Because HEPA filters are generally considered expensive items, they may not be a good solution for everyone. People shopping for a filter should investigate the many different brands available and take into account the cost of replacing old filters (on models where it is necessary). HEPA vacuums are more expensive than traditional vacuum cleaners, though they are often cheaper than HEPA air units.

Some good questions to ask when shopping for a HEPA filter are:

• Is this filter considered a True HEPA filter? How efficient is it in relation to a True HEPA filter?
  
  
• What is involved with changing the filter? Does it need to be replaced or just cleaned? How expensive is a filter?
  
  
• What kind of substances is the filter capable of removing from the air? What types of particles is it unable to remove?
  
  
• What size room is the filter capable of cleaning? How quickly can it filter all the air in a room?

Anyone interested in purchasing a filter should also be sure to:

• Listen to the filter while operating to see if it is too noisy
  
  
• Measure the square footage of the room (or space) where the filter will be used
  
  
• Ask about the filter’s ability to remove specific allergens (depending on the buyer’s own allergies)
  
  
• Watch this “Stuff We Love” video on a design-friendly HEPA filter