BlueAir 650E Air Purifier BlueAir HEPASilent™ technology is a combination of electrostatic and mechanical filter technology that delivers more clean air at a faster rate, with less noise. The new BlueAir 650E in-room air purifier is the only air purifier with its room capacity that uses HEPASilent™ technology. Just click on the remote from up to 20 feet away to change operating speed or set the on/off timer; or set your unit on auto mode and let it regulate itself!