4 5 6 8 inch RAM Inline Mixed Flow UK Plug Hydroponics Grow Fan upto 840m3/hr (100mm 4"- 199 m3/hr)

Great fan looks nice good price and is very powerful. i was surprised how good this fan is but the only thing is it can be a little loud on full speed but low speed is so powerful I don't need to use top speed.in a 1x1m tent. Recommended!

does exactly what it says on the label!!

great airflow for the price! bit bulky but made of good materials. little bit louder than expected, makes a hoover type noise but way quieter than a actual vacuum cleaner, I've turned the cardboard box it come in into a make shift acoustic box the best i can, with adjustments it can be a manageable noise level for those who want it to go unheard.

Bought this despite reading reviews that it "sounds like a jet engine" etc.. I was wanting a powerful fan.This is anything but. It moves about as much air as an average PC fan, yet sounds a lot louder, although not worthy of the "jet engine" claims. It has a cheap plastic case and a dodgy electrical input that made it cut out for no reason. Probably a fire hazard, worse than useless.I even bought the RAM speed controller to go with it, but this doesn't have the continuous control I was expecting. It just causes a nasty buzzing noise if used, and has two or three different positions where there is different airflow, and at least half of the dial is "off" i.e. the fan is stopped but still making a buzzing noise.Completely naff. Why did I buy this?

Great extractor for the price. Plugged in to test and made very little noise and once secured with screws I can't imagine it would vibrate much at all, seems really smooth.

Excellent budget exhaust fan. Does exactly what I needed it to do. Runs a little loud but as expected from a fan

Writing this after 4 months of 24h/7 use.This is the 100mm 4"- 199 m3/hr fan.Let me first outline the setup:2x hepa filters each 30x30x5cm one after another and an activated carbon 30cm cylinder.All filters are housed in a MDF box in the loft.The fan stands next to the box connected with a short run of 100mm hose.The fan sucks the contaminated air through the box with filters.The fan pumps the air via 8 meters of 100mm hose, including 4 sharp bends, into the house.Air flow test:I am no expert so tested the air flow experimentally by filling a 70 litres plastic bag.It took about 2 or 3 seconds.That's 23 to 35 litres per second and that computes to 82 m3/hr to 126 m3/hr (104 m3/hr average).I think that this is a good result taking into account all the obstructions.Conclusion:A person breathes up to 3 m3/hr, so this single fan could theoretically provide enough filtered air for 27 people.The noise:The fan sounds like a small jet, regardless of speed setting.I wrapped the fan in a duvet and placed it in the loft while the loft hatch is foam insulated.The noise was still annoying in the bedroom 8 meters away.The vibrations:It is incredible how much low frequency vibrations this fan creates.House is made mostly of concrete/brick while the loft joists are timber.With the fan placed on a floorboard in the loft, the rumble in the bedroom was comparable to a truck left engine running outside.I could feel the floor and walls vibrating.Unbelievable! It's got to be a design error. Improper bearings used, perhaps.The ugly solution:Fan placed on a stack of cushions, to include a memory foam cushion.The fan can't touch any solid object as the vibrations will transfer over.Connecting the fan directly to the MDF box caused so much resonance that the box was buzzing!Therefore, it had to be connected to the filters array via a hose.Essentially, the fan is buried under layers of soft fabric and a smoke detector installed right next to it!

This is a very affordable in-line fan, robust, powerful and quiet, i would have given it 6 stars if i could have.