axial is even more pronounced than at larger sizes. A standard 100mm axial has static pressure of 8–12 Pa — any additional resistance (duct over 2m, bend, external grille) reduces actual airflow to half the nominal or less.

The ACM 100 reaches 33 Pa static pressure at high speed. At 50 Pa pressure (4–5 metre duct with 1–2 bends) it still delivers 69 l/s (248 m³/h). At 100 Pa it still has 33 l/s (119 m³/h) — a standard axial at the same pressure would be at zero airflow.

When this difference matters:

• Ductwork longer than 4–5 metres
• Installations with 2 or more 90° bends
• Extraction through exterior wall against wind pressure
• Systems with terminal grilles or filters adding resistance

3 speeds — exact data from independent testing

Medium speed available — intermediate data on request.

The two-speed strategy:

Low speed (16 dB) — continuous background ventilation, day and night, inaudible. Maintains air quality constantly without periods of CO₂ or humidity accumulation. Power consumption: just 20W.

High speed (22 dB) — activated manually or via sensor when the space is in active use, after showering, cooking or any activity generating moisture or CO₂.

Typical applications

Bedrooms — continuous night ventilation at 16 dB(A) without disturbing sleep. Improves air quality and reduces CO₂ concentration overnight.

Home offices and consulting rooms — silent continuous operation, productivity improvement by maintaining CO₂ below 800 ppm.

Bathrooms and WCs — with ductwork up to 5–6 metres where standard axial fans cannot overcome duct resistance. The ACM 100T timer version is the ideal choice.

Small plant rooms — continuous ventilation at minimal consumption and noise.

Replacement of undersized axial — direct swap on existing Ø100mm ductwork, no modifications.

Construction features that matter at installation

360° rotating motor chassis — the motor body rotates freely relative to the casing, allowing electrical connections to be oriented in any direction relative to the duct. Essential when suspended ceiling space prevents standard connection.

Detachable spigots — the casing is inserted into the ductwork first, spigots attached after. Installation possible when lateral space is minimal.

Separate footplate — fixing plate mounts independently, fan clips into place. Precise positioning, rapid installation.

Clean without removing ducting — motor and impeller extract from the front without disconnecting air ducts. 5-minute cleaning routine.

S.T.O.P. — Standard Thermal Overload Protection. Automatic shutdown on thermal overload, automatic restart after cooling. No manual intervention.

Class II insulation — no earth wire required. Phase + neutral connection only.

ACM 100 vs ACM 100T — what the timer adds

When to choose the ACM 100T: spaces without an automated control system where the fan should continue ventilating for a few minutes after the occupant has left — bathroom after showering, kitchen after cooking, home office at end of working day. The run-on timer evacuates residual moisture and odours without requiring manual intervention.

Full technical specifications

FAQ 

ACM 100 or ACM 125 — which to choose? The ACM 100 (306 m³/h, 33 Pa) covers spaces up to 25–30 m² at 4 air changes per hour with short ductwork. The ACM 125 has higher static pressure (60 Pa) — the correct choice for longer duct runs or higher resistance installations. If unsure, contact us with your duct length and number of bends and we will confirm the right model.

Is 16 dB(A) measured in real conditions? Yes — at 3 metres distance from the fan in independent testing to EN ISO standards, not a manufacturer claim. It is the lowest noise value in the ACM range at low speed and among the lowest available in any 100mm inline duct fan.

Can it run continuously 24/7? Yes — the S.T.O.P.-protected motor and quality bearings are designed for continuous operation. Power consumption at low speed is just 20W — less than a standby LED lamp.

Is it compatible with flexible Ø100mm ductwork? Yes — compatible with both rigid spiral ductwork and standard flexible aluminium ducting of Ø100mm diameter.

Can it be used with a variable speed controller? Yes for the ACM 100. Not for the ACM 100T (timer version). The Vent-Axia 1.5A electronic controller (available separately, ref. W300310) provides variable speed control with On/Off/sensor slider and adjustable minimum speed setting.

How is the speed selected? The three speeds are selected on installation by positioning the motor within the casing — there is no external speed button or switch. The speed is set once at installation based on the duct length and required airflow, and remains fixed during normal operation.

👉 Vent-Axia ACM 125 — Ø125mm higher pressure version 👉 Vent-Axia ACM 150 — Ø150mm 558 m³/h version 👉 Vent-Axia ACM 200 — Ø200mm 972 m³/h version 👉 Complete inline fan range 👉 Airflow calculator 📞 +40 722 667 239 — free consultancy for model selection