Holmes 2133755 True HEPA 360° air purifier 155 sq ft

Room coverage and filter class

The Holmes 2133755 is a true HEPA air purifier rated for rooms up to 155 square feet. Its 360-degree intake pulls air from every direction through a three-stage filter that captures particles down to .3 microns. The system removes up to 99.97 percent of airborne allergens such as pollen, pet dander, and dust mites. A carbon layer also reduces common household odors from cooking and pets.

Upgrade from basic filtration

This unit replaces single-stage or non-HEPA filters that only trap larger dust and hair. The jump is worth it when you need verified removal of fine allergens and smoke particles rather than just visible debris. The 100 CADR rating confirms measurable clean-air delivery for medium bedrooms. Buyers who need whole-home coverage or higher CADR for large open spaces will need a different class of device.

Sustained overnight operation

On its low setting the purifier runs at 30 dB, quiet enough to run continuously through the night without disturbing sleep. The 360-degree airflow path maintains consistent circulation across the 155 square foot area during extended use. Three speed settings let you balance noise and purification rate for daytime or night-time needs. A built-in night light adds a subtle glow without extra hardware.