2. Health Concerns / Specific Needs: If you are looking for relief from asthma and allergy symptoms, you must use HEPA air cleaners with a level of filtration good enough to assist with removing the particles from the air that are causing the problem. A purifier that is only ionic will (1) not remove as many particles from the air, and 2) performance will degrade over time (electrostatic rods attract fewer and fewer particles as they become dirty). Blueair air filters, on the other hand, capture 99.97% of the smallest particles from dust, pollen, mold spores, pet dander, bacteria, viruses, etc. For those looking to reduce or remove tobacco smoke, fumes, VOC's (volatile organic compounds-from paint, chemicals, etc), some Blueair air purifiers come with a Gas & Odor SMOKESTOP filter that strongly addresses those needs. In short, get the right filter as well to address your individual concerns.

3. Room Size: How big is the room  where you want to purify the air? Choose a unit that can handle the total volume of air in the room. Remember that high ceilings affect the total cubic footage. Compare the suggested room size (in square feet)  for each unit and choose the unit with coverage closest to the size of the area you wish to purify. For example, if a unit lists a room size of  144 square feet or larger, and your room is 10 feet x 10 feet (10 x 10 = 100 square feet), then this unit should work fine for that space. Also consider that more than one unit may be needed to purify all of one's main living / sleeping / working areas. See our Specials page for amazing deals when you buy 2 or more units!

4. Manufacturer claims:  When comparing HEPA air cleaners, it is important to know that AHAM (Association of Home Appliance Manufacturers) is a good, reliable source of unbiased information. So when air purifiers and cleaners state that they are AHAM Certified, that's usually a good sign. However, just because an airpurifier doesn't have the AHAM seal, it doesn't mean it's junk. AHAM charges fees for their services and some manufacturers, while offering high quality air purifiers and cleaners, simply haven't paid the fees to become certified--i.e. Alen, Aller Air, etc. 

5. Indoor environmental factors      The air where you will be using air purifier and cleaners is an important consideration. Be sure to match the HEPA air cleaners / air purifier filters that best match the conditions in the area where you want to purifiy the air. For example, if your concern is mostly dust / particles, you'll probably do fine with a unit with a quality HEPA air filter that removes 99%+ of the particles in the air. If you have odors, smoke, or chemicals, make sure the unit / air purifier filters contain activated carbon, and the more carbon the better.  For mold, bacteria, virus concerns, make sure the unit has UV light and or negative ions (OH ion, not ozone) that destroy these contaminants.  If you are unsure about what's floating around in your air, but you would like to know for sure, consider an air test kit.   Also, if you have a problem with dampness or the area has recently been flooded, consider a dehumidifier humidifier unit as well. Many people do not realize that excess moisture in the air is a breeding ground for bacteria, viruses, etc and must be used together with a good HEPA air purifer to effectively purify moist air. Conversely, air that is too dry tends to contribute to dust formation and respiratory irritation, so using a good humidifier and setting the indoor humidity level can be important as well.

6. How much does it cost to operate?:  Operating costs consist mainly of two things: energy use and filters. Compare the energy used in watts on all settings suggested filter life or replacement recommendation. Quality air purifier filters and hepa air cleaners are, in general, going to use more energy simply because it is pushing air through the dense filter media and a sealed housing, but it's certainly worth the extra few cents to get much higher performance!

7. Construction:  What is the unit's housing, other parts made of?  Some are galvanized steel, others are plastic. Is the unit UL rated (underwriter's laboratory) for quality construction? Many air purifiers and cleaners are made of solid metal construction; others are pretty much all plastic. If you want something to last for 10-15 years,  get a unit that is made of quality materials.

8. Easy to Operate?:  Be sure to compare not only ease of access to controls, adjustment of settings, etc, but also the maintenance requirements--some air purifier filters require cleaning, washing, etc on a regular basis. Choose air purifiers and cleaners with an operation / maintenance that best suits your idea of 'easy to operate'.

9. Warranty:   Good HEPA air cleaners will have a solid 3-5 year warranty, or longer. Read the details on the warranty, what it covers, for how long, etc.

10. Noise:  Compare the listed noise level between the HEPA air cleaners you are considering, and at the level of operation at which you'll most likely be using it, i.e., high, med, low, etc. For a reference, a normal conversation between two adults is about 50 dBA or 'decibels'.  Many times your air purifiers and cleaners have reviews that will highlight whether a unit is particularly quiet or noisy.