TerraBloom ECMF-150, Quiet 6" Inline Duct Fan with Variable Speed Controller – Ventilation Exhaust Fan for Heating Cooling Booster and Grow Tents

This gorgeous piece of equipment comes in a tidy package that's absolutely perfect to connect into a round duct to move air where you want it. Despite its small size it moves a lot of air.The design resembles the compressor on the front of a jet engine: the fan blades are aerofoil-shaped, not just bent pieces of sheet plastic or metal. Yet noise levels are low, almost imperceptible at lowest speeds. And speaking of speeds, you can adjust from very low to very high.All in all, the Terrabloom fan a quality piece of gear that does a terrific job at a modest price. I'm really impressed.

I’ve been using bilge fans to provide simulated wind for a flight simulator but they are sleeve bearing, brushed, DC motors and wear out under sustained high RPM operation. I started looking for an alternative and found these. Early into their use but they are perfect! With electronic commutation there are no brushes to wear out and the ball bearings are rated at 70,000 hours, 8 years, continuous. The kicker is the control circuit. You can use the supplied potentiometer for manual control, but there is a 300mA, 10V supply for the pot that can also be used for signal conditioning from logic level control circuitry. These will take a DAC voltage, a digital potentiometer wiper, or a PWM signal. It just needs to fit in that 0-10V window. The PWM signal is very tolerant of PWM frequency. You just want to make sure the square wave bangs the full 0-10V input range to be able to access the full RPM range of the fan. The only down side I can find is that there is a soft start characteristic where there is a time constant to speed changes. For my application the time constant is a bit long but in practice shouldn’t be too noticeable. The time constant makes for about a 10 second spin up from stopped to full speed. Most won’t care but there is a bit of lag that may be an issue for some applications.Construction is sturdy and these seem very well designed and built. The outer case is steel and nicely formed and painted, but what mattered more for me are the innards. The inlet is sculpted to smooth air flow to the rotor, and the air channel expands back out to full ID to slow the air into the stator area. 7 rotor blades and 7 stator blades. Mold lines are clean and there is minimal flash. They really seem well-built. And maintainable. You will void your warranty but it looks like these can be disassembled if they ever do need lubrication or cleaning. I say looks like because I haven’t actually tried it but phillips screws are used throughout. There is a tamper seal that will tell the tale, though.And they are quiet. Way more quiet than bilge fans. At low speeds you can’t even hear them. At high speed you get some wind noise and some inlet whine (5000 RPM at full speed) but it’s a huge improvement over the bilge fans. When they say quiet, it’s not exaggerating.5 stars hands down. These ECM fans are near perfect for any automated fan control applications. It just takes level shifting of some sort to control these with PCs, Arduinos, or Raspberry Pi SBCs. I2C and SPI DACs and pots that are high voltage tolerant on their outputs should work fine. There is also an open collector tach signal for those who want closed loop control or just to know the fans are turning.PWM control is new to these fans so if that’s important to you, just look for the 4-conductor 1/8” miniplug connectors. The new ones use those. Customer service is great and Steve has been super helpful in getting answers to my inane questions.I don’t have much time with these to comment on longevity but with the alternative control built in, EC motors, and ball bearings on top of surprising engineering in the inlet, rotor, and stator regions, this series of fans are hands down winners.

Product was well-packed and worked out of the box.I used this to build a prototype of a ceiling-mounted area filter. The first version is just a table or floor mounted box with a HEPA filter on the intake. Remote control is essential.The fan was simple to mount, the 6-speed remote control (available separately) works perfectly. The fan is very quiet for the first three speeds and gets louder with each speed setting afterward. It pulls through the HEPA just fine for all speeds.I will be buying at least one more.

As many owners of two story houses with cathedral ceilings I have a problem with air pressure in my master bedroom hvac registers. Put simply - the air pressure is almost non-existing, the length of ducts is extremely long and my brand new furnace has not enough juice to push air from basement 3 stories up. Solution? A booster fan! Thoses with smart guts are expensive. So, I opted for a simple construction fan and separate pressure switch - this thing. It works perfectly. The fan is well made (although in China), relatively quite and powerful enough to push air. Wiring is easy - it comes with power cord and outlet connector, I cut the connector in half and hard wired the end to the pressure switch.The booster fan now turns on when furnace kicks on, and turns off when furnace turns off. Switch is installed into main duct, while the in-line booster fan is about 5’ down the duct, in a branch 6” duct. I was worrying that the pressure that fan creates will be enough to trip the switch but my worries were baseless. Even on maximum speed this 240cfm fan allows the switch to turn off when the furnace is off. I cannot be happier with how everything worked out. Separate speed control is great - I tuned speed to about 50%, which gives me enough air pressure with not much noise.

Using it to extract fumes from a home garage hobby welding shop. Works really well and is very quiet. Quite strong. I accidentally had a glove get sucked up the intake tube I attached to it. Did not damage the unit but showed it has real sucking power.