AC Infinity Cloudline T4, Quiet Inline Duct Fan System with Temperature and Humidity Controller, 4-Inch
The AC Infinity CLOUDLINE T4 duct fan offers a solution for enhancing air circulation in various environments. With a compact size, this device manages an airflow of 205 CFM while operating quietly, producing only 28 dBA of noise. Inside, a mixed-flow design works synergistically with a PWM-controlled EC motor to deliver optimized, energy-efficient, and barely audible performance. The included smart controller allows for customizable climate monitoring and control, as well as programming for humidity, fan speed, and timer settings, including an alarm system. The package also includes a sensor probe, mounting hardware, and two duct clamps to facilitate easy installation. It is ideally suited for use in hydroponic growing spaces, enhancing heating and cooling transfer, cooling audio-video cabinets, and eliminating unwanted odors.
The AC Infinity CLOUDLINE T4 duct fan offers a solution for enhancing air circulation in various environments. With a compact size, this device manages an airflow of 205 CFM while operating quietly, producing only 28 dBA of noise. Inside, a mixed-flow design works synergistically with a PWM-controlled EC motor to deliver optimized, energy-efficient, and barely audible performance. The included smart controller allows for customizable climate monitoring and control, as well as programming for humidity, fan speed, and timer settings, including an alarm system. The package also includes a sensor probe, mounting hardware, and two duct clamps to facilitate easy installation. It is ideally suited for use in hydroponic growing spaces, enhancing heating and cooling transfer, cooling audio-video cabinets, and eliminating unwanted odors.
The AC Infinity CLOUDLINE T4 duct fan offers a solution for enhancing air circulation in various environments. With a compact size, this device manages an airflow of 205 CFM while operating quietly, producing only 28 dBA of noise. Inside, a mixed-flow design works synergistically with a PWM-controlled EC motor to deliver optimized, energy-efficient, and barely audible performance. The included smart controller allows for customizable climate monitoring and control, as well as programming for humidity, fan speed, and timer settings, including an alarm system. The package also includes a sensor probe, mounting hardware, and two duct clamps to facilitate easy installation. It is ideally suited for use in hydroponic growing spaces, enhancing heating and cooling transfer, cooling audio-video cabinets, and eliminating unwanted odors.
The AC Infinity CLOUDLINE T4 duct fan offers a solution for enhancing air circulation in various environments. With a compact size, this device manages an airflow of 205 CFM while operating quietly, producing only 28 dBA of noise. Inside, a mixed-flow design works synergistically with a PWM-controlled EC motor to deliver optimized, energy-efficient, and barely audible performance. The included smart controller allows for customizable climate monitoring and control, as well as programming for humidity, fan speed, and timer settings, including an alarm system. The package also includes a sensor probe, mounting hardware, and two duct clamps to facilitate easy installation. It is ideally suited for use in hydroponic growing spaces, enhancing heating and cooling transfer, cooling audio-video cabinets, and eliminating unwanted odors.
in 28 offers
The lowest price for AC Infinity Cloudline T4, Quiet Inline Duct Fan System with Temperature and Humidity Controller, 4-Inch right now is $207.00 at The Hydro Bros, compared across 26 retailers.
The all-time low was $170.14 on 4 June 2026 — today's price is 22% above the lowest ever. It has been notably cheaper before — worth setting a price alert.
Prices last updated 8 June 2026.
Last updated at 08/06/2026 05:46:46
AC Infinity Cloudline Pro T4 Fan & 69 Pro Controller Combo (AI-CLT4)
Delivery between 9–19 June $159
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 15–20 June $14.19
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 15–17 June $14.35
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 13–17 June $14.01
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 12–16 June $13.97
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 12–17 June $13.68
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 13–17 June $14.30
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 13–17 June $13.52
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 12–16 June $15.40
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 14–17 June $13.40
originally posted on AC Infinity
I bought a CLOUDLAB 642, 4x2 ADVANCE GROW TENT and CLOUDLINE T4. AC Infinity's quality impressed me so much that I ended up purchasing another CLOUDLAB 733, 3x3 ADVANCE GROW TENT, and the CLOUDLINE T4. The only thing that I would request of AC Infinity is to develop a telescoping clip-on mount for the sensor. I like to position my sensor(s) at the same height as the top of my canopy under the middle of my light. I wish I had two of their new oscillating fans! They are on my wish list. I will be recommending AC Infinity to everyone looking for quality products.
originally posted on AC Infinity
I recently purchased the 4in in-line fan with temp.and humidity sensor along with the 4in ducting. It is by far the best fan system I’ve ever used!! If your looking for performance and innovation with a fantastic price point this is the system for you. Especially for the budget grower. The ability to control/adjust the grow environment and up to 4 devices with a swipe of a finger gives you complete control of your grow anytime. It has given me the piece of mind that my plants are exactly where they need to be no matter what stage of life they are in. I was so impressed with this fan I add the charcoal filter to complete my venting system. I highly recommend this fan system wether a novice or a seasoned grower.
originally posted on AC Infinity
Love this fan. More cost effective than models at Home Depot/Lowes. Very quite. I like the variable speed and the LCD display is very easy to use and looks better than a simple white switch. Cord length for the humidity probe and for the fan controller was sufficient to meet my needs having mounted this fan in a wall outside of a bathroom. Feedback from my wife and neighbors is in general: you went way over the top getting a super nice fan for your bathroom, how much did it cost? Then I show them the receipt and explain that it cost a lot less then the fans available at HD/lowes and is a lot nicer. Pros: Cost, quiet, powerful, variable speed, multiple control program options, easy installation. Cons: It would be really great if there was a motion activated option ... MoreLove this fan. More cost effective than models at Home Depot/Lowes. Very quite. I like the variable speed and the LCD display is very easy to use and looks better than a simple white switch. Cord length for the humidity probe and for the fan controller was sufficient to meet my needs having mounted this fan in a wall outside of a bathroom. Feedback from my wife and neighbors is in general: you went way over the top getting a super nice fan for your bathroom, how much did it cost? Then I show them the receipt and explain that it cost a lot less then the fans available at HD/lowes and is a lot nicer. Pros: Cost, quiet, powerful, variable speed, multiple control program options, easy installation. Cons: It would be really great if there was a motion activated option (probe and programming option in controller).
| Duct Size | 4" |
| Mounting Hole-To-Hole Distance | 3.15 X 2.36 in. (8.0 x 6.0 cm) |
| Cord Length to Controller | 240 in. (20 feet) |
| Hole to Hole Distance | 4.71 x 2.64 in. (12.0 x 6.7 cm) |
| Display Size | 3.5 x 1.4 in. (9 x 3.5 cm) |
AC Infinity Cloudline Pro T4 Fan & 69 Pro Controller Combo (AI-CLT4)
Delivery between 9–19 June $159
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 15–20 June $14.19
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 15–17 June $14.35
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 13–17 June $14.01
AC Infinity CLOUDLINE PRO T4, Quiet 4 Inline Duct Fan with Temperature Humidity VPD
Delivery between 12–16 June $13.97
I bought a CLOUDLAB 642, 4x2 ADVANCE GROW TENT and CLOUDLINE T4. AC Infinity's quality impressed me so much that I ended up purchasing another CLOUDLAB 733, 3x3 ADVANCE GROW TENT, and the CLOUDLINE T4. The only thing that I would request of AC Infinity is to develop a telescoping clip-on mount for the sensor. I like to position my sensor(s) at the same height as the top of my canopy under the middle of my light. I wish I had two of their new oscillating fans! They are on my wish list. I will be recommending AC Infinity to everyone looking for quality products.
I recently purchased the 4in in-line fan with temp.and humidity sensor along with the 4in ducting. It is by far the best fan system I’ve ever used!! If your looking for performance and innovation with a fantastic price point this is the system for you. Especially for the budget grower. The ability to control/adjust the grow environment and up to 4 devices with a swipe of a finger gives you complete control of your grow anytime. It has given me the piece of mind that my plants are exactly where they need to be no matter what stage of life they are in. I was so impressed with this fan I add the charcoal filter to complete my venting system. I highly recommend this fan system wether a novice or a seasoned grower.
Love this fan. More cost effective than models at Home Depot/Lowes. Very quite. I like the variable speed and the LCD display is very easy to use and looks better than a simple white switch. Cord length for the humidity probe and for the fan controller was sufficient to meet my needs having mounted this fan in a wall outside of a bathroom. Feedback from my wife and neighbors is in general: you went way over the top getting a super nice fan for your bathroom, how much did it cost? Then I show them the receipt and explain that it cost a lot less then the fans available at HD/lowes and is a lot nicer. Pros: Cost, quiet, powerful, variable speed, multiple control program options, easy installation. Cons: It would be really great if there was a motion activated option ... MoreLove this fan. More cost effective than models at Home Depot/Lowes. Very quite. I like the variable speed and the LCD display is very easy to use and looks better than a simple white switch. Cord length for the humidity probe and for the fan controller was sufficient to meet my needs having mounted this fan in a wall outside of a bathroom. Feedback from my wife and neighbors is in general: you went way over the top getting a super nice fan for your bathroom, how much did it cost? Then I show them the receipt and explain that it cost a lot less then the fans available at HD/lowes and is a lot nicer. Pros: Cost, quiet, powerful, variable speed, multiple control program options, easy installation. Cons: It would be really great if there was a motion activated option (probe and programming option in controller).
In my low headroom unfinished basement wall mounting the fan was not possible. Neither was suspending it from the ceiling with hangers. I had to mount the metal base onto my basement ceiling using a base of 3/4" plywood to span 2 floor joists. The mounting screws for the base were of poor quality and bent when trying to attach the fan to the ceiling. I had to substitute my own screws. I was also surprised the the clamps that hold the motor in place between the inlet and outlet had very tiny nuts that were not attached to the clamps and could be easily dropped or lost. These nuts are crucial in attaching the motor section. The inlet and outlets are much smaller the diameter of 4" flex duct and required crushing the duct to keep it in place. The inlet and outlets are ... MoreIn my low headroom unfinished basement wall mounting the fan was not possible. Neither was suspending it from the ceiling with hangers. I had to mount the metal base onto my basement ceiling using a base of 3/4" plywood to span 2 floor joists. The mounting screws for the base were of poor quality and bent when trying to attach the fan to the ceiling. I had to substitute my own screws. I was also surprised the the clamps that hold the motor in place between the inlet and outlet had very tiny nuts that were not attached to the clamps and could be easily dropped or lost. These nuts are crucial in attaching the motor section. The inlet and outlets are much smaller the diameter of 4" flex duct and required crushing the duct to keep it in place. The inlet and outlets are very slick and straight. Duct that is clamped on tightly can still slide off. The inlet and outlet need a ridge to clamp behind to prevent the duct from slipping off. These are only suggestions to improve on your product. I like the fan it is extremely quiet and has a strong pull. I am hoping for years of air circulation without any problems.
I was looking for a nice ventilation system for an indoor grow project. I wanted something manufactured with high quality parts and craftsmanship. I stumbled upon the T4 which was an upgrade with an integrated temp controller and humidity monitor. After reading hundreds of reviews of this product and many others, I decided to shell out the extra cash and go with the Cloudline T4. Out of the box, I was impressed with the care of packaging. Everything looked great. Installation was a breeze. I adjusted the proper settings and set it to auto. The next day the monitor was flashing between 0 and 32 and the alarm was beeping. I turned everything off and started over again following the directions. The next day it was reading 155... I started over once again. It stayed ... MoreI was looking for a nice ventilation system for an indoor grow project. I wanted something manufactured with high quality parts and craftsmanship. I stumbled upon the T4 which was an upgrade with an integrated temp controller and humidity monitor. After reading hundreds of reviews of this product and many others, I decided to shell out the extra cash and go with the Cloudline T4. Out of the box, I was impressed with the care of packaging. Everything looked great. Installation was a breeze. I adjusted the proper settings and set it to auto. The next day the monitor was flashing between 0 and 32 and the alarm was beeping. I turned everything off and started over again following the directions. The next day it was reading 155... I started over once again. It stayed steady that day. The next day it was reading 0 and 32 again. Waste of money! Hopefully my plants make it until I can find a new fan.
Well worth the investment. Very quiet, easy to install and makes temp/humidity control easy. Will purchase a 2nd unit in future. Found online set up instructions for the digital controller more helpful than the printed instructions. Shipment arrived promptly within days.
Fan bearing type allows mounting in any direction without reduced lifespan. Connected straight into cupboard ceiling and exhausting directly through filter in an vented enclosure, with no corners or ducting to reduce airflow, allows me to use low speed settings and get effective ventilation, extremely quietly. The controller with auto options and temp/humidity display is awesome. Highly recommended.
This is my first inline fan so I don't have a lot to compare it to, but I purchased it with an AC Infinity tent to cut down on the smell of my indoor crop ;). Heard a lot about the company on the Growcast podcast and used their discount code. Mission accomplished! Smell is almost completely cut down, and the fan runs basically silently on its highest setting. The controller included is a nice addition, automated, readable and straightforward, though I wish I could check it when I'm not at home on my own wifi but it's a small quibble and I would guess that would add to the cost. Very satisfied after a week or two of use!
I installed a zero clearance fireplace - essentially a woodstove in a sheet metal box- which is mounted like a fireplace in a 2 x 4 frame face with Hardie Board. I assumed there would be a lot of heat building up in the enclosure - and I was right. Got up to over 120 degrees. I went on line looking for a way to pull the hot air out of the enclosure and redirect it into my basement and I stumbled on the AC Cloudline. The fan looked great but the integrated controller was the clincher. Unlike most things you buy online, I was not disappointed when the product arrived. Top notch quality. Great workmanship. In all candor, I thought maybe they made a mistake on the price. I cut a hole in the drywall in the back of a closet adjacent to the fireplace enclosure to pull hot ... MoreI installed a zero clearance fireplace - essentially a woodstove in a sheet metal box- which is mounted like a fireplace in a 2 x 4 frame face with Hardie Board. I assumed there would be a lot of heat building up in the enclosure - and I was right. Got up to over 120 degrees. I went on line looking for a way to pull the hot air out of the enclosure and redirect it into my basement and I stumbled on the AC Cloudline. The fan looked great but the integrated controller was the clincher. Unlike most things you buy online, I was not disappointed when the product arrived. Top notch quality. Great workmanship. In all candor, I thought maybe they made a mistake on the price. I cut a hole in the drywall in the back of a closet adjacent to the fireplace enclosure to pull hot air from the top of the enclosure. I mounted the fan in the back of the closet. (I opted not to put it in the enclosure since it will be tiled - just in case it needs any maintenance.) I drilled a 4" hole in the floor of the closet. Voila. Warm air into my cold basement. The ability to set a temp to trigger the fan and ramp up the speed as the temperature increases is fabulous. I stopped by my stove shop to tell them how impressed I am with the product and recommended that they carry it. (A lot of stove manufacturers provide ducting solutions to vent warm air to other locations. I am sure that they are all garbage compared to the AC Cloudline solution.) PS - I NEVER write product reviews! Two suggestions. 1. Sell a standard Decora box to mount the controller in the wall. 2. Offer the controller in white. Super p
The Infinity cloudline T4 seems to be of very good quality. Since it has not yet been installed I can make few remarks concerning it's functional outcome. I probably over- bought to some extent, because the only probe I needed concerns temperature, which also is not that necessary for what I am doing with the product. The only thing I would have liked to have different is that either the probe cord would have been longer, or that there would be an extention available that can be added to make the distance between the controller and the probe farther apart. The fact that it is made to be used in temperatures up to 140 F is also an element that is advantagous to me, since it will be mounted in an accessable joist bay in the ceiling close to the wood stove. The ... MoreThe Infinity cloudline T4 seems to be of very good quality. Since it has not yet been installed I can make few remarks concerning it's functional outcome. I probably over- bought to some extent, because the only probe I needed concerns temperature, which also is not that necessary for what I am doing with the product. The only thing I would have liked to have different is that either the probe cord would have been longer, or that there would be an extention available that can be added to make the distance between the controller and the probe farther apart. The fact that it is made to be used in temperatures up to 140 F is also an element that is advantagous to me, since it will be mounted in an accessable joist bay in the ceiling close to the wood stove. The previous fan that was used was an cheap Nutone bath fan and the motor failed due to too much heat, which is around 90 degrees at the ceiling above the stove. I am simply using this product to move heated air from the wood stove in the east side family room to the west side living room, about 20 feet away. The probe is for adding the convenience of automatically the fan off if we forget to once we have left that room in the evenings, while the wood stove's production of heat dies down. Maybe this fan and controller are an overkill, but I'd rather have too many capabilities than too few, especially when to cost as compared with other options is so small.
| Duct Size | 4" |
| Mounting Hole-To-Hole Distance | 3.15 X 2.36 in. (8.0 x 6.0 cm) |
| Cord Length to Controller | 240 in. (20 feet) |
| Hole to Hole Distance | 4.71 x 2.64 in. (12.0 x 6.7 cm) |
| Display Size | 3.5 x 1.4 in. (9 x 3.5 cm) |
