VIVOSUN Register Booster Fan with Thermostat Control, Fits 4” x 10” Register Holes, 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!

I was very skeptical when I ordered this, but figured what the heck might as well give it a try! We have a huge master bedroom with no air intake to suck out any of the hot air that accumulates. Our house was never intended for air-conditioning and despite putting one in a few years ago, we still had to rely on a portable air conditioner in our bedroom throughout the summer months. I have to say plugging this one device into a single vent on our floor has actually managed to keep our bedroom cooler than it ever has been. The controls are a little wonky, which is why I gave it four stars but overall, I’m probably going to buy another one for our daughter’s bedroom.

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.

Excellent product makes a difference by pulling in more air from the register. Has variable speeds so you can determine how much heat or cold you want to draw in.