GermGuardian AC9400W Air Purifier, with Hepa Filter and Cadr Features: True HEPA air filter reduces up to 99.97% of allergens including dust, pet dander, mold spores, and odor Powerful air purifier filters air 4.8x per hour in large rooms up to 402 sq. feet. CADR RATING: Dust (263) Pollen (275) and Smoke (259) Ultra-quiet with 4 speed settings and a programmable timer Product details have been supplied by the Manufacturer, and are hosted by a third party High CADR Performance Circulates the Room Air 4.8X per hour The higher the CADR the faster the unit cleans the air. CADR RATING: Dust (263) Pollen (275) and Smoke (259). CADR (Clean Air Delivery Rate) rating is verified by AHAM (The Association of Home Appliance Manufacturers). The CADR measures the volume of clean air that is produced by an air purifier per minute, indicating how well pollutants are removed. Energy Star Certified and CARB compliant. Large Room Air Purifying System This powerful air purifying system is perfect for large rooms up to 402 square feet. This unit would be perfect for you master bedroom, living room or basement. The CADR provides a recommended room size based on that CADR performance rating and can be useful to consumers when selecting air purifiers " especially if they are searching for ones in different size rooms within their home. Ultra-quiet with 4 Speed Settings and a Programmable Timer You will be amazed at how quiet such a powerful air purifier can be. Sleep mode is an ultra-quiet speed setting that turns display lights off to help darken the room for sleep. This unit offers 4 speed settings and programmable 12-hour timer. You can also choose auto mode, where the units uses the Smart Air Quality Monitor to detect particulate matter, and automatically adjusts the speed based on your air quality. How cool is that? FAQs How do I determine what air purifier I need based on my room size? Small rooms, often below 100 sq. ft. may only require a tabletop or mini tower-style air purifier to circulate the air. Medium rooms that range between 100 sq. ft. and 170 sq. ft. will typically need a floor model that has a larger filter to effectively process the air in the room. Large rooms, over 170 sq. ft. will require a full size tower or box style unit. Most air purifier cartons and descriptions offer specific information on room size or square footage covered by the air purifier. What is HEPA? HEPA stands for High Efficiency Particulate Air. A HEPA filter must capture 99.97% of all particles that pass through it that are 0.3 microns or greater in size. HEPA is composed of a layer of randomly arranged fibers. HEPA filters are often used in airlines, vacuum cleaners, cars, etc. What is CADR? CADR stands for Clean Air Delivery Rate which indicates the volume of filtered air delivered by an air purifier. CADR ratings show the effectiveness of how efficient the air purifier is at capturing fine particles, such as: tobacco smoke, dust, and plant pollens. What certifications do Germ Guardian Air Purifiers have? -AHAM (Association of Home Appliance Manufacturers) CADR (Clean Air Delivery Rate) program, allowing customers to compare smoke, dust, and pollen ratings for different air purifiers on the market. - ENERGY STAR provides certification to products that meet certain standards of energy efficiency through rigorous testing of consumer products. - ARB Certified means that this air purifier complies with the federal ozone emissions limit. Where should I place my air purifier? You can place your air purifier in a room in your home or office, slightly placed away from the wall and any furniture. Depending on the model, it can be placed on the ground or on a table. We recommend placing it in a room that you are using often, or have the most odor, dust, pollen, or pets. Can I leave my air purifier on at all times?Yes, we recommend running your air purifier 24/7, depending on the season, or your needs. How often do I need to replace my filter? GermGuardian air purifier filters should be replaced every 6"8 months depending on use. You can always vacuum off your carbon filter layer in order to extend the life of your filter. How do I replace the filter? Please refer to your product instruction manual. A downloadable version of the manual for your specific air purifier is available under product specifications, or under the support tab. How do I know I need to replace my filter? You will know your filter needs to be replaced when the filter turns from white to gray or black. What is a carbon filter? Carbon filters are also called charcoal or activated charcoal/carbon filters. It is a form of carbon that is extremely porous making it excellent at absorbing. Carbon filters can absorb a variety of chemicals and vapors simultaneously. What is an ionizer? Ionizers can be combined with filters to emit a small charge to the airstream that causes particles to stick to the fi