Diversitech 625-AF8 AB8 Air Booster

This fan is waaay too loud. I am using it to blow air between my room with a woodstove to the rest of the house, it is mounted in the wall 15' off of the floor. When hardwired in to a switch and this thing is on full blast it shakes and rattles all over the place even though it is securely mounted. I ended up purchasing the "Duct Fan Speed Adjuster" for another $30 here on Amazon so I could control this thing. This is a relatively quiet fan up to about 60% of it's speed and then after that it just starts rattling and sounds like crap, I'm sure this would be way worse in the actual application for this product (in a duct). There is no way I would ever use this product without the fan speed adjuster but that's $30, this fan was/is $40 so you're into this at least $70 plus shipping and handling costs. I also thought that 420 CFM would be enough for my application, but I was wrong because I can only turn this fan up to about 1/2-3/4 power before my wife complains and my 2 year old runs off scared.

I bought this to make a thermal downdraft fan for the karate dojo I go to. That is, to suck the hot air of the ceiling and push it down to the floor through flex-duct. It wasn't until after I received it that I read in the instructions that it is only to be mounted horizontally. My application is vertical so we'll have to see how long it lasts since I'm ignoring the Manufacturers recommendations. ;-) The pipe around the fan is of a decent thickness and the fan is mounted solidly within. I did have to add a cord to it but since I wired a thermal switch on it anyway this didn't bother me. The fan pushes air well and is fairly quite. But, since I'm mounting it in a warehouse type environment, the forced air heaters drown out any other fan noise anyway.

I got this fan to transfer heat from our living room where our wood stove is to our back bedroom. I used about 20ft of 8" flex duct and put the fan in the middle of the run. The air flow has been great, you can really feel it transferring the heat.So far we've been running it for about 4 months pretty much non-stop without any problems.The noise level is as expected for a fan. With it being up in the attic we can hear a slight hum when it is on, but you have to be listening for it. Most of the noise is just from the air flow through the register.The only negative I can say is there is no built-in mounting options, so I just used used some metal strapping and screwed it to a rafter.

Installed the fan to boost air flow to an enclosed garage. Installation was straight forward. I added a controller to turn it on and off automatically (available on Amazon). The fan makes a big difference in cooling the garage. The fan is not that loud after it is installed (if you are next to it or in the garage), but the sound it makes does travel back along the ducts and sounds like a jet engine in my living room.Overall, I am satisfied with the fan.Con: The fan was shipped in its original box without any kind of protection, and arrived with a significant dent in the fan housing, taking it out of round. It really needed to be sent inside a properly packed shipping box. Fortunately, flexible round ducting is forgiving.

Purchased this fan to replace one I had bought from Graingers several years ago. Fan arrived in good condition. Electrical junction box is small but manageable. Replacement was easy slip fit to existing ductwork. Fan runs quieter than the one it replaced with approximately the same airflow. The best part is that it cost about one third the price of the old fan.

I have been using this booster fan for quite some time and it works great for boosting warm air through the round flex duct that I have in my house