If you're experiencing a buzzing sound, there's a simple solution. If you're using a standard sensor, you can switch to a 9-volt adapter, which significantly reduces the noise. Are you using a low-temperature sensor? Then you can adjust the fan speed directly through the sensor itself. It's very simple: on the front of the low-temperature sensor, there's a small hole; if you poke it with a needle, the sensor will run more slowly.