Depending on the model and filter configuration you will have either 2 or 3 filters in your system.
Stage 1 - Technostat Pre-filter.
On average the pre-filter is designed to last up to 6 months of continuous use. Dust levels in the ambient air will affect how long the pre-filter will last. Like a vacuum cleaner bag it is impossible to predict the exact lifespan because that comes down to how it is used. Pre-filters are white in colour and will turn grey fairly quickly within 1-2 weeks of use. This is nothing to be concerned about and simply means the filter is doing its job. After months of use, a dust layer will build up on the exterior of the pre-filter. We recommend checking the dust build-up on the pre-filter every 3 months of use. When the dust layer is approximately 2 mm thick the filter should be replaced.
Stage 2 - Medical-grade HEPA filter.
The H13 HEPA filter is designed to last 3 to 5 years under normal use. Like with other filters the environment in which it is used will determine the filter life.
The outside of the HEPA filter will change colour and turn grey when it needs changing. Generally, for the first two years of use the filter will remain white and then gradually get darker in the final months of its life. Note: the inside of the HEPA filter will always remain white, so it is important to check the outside of the filter which is visible when the pre-filter is being changed.
Stage 3 - Activated carbon wrap filter. (Excluded in V series systems)
The E7 impregnated carbon wrap around filter is designed for light duty use and will last approx. 6-12 months.
All other models utilise granular activated carbon (GAC) filters with kilograms of carbon with a life of 1-3 years depending on use.
Activated carbon filters work by adsorbing chemicals, gases and odours from the air and the more activated carbon in the filter the better it will purify the air due to a larger surface area, it will also last longer. For example: a 6 kg activated carbon filter will last 3 times as long as a 2 kg filter and remove 3 times the amount of pollutants from the air during its life. Activated carbon filters are like large sponges which have an extraordinarily large surface area.
Carbon filters should be changed when they are saturated, this means the filter has entirely filled up with whatever it has filtered from the air during use. You can tell when a carbon filter needs changing because the air coming out of the air purifier will either be tainted with an odour of what it has adsorbed during use, or the air will simply stop smelling clean or smell stale.
Air which is purified through a carbon filter has a very distinct clean smell which is void of all odours, except for a slight sweet smell from the activated carbon itself, most people describe the carbon as having a “fresh smell”.
