VIVOSUN Quiet Register Booster Fan 4”×10”, Smart Register Vent with Intelligent Thermostat Control, Cooling Heating AC Vent Booster Fan, Matte White

Very good product! We use it to pull air from our wood heater in the basement, we have tried a couple of other brands, but they do not rate like this one. Simple to use, very well built, and it moves a lot of air. We do not use it in a vent, but i can see how un-obstructive it would be to the air coming from the HVAC Large opening for the air to pass through, and runs very quietly compared to the others we have. We will be replacing the other brands with this one. :)

Bought this for the vents in a couple rooms in my house, that have poor vent performance. Didn't realize that the inside dimensions of my vents are all 3" by 10", though, so they didn't fit (the inner dimension of your vent does indeed need to be 4x10 to work with these). Plugged it in to test out the performance any way, and: - VERY quiet - Fan seems pretty strong Hard to say exactly how it would have performed if it fit into my vent (and they don't make a 3x10 version that I could find) but worth giving a try if you do have 4x10 vents!

This actually works. When the furnace is on it increases the flow of air into the room and when furnace is not on it continues to pull the warm air into the room to the preset parameters. I’m not waking up at night to turn on my heating pad or electric fireplace. It did take several tries to change from Fahrenheit to Celsius. You have to press the up/down buttons at exact same time and it will eventually switch over. Very pleased with this purchase.

These fans are so loud at max fan speed. I read a max of around 53 decibels. That is the sound of a hairdryer constantly running in the background. I can't slow down the fans, Otherwise the airflow within my workspace would suffer. so I replaced the fans with quieter ones. it turns out that these fans are not special. they are DC controlled 80mm computer fans. So by splicing in noctua fans into the original leads, the fans are now so quiet that you cannot hear them at maximum speed. Obviously the airflow has been cut in half and I cannot displace the same amount of air in an hour as with the old fans. But these are advertised to be QUIET. A hairdryer blowing air 2 feet away is not quiet. Its clearly not and the seller should not advertise that its QUIET. Other than that, it was easy to install. looks okay., and functions as it should. Boosting airflow in rooms that do not have much. Overall, if you are expecting more like a whisper (31 decibels) for these fans, don't bother. the lowest is around the volume of a coversation with no shouting (41 decibles ), to a hair dryer (53 decibels). You need to replace those fans. Thankfully, the process is simple with a soldering iron and a few hours. but for those who want a quiet, all in one solution, go with a different seller.

I bought this to try and compensate the downstairs office temperature which was always a couple of degrees lower than upstairs. My thinking was that it will blow more hot air in the office and will even things out. I have a home assistant and an ecobee so I was able to track the temperature very precisely over time. The verdict after running it for 10 days and looking at the data is: 1. It restricts the airflow significantly when off 2. To get the airflow back to the same level as an open vent you have to run the fan at around 5-6 out of 10. 3. In order to get positive airflow you need to be running it at max speed when it's really loud 4. When it's running it also cools the air which kinda defeats the purpose of improving heating. My data shows that after installing it and running at 5-6 speed for 10 days the temperature at the office never went to the same levels as it was with just an open vent. It might have worked if I ran it at max speed but it is way too loud. I can see how it may be useful for cooling which is why I am keeping it in case I need it in the summer.