Sleep mode is built for bedrooms. It drops the fan to its quietest setting, dims or turns off the indicator lights, and keeps the purifier running steadily through the night so the air stays clean with minimal hum and no glow to wake you.
PECOAir's Sleep mode can be activated and scheduled on the Molekule app. For those with PECOAir+, it can be activated by using the touchscreen on top of the unit.
For the quietest result, give the purifier a foot of clearance from the wall and set it on a hard floor rather than carpet.