Wednesday, December 14, 2011

Q&A: How often do I have to change the activated carbon filter?

AllerAir's deep-bed activated carbon
filters typically last 2-5 years.
An air purifier with activated carbon and HEPA can remove a wide range of indoor air pollutants – but many clients are wondering about the filter changes.

How long does activated carbon last? When is it saturated?

There is no all-encompassing easy answer. Activated carbon is the best and safest filter media to adsorb (meaning to trap by way of chemical reaction on its internal surface area) a large number of gaseous pollutants and chemicals.

AllerAir is proud to offer customers 100% virgin activated carbon, meaning it hasn’t been recycled or restocked (that’s why we also don’t accept air filter returns). So when you get your air purifier, it is performing at full capacity and adsorbing a wide range of odors, chemicals and gases.

How long the carbon will last depends on your indoor air quality and requirements. It is not an exact science.

Typically, an activated carbon filter will last about two years, but in many reasonably “green” or “non-toxic” households, it can last up to 5 years. For optimal performance and ease of mind, most people decide to change it after 2 years.

AllerAir suggests the following:
  • Asses your indoor air quality. An air quality test is good, but make sure it takes not only dust and mold into account, but also chemicals and gases. Make a list of possible sources: Building materials such as drywall, paint, adhesives, glues, particleboard, carpeting, window treatments, cleaning agents, pets, etc.
  • When was the last time you renovated? Renovations will put extra strain on your air purifier, since the chemicals, fumes and particles released in the process may fill up the filter faster than usual
  • Make a note in your calendar or put up a reminder notice. Then reassess the situation after two years.

Many people will realize their carbon filter needs changing because it doesn’t seem to be working as well as before – the nose is a good guide.

More questions? Please submit them to, consult our FAQ section or contact AllerAir directly.