How the Cloudline Lineup Is Organized
The
AC Infinity Cloudline series splits across three tiers. The Lite A-series uses a basic AC motor with manual on-fan speed dial, ideal for a single tent on a fixed schedule. The S-series adds an EC motor for quieter operation and lower power draw. The T-series adds the same EC motor plus UIS-compatible integration with a
Smart Controller, so the fan speed responds in real time to temperature, humidity, and VPD set points instead of running at one fixed dial setting.
Cloudline Sizing and CFM Reference
| Duct Size |
Tent Footprint |
Lite A / S Max CFM |
T Max CFM |
| 4 inch |
2x2 to 2x4 |
205 CFM (S4) |
205 CFM (T4) |
| 6 inch |
3x3 to 4x4 |
402 CFM (S6) |
402 CFM (T6) |
| 8 inch |
5x5 to 4x8 |
807 CFM (S8) |
807 CFM (T8) |
| 10 inch |
8x8 |
1062 CFM (S10) |
1062 CFM (T10) |
| 12 inch |
10x10 |
1180 CFM (S12) |
1180 CFM (T12) |
Sizing rule of thumb: total tent volume divided by 1 minute of air exchange, plus 25 percent overhead for the carbon filter restriction. A 4x4x6.5 tent is 104 cubic feet, so a Cloudline S6 or T6 at 402 CFM gives roughly 3-4x the required throughput, which is the right margin for a fan running at 40-60 percent most of the time. Running EC fans at lower duty cycles is where the noise and energy advantage shows up.
Which Series to Pick
I default the T-series whenever the build already includes a Smart Controller, since the closed-loop temperature and humidity response is the whole reason to buy the AC Infinity ecosystem in the first place. The S-series is the right call when you want EC-motor efficiency without controller integration, common in a single-tent build paired with a separate temperature switch. The Lite A-series fits a budget setup where the schedule is set-and-forget and the user is not chasing precise VPD control.
Pair every Cloudline fan with a matching
AC Infinity carbon filter at the same duct diameter. For a complete walkthrough of the build, see the
AC Infinity air filtration kits in-depth guide, which steps through filter sizing, ducting layout, and noise control.
Related Guides
For cross-brand comparisons, the broader
inline fans page lines up Cloudline against Hyper Fan, Vivosun AeroWave, and other EC-motor competitors.
Frequently Asked Questions
Which Cloudline for a 4x4 tent?
A Cloudline S6 or T6 (6-inch duct, 402 CFM) is the sweet spot for a 4x4. The 6-inch size has the most accessory and ducting compatibility, and running it at 40-50 percent gives the right air exchange with margin for carbon filter restriction. Step up to the T-series if a Smart Controller is in the build, otherwise the S-series works.
Cloudline S vs T, what's the difference?
Both use the same EC motor and fan housing, so airflow and noise are identical. The S-series has a manual on-fan speed dial. The T-series adds a UIS port that connects to a Smart Controller, which lets the fan respond automatically to temperature, humidity, and VPD set points instead of running at one fixed speed.
Is the Lite A-series quieter than the S?
No, the S-series is quieter at low speed because the EC motor draws less power than the Lite A's AC induction motor. At full speed both are similar. The Lite A wins on price; the S wins on running cost and noise floor at the duty cycles most growers actually use.
Does the T-series need a Smart Controller?
No, the T-series ships with its own basic controller that handles temperature and humidity scheduling for a single fan. The benefit of upgrading to a 69 Pro Plus or Controller AI+ is that one controller then runs your fan, lights, humidifier, and dehumidifier on the same closed loop instead of each device on its own schedule.
Can I daisy-chain two Cloudline fans on one controller?
Yes, the Smart Controller 69 Pro has 8 UIS ports and the 69 Pro Plus has 8 ports plus Wi-Fi. Each T-series fan plugs into its own port, and the controller can run them on the same schedule or independent schedules. Common pattern: intake on one port, exhaust on another, both responding to the same temperature sensor.
What CFM does a 6-inch Cloudline produce?
The S6 and T6 both spec 402 CFM at full speed in free air. With a carbon filter inline, real-world CFM drops 25-35 percent depending on filter age and duct run, so plan around 260-300 CFM through the ducted path. That's still more than enough for any 3x3 or 4x4 tent at moderate fan speeds.
How loud is the Cloudline T6 at full speed?
About 45 dB at the fan housing at full speed, dropping to roughly 32 dB at the lowest speed setting. Most grows run the fan at 40-60 percent, which puts the noise at around 35-38 dB, quieter than a typical refrigerator. Add a duct silencer if the tent shares space with a bedroom or office.
