I bought a house with a sealed crawl space, and radon test showed level in the 4-6 range inside the house. Radon mitigation companies quoted me a minimum of $2500, and they are next to impossible to get an actual response or schedule anything with anyway. So I decided to take matters into my own hands. I researched online that in a sealed crawl space, the EPA actually recommends leaving at least one foundation vent open to allow soil gases to escape. I installed this fan in one of my crawlspace vents and set it to run at 50 power. Within 24 hrs, radon levels were below 2. Within 48 hrs, radon levels were below 0.6. Running at 50 power, this fan is quieter than a whisper. I really like the ability to adjust the fan speed. Two things I don't like: 1) Speed adjustment control is a little digital device that plugs into the power supply via USB-C cable. It would be better if the speed control was a mechanical knob directly on the device; and 2) the power supply cable comes out of the bottom of the fan, which interferes with installation. it would be better if it came out of the back.
Rating:
[4 of 5 Stars!]