Should Carbon Filters Come Before or After HEPA Filters?

When it comes to air filtration, the HEPA filter is usually the first line of defense. It is designed to reduce the particle grain as it enters the filter chamber. This is followed by the carbon filter, which traps chemicals and odors that could damage the HEPA filter. Any remaining particles are then trapped by the HEPA filter.

To extend the life of the HEPA filter, many air purifiers come with a pre-filter. The Smart Air laboratory in Beijing conducted tests to determine whether it is better to push or extract air when air purifiers have filters in the front or rear. Surprisingly, they found no benefit of placing the air filter on the back (pulling) compared to the front (pushing).Activated carbon air filters have been used since World War I, when they were used in gas masks to remove some of the deadly gases used against troops. However, their production and use only grew dramatically after World War II, leading to the development of modern activated carbon air filters and water filters. When considering whether an activated carbon air filter is a good option for your needs, it's important to look at its advantages and disadvantages. As a first line of defense, they filter out a lot of particles before they reach the HEPA filter.

They are also effective at removing strong odors and harmful gases from your home. However, all carbon cells will have the same exposure to incoming air and will absorb an equal amount of contaminants over the life of the filter. The Smart Air data also showed that washing HEPA filters can actually worsen performance. Vacuuming them is a better option for maintaining their effectiveness.