Portable air purifiers include models for personal usage around one's neck, inside an automobile and small room air purifiers. The auto and small room air purifiers are very popular and used mostly by business people who travel often.  Renting cars and sleeping in different hotel rooms each night depending upon the air quality in the rented car or hotel room can severely affect one's health.  Thus the main need for portable air purifiers.

Portable air purifiers make a big difference in a small hotel room.  A favorite choice amongst sales people is the Roomaid product.  It weighs just five pounds, making it very easy to pack and carry in a suitcase..

This portable air purifier model is very  quiet even when used in a small hotel room.  Although most hotels today have non smoking rooms, often there are all sorts of odors to remove.  Imagine what is in the air particles that you cannot see or smell.  The Roomaid air purifier is very effective in accomplishing its intended purpose of removing smoke and odors in a small space.

Portable air purifiers usually contain a circulation fan to move the air.

Portable air purifiers can be evaluated by their effectiveness in reducing airborne pollutants in the room or area where they are placed. The Association of Home Appliance Manufacturers (AHAM) has defined the effectiveness of air purifiers as measured by the clean air delivery rate (CADR) of the unit. 

The clean air delivery rate is a measure of a portable air purifier's delivery of contaminant free air, expressed in cubic feet per minute. For example, if an air cleaner has a CADR of 250 for dust particles, it is capable of reducing the dust particle levels in the area to the same concentration level as would be achieved by adding 250 cubic feet of clean air each minute to the room or area. While most portable air purifiers may not achieve their rated CADR under all conditions and environments, the CADR value does allow comparison of different branded portable air purifiers.

The CADR should be used to compare any portable air purifier that you are considering to purchase.  The higher the CADR, the more effect the unit. Many of the portable air purifiers tested by AHAM have moderate to large CADR ratings for small particles of contaminants contained in air. However, for typical room sizes, most portable air purifiers currently on the market do not have a high enough CADR value to effectively remove large contaminant particles from the air such as pollen, dust mite, and cockroach allergens.  AHAM has a portable air purifier certification program and provides a complete listing of all certified cleaners with their CADR values on its Web site at http://www.cadr.org