Why Are HEPA Filters and Carbon Filters Separated?

The separation of the two filters has two benefits:

1. When the two filters are separated, the capacity of carbon filter becomes larger, which can improve the filtration efficiency of formaldehyde and prolong the filter’s lifespan;
2. People who do not need carbon filters (no indoor formaldehyde pollution or any recent house decoration) can choose to buy HEPA filters only, thus reducing the cost.