Quiet Register Booster Fan Fits 4" x 12" Register Holes, 10-Speed Smart Heating Cooling AC Vent Fan with Remote Control and Thermostat Control - Black

I was a bit skeptical of this item at first, had a different product years ago that didn't seem to help. But the second story in our home tends to run 3-5 degrees warmer in the summer than the main floor where the thermostat is located and took the chance that this may help.Installation was quite easy, just make sure you get the right size, loved that they had a variety of size choices unlike many other competitors.I admit, it took me a few minutes to understand how to lock in the settings correctly, but got them eventually. The highest fan speed is a bit noisy, but we are a fan family and it's more just like background white noise. And we'll take the noise because the velocity with which it pulls the air is quite strong, you can feel it from several feet away!We are very happy with the unit, when the AC is running, it cools the room to the exact same temperature as the thermostat is set, even a degree lower sometimes! That being said, you have to understand how it works. You program the cooling temperature lower than the thermostat setting by a few degrees, but not colder than the temperature of the air when the AC is blowing. The fan should be off until the AC starts blowing, and once it senses colder air, the fan turns on. This means that when the AC is actively blowing, it makes a significant difference in the room temperature. However, if there are longer periods when the AC is not blowing, the room temperature will creep back up because the unit is off (as it should be since it would then be pulling in hotter air just sitting in the vents). Just a word of caution so you have realistic expectations. My only minor complaint is that it does seem to take a couple minutes to turn on after the AC starts blowing, and stays on for a couple minutes after the AC clicks off. But it's a minor issue and does not seem to detract from overall performance.

Best booster fan in the market. Nice product and excellent customer support. I had no issue with the unit. They had promotional discounts for the 2nd & succeeding purchases. I emailed the customer support and responded to me within a few minutes, and they gladly provided me with my discount codes.The unit is very quiet and works well as it was described. Easy to set up. Works well in our rooms with a low airflow. I bought 4 units. This booster fan and the seller are highly recommended, 5 stars all the way.

I have an upstairs that runs too warm all summer. It's big room with one vent fed by at least a 15 foot run of 12" duct. I had been planning to sever the duct and install an inline duct fan up in the attic and either use an expensive pressure switch or tap into the thermostat wire with a relay, but this vent register booster is a much easier to install and less expensive solution - and it's working pretty well!Plugging it in is the only tricky part, but I was able to plug it in up in the attic so no cord is visible. I took my old vent register off and I probed around the edges with one of those wiring fishing rods until I found a gap where the rod could push up into the attic. Then I climbed up in the attic, plugged it into an outlet up there and then taped the end of the cord to the rod so I could pull it back down into the room. The AC register booster has a short 6 inch lead attached to it, and the rest of the wire connects to that. It's obviously heavier than a plain vent register, so it was bit difficult to install because I had to use both hands to hold the register up there and connect the wire and then reach for the screw and screwdriver to fasten it in place without letting go of anything.The thermostat measures the air in the duct so that you can set it a temperature below the normal room temperature, but above the temperature you're reading in the vent when the AC is on and it will turn the fans on only once the cold air starts coming through. Mine started off reading 68ºF in the duct, but after a while I checked it again and the reading was 66º, so I figure it's pulling the cool air through the duct faster and not allowing it to heat up in that long duct in the attic. I still need to replace my AC system, but I can tell that this room is noticeably more comfortable after installing this inexpensive solution first.

Product came damaged but functions. Build quality is not great. As for the functionality the unit works good. There is a noticeable difference in room temp. We bypassed the temp range and went right for the direct fan speeds. Level 10 moved a lot of air, but is a bit noisy. Not horrible, probably half the noise of a box fan. Anything less that level 5 seems like a waste. The temp range works and I look forward to using it this winter to help with temperature differences in each room.

No more expensive portable room air conditioners that last less than 5 years!! These work to cool living areas: kitchen in the mornings, bedroom at night. Can't say they are 'quiet' when fan is set to high (8-10), but it's not invasive, more like airplane engine noise at cruise altitude (white noise actually puts most people to sleep, the reason so many people take a flying nap). Settings are simple to make and so far, no problem with digital panel working as expected.Important Note: these plug into electrical outlet, so carefully consider whether they can plug in near your target register vents. Elec cord is reasonably long.I've only used these for one month (summer) with central ac cooling, so can't speak to longevity, but with my bdrm door closed for an hour before bedtime, they bring temperature down abt 10 degrees (with ac running, then I turn central hvac off at bedtime, bdrm stays cool all night). Colder rooms help with getting to sleep.One more thing. These vent units measure the air temp blowing from the vent, not the room temperature. You select the vent temp -- for summer mine is set to come on when vented air is below 70; next winter over 80. Note: an issue arises when trying to set both at same time (not a flaw, issue is covered in instructions), simple to set it once per season.