The AC Infinity CLOUDLINE PRO T4 is a 100 mm (4″) smart inline duct fan — 384 m³/h (226 CFM) at 26 dBA, the quietest fan in the CLOUDLINE range, with the full Controller 69 Pro on the end of it. A mixed-flow impeller and PWM-controlled EC motor do the moving; the controller does the thinking: temperature, humidity and VPD triggers, dynamic speed, timers, schedules and WiFi app control. It is the fan for small spaces where you still want the environment managed rather than just ventilated.
Smart climate control
The Controller 69 Pro does more than switch the fan on and off. Set temperature, humidity and VPD triggers and the fan responds proportionally — speed rises as conditions drift and eases back as they recover, instead of slamming between off and full. Set a minimum speed and it never fully stops, so you keep constant air exchange through a carbon filter rather than letting odour build between cycles. Timer, cycle and schedule modes cover lights-on/lights-off routines, intermittent subfloor extraction, or a bathroom run-on after a shower.
Connect over WiFi to the AC Infinity app for remote control, push notifications, historical climate charts and CSV export. Small spaces swing faster than large ones — a 100 mm fan is often working in a volume where a closed door and a warm afternoon move humidity 15 points in an hour, which is exactly the case automation earns its keep. The controller drives up to four UIS™ devices, so one unit can run this fan plus a Cloudray clip fan, a Cloudforge humidifier or an Ionframe light.
Quiet, energy-efficient performance
Most cheap duct fans use an AC motor — loud, one-note, and only crudely controllable. The T4 uses a PWM-controlled EC motor, which is why it can idle at genuinely low noise and why it draws so little power: 21 W average, 28 W maximum. That draw also falls away steeply as you dial the speed back, because fan power scales with roughly the cube of speed. An AC-motor fan pulls close to its full rated wattage the moment it's switched on, whatever speed you've set it to.
The mixed-flow design and 223 Pa static-pressure rating are what hold airflow up once you add a filter, a bend or two and some flexible duct — though 223 Pa is the lowest rating in the CLOUDLINE range, so a 100 mm carbon filter on a long run will take a meaningful share of it. AC Infinity rate the dual ball bearings at 67,000 hours, the fan mounts horizontally or vertically, and the motor box detaches from the frame so you can pull it out and clean the impeller without dismantling your ducting.
What people use it for
Home ventilation
- Bathroom, laundry and ensuite exhaust (ducted)
- Single-bay subfloor and underfloor extraction
- AV cabinets, racks and equipment cupboards
- Small workshops, studios and hobby rooms
- Humidity-triggered room-to-room transfer
Hydroponic ventilation
- Grow tents up to 0.9 × 0.9 m (3×3)
- Propagation and small hobby setups
- Automated VPD-based environment control
- Fresh-air intake on a larger tent
- Quiet setups where noise matters more than volume
Full specifications
| Manufacturer | AC Infinity Inc. |
| Product / model | CLOUDLINE PRO T4 / AI-CLT4 |
| UPC | 854759004785 |
| Duct diameter | 100 mm (4″) |
| Fan dimensions | 188 × 303 × 176 mm |
| Mounting-hole spacing | 80 × 60 mm |
| Screw-hole diameter | 5 mm |
| Cord to controller | 3.05 m |
| Power cord | 2.44 m |
| Controller dimensions | 132 × 74 × 27 mm |
| Controller mounting spacing | 120 × 67 mm |
| Controller screw-hole diameter | 3 mm |
| Display size | 90 × 35 mm |
| Sensor-probe length | 3.66 m |
| Maximum airflow | 384 m³/h (226 CFM) |
| Maximum noise | 26 dBA |
| Static pressure | 223 Pa |
| Voltage / frequency | 100–240 V AC / 50–60 Hz |
| Maximum / average power | 28 W / 21 W |
| Current | 0.4 A |
| Power connection | Australian three-pin plug |
| Operating range | 0–60°C / 35–85% RH |
| Ingress protection | IP44 |
| Mounting | Horizontal or vertical |
| Bearings | Dual ball |
| Rated bearing life | 67,000 hours (manufacturer rating) |
| In the box | Fan unit, Controller 69 Pro, corded thermal probe, two duct clamps, mounting hardware, manual |
| Certifications | SAA · CE · ETL · RoHS · IC |
| Product manual | CLOUDLINE S & T series manual (PDF) |
FAQ
What's the difference between the CLOUDLINE T4 and the S4?
The fan itself is identical — same motor, same impeller, same 226 CFM. The difference is control. The S4 comes with a corded 10-speed dial. The T4 comes with the Controller 69 Pro, which adds temperature, humidity and VPD triggers, dynamic speed, timers, schedules and WiFi app control. If you'll set a speed once and leave it, the S4 saves you money. If you want the fan reacting to conditions on its own, you want the T4.
Is a VPD controller overkill on a 4″ fan?
Sometimes, and it's worth being honest about it. If the fan's job is to clear a cupboard, vent a laundry or keep an AV rack cool, you will set a speed once and never touch the controller again — buy the S4 and keep the difference. The T4 earns its price where conditions actually change: a sealed small tent, a subfloor that only needs extracting when humidity climbs, a room that swings with the afternoon sun.
What size space will a 100 mm fan actually handle?
As a working guide: tents up to 0.9 × 0.9 m (3×3), AV cupboards, a single subfloor bay, a bathroom or laundry on a short duct run. If you are running a 1.2 × 1.2 m (4×4) tent, or a carbon filter on more than a couple of metres of ducting, step up to the T6. A 4″ fan pinned at level 10 to keep up is louder, hotter and shorter-lived than a 6″ fan loafing at level 5, and it will still move less air.
Will it pull properly with a carbon filter attached?
Within limits. The mixed-flow impeller holds pressure far better than a straight axial fan does, but 223 Pa is the lowest static-pressure rating in the CLOUDLINE range and a 100 mm carbon filter is a real restriction. Keep the duct run short and straight and you'll be fine for odour control on a small space. If filtration is the main job and the run is long or bendy, size up rather than pushing this one.
Can the Controller 69 Pro be powered on its own, separately from the fan?
No. The Controller 69 Pro draws its power through the fan, so it can't run as a standalone unit. This matters if you've since upgraded to a Controller AI+ and want to redeploy the 69 Pro elsewhere — the workaround most customers use is to plug a clip fan (a Cloudray, for example) into the spare 69 Pro. That gives the controller a power source and gets you a second independent climate zone plus a backup controller.
Can I use it for subfloor, attic or bathroom ventilation rather than growing?
Yes, and the humidity trigger is the reason people choose it for those jobs — the fan runs when the subfloor is damp and stays off when it isn't, instead of running on a timer and guessing. It's IP44-rated and mounts horizontally or vertically. For bathroom exhaust, read the installation requirements above — it must be part of a properly designed ducted system and any fixed wiring needs a licensed electrician.
Is this a genuine AC Infinity unit with Australian warranty?
Yes. Quick Bloom Lights is the official Australian importer and distributor for AC Infinity. Every unit ships with an Australian three-pin plug, SAA certification, and a two-year warranty handled here in Sydney — no shipping units overseas and no dealing with an offshore seller if something goes wrong.
