HEPA filter reviews can be read online through air filter review sites such as Allergy Buyers Club, general product review sites such as Consumer Search, and on the sites of discount department stores, such as Walmart and Target. Online retailers like Amazon also feature HEPA filter reviews.
The Allergy Buyers Club site (allergybuyersclub.com) contains reviews for a wide range of products that can either cause or alleviate the symptoms of allergies. To read reviews of HEPA filters, users can click on the Air Purifiers section of the main navigation bar, as of March 2015. This loads a page that contains air purifiers broken up into categories based on usage purposes, such as smoke air purifiers, asthma air purifiers and pet air purifiers. Under each type is a list of different models, with information about its functions and features as well as site reviews.
All products, including HEPA filters, listed on Amazon's site feature detailed customer reviews. Each review consists of a quantitative satisfaction ranking and a written account of the customer's experience with the filter. Though Amazon does not require its users to purchase a product in order to write a review, it does demarcate those reviews written by a user who has purchased the product through the site.