Tjernlund RB10W High-Power Register Booster Fan for HVAC - Improves Airflow in Home & Office Vents | Perfect for Bedrooms, Basements & Ductwork Systems

This register booster fan did wonders to regulate the temperature in our nursery, which suffers from low airflow through the vents. There are numerous other models that are built from two computer fans set side by side, but they are all essentially clones of each other with minor differences and are far too weak and noisy to be useful — I tried four different models. The Tjernlund is an industrial grade unit capable of running 24 hours a day and is, at least by comparison, nearly silent using a completely different type of cylinder fan, perfectly fine for our two year old to sleep within a few feet of it.The only catch is it has to fit the vent’s depth. In our son’s room, the duct carrying the air to the vent comes up from below without a 90° bend right before it so there is nothing to obstruct the fan sliding all the way in. The duct leading to the vent in another room with the same airflow problem makes a 90° bend at the point where it meets the vent, and that prevents fitting all the way inside. Bummer.The fan itself has no speed control and the on/off switch is hard to reach, under the vent grate. You can buy this add-on switch (https://a.co/d/ioPbUMv) to adjust it manually. We did that but ultimately returned it because there was never a time we wanted to run it at less than full speed and it’s shockingly expensive.We came up with a much better solution by using a smart plug to turn it on and off with our Alexa — you can use your phone or any other smart controller too. Then we achieved full beast mode when we figured out that the latest Echo Dot has a temperature sensor built in. I was able to set up a routine that turns the vent’s smart plug on whenever it senses the temperature in the room goes above 72° and off again when it drops below 71°. It’s been a set-and-forget system for over a year now. We set up an equivalent routine during the heating season to turn it on when it gets too cold. It would be even better if I could figure out how to connect the smart plug to a smart thermostat and have the thermostat turn it on whenever the AC is running, but this works great for now.FYI there are also duct booster fans (I haven’t done any research but this is a random example from the same company https://a.co/d/fMIIBIv) that get installed directly inside the ductwork—probably an hour or two of work for an HVAC professional if the duct is easily accessible at some point along its path, like in the basement or attic—that work exactly the same way but are much more powerful and effective, and can boost airflow to multiple vents and rooms depending on how high up in the duct branch network you install it.As long as it fits your vent, you’ll be incredibly happy with this Tjernlund model. Outstanding.