Hi!
I’m considering buying some AirGradient ONEs to measure the air quality in our bedrooms. But I was wondering if it will be loud enough to disturb our sleep? I see that, for instance, there is a small fan in the PM2.5 sensor.
What is your experience of the noise made by the device? Is it loud, or barely audible? Do any of you have one in your bedroom?
You can barely hear the fan even if you put your ear on the device. I think the power transformer in my phone charger is louder than the One in my bedroom. 
Mine has been about two feet from my head as I sleep. Depending on how I turn my head or how it is oriented I either here nothing at all, or a barely perceptible buzz. If it’s more than 4 feet away from my ears, I can’t hear it. If there is anything at all between the monitor and my ears, it is completely imperceptible. It’s very quiet.
Agreed that they are very quiet. I’m really bothered by small consistent sound, but I’ve never heard my AirGradients. The Ikea sensors I do hear quite annoyingly.
The main thing for a bedroom is the light. The display is always on and can be quite bright. I’m not aware of any new update to fully disable the display in the official firmware. In ESPHome I created a blank page to display to keep it dark and the ability to adjust the contrast so when it is displaying you can turn it really low, but I have to have it face the wall even then.
The LED bar that gives status indications can be turned off in the official firmware.
There is also a small LED light coming out of the back all of the time from the board and a regular blue flash when the CO2 sensor does a reading.
Something to be aware of, depending on how sensitive you are to lights.
Awesome! Thank you for sharing your experiences! It was actually comments about the IKEA sensors that got me a bit worried. But now I feel thoroughly reassured that they will work out fine.
@MallocArray Thanks for the info about the lights! I was actually planning to use the ESPHome firmware from your github repo together with Home Assistant. Cool to actually “meet” you here in the forum I will probably make an automation that turns off the LEDs, switches to the blank page and sets brightness to zero during the night.
Just ordered 3 units, and can’t wait to check them out!
To add. We are working on a “Night mode” that you could set a time and then the LED bar and display would turn off so that you are not disturbed in the night.
The very faint blinking of the CO2 sensor unfortunately we cannot control but this one I actually don’t really notice at all.