From air purifiers to vacuum cleaners, HEPA filters have become all the rage these days. Short for High-Efficiency Particulate Air, these filters are one of the most common air purification systems, as they claim to improve almost 100 percent of airborne particles. But there are a lot of misconceptions that surround HEPA filtration, including whether or not air purifiers or filters really do meet the HEPA standards, as well as what HEPA filters can and cannot do. With so many misconceptions, and considering the fact that they can be quite pricy, if you’re thinking about purchasing a HEPA filter, before you do, it’s a good idea to learn as much as you can about this type of filtration so that you can determine whether or not it will be a worthwhile investment.
As mentioned, HEPA stands for “High-Efficiency Particulate Air”, and is a standard that is defined by the US Department of Energy. While it might seem odd that a federal agency would establish a standard for air filtration, it makes sense when you know that HEPA was first created for use in facilities that held nuclear materials back in the 1940s. While shielding can be used to hold radiation, if the particles of dust and moisture that contain radiation are irritated, they can potentially spread radioactive contamination throughout the air via air ducts, open windows, open doors, and even cracks.
HEPA filters were first developed as a way to combat this problem and to contain potentially radioactive particles. Since it was first created in the 1940s, HEPA filtration has been utilized in a variety of applications and industries. Within about 20 years after they were first created, HEPA filters started to be used as consumer filters for vacuum cleaners, HVAC units, and stand-alone air purifiers.
Picture a piece of mesh that’s made up of tangled pieces of thin fibers. Usually, the sheet is folded into pleats, which increases both the surface area, as well as the life, of the filter. When air flows through the fibers, particles will get trapped within them. That’s a basic explanation of how HEPA filtration works. It’s important to note that when it comes to HEPA filtration, size matters. In order for the tangled fibers to trap particles, the particles need to be large enough. This is important to note, as it helps to clarify what HEPA filters can and cannot filter out.
So, what does HEPA filtration work for? It’s mostly effective at removing larger pieces of particulate matter; pet dander, pollen, and dust mites, for example. Smaller particulate matter can get trapped within the filter, but can potentially cause the air filter to fail.
There are several types of particulate matter that HEPA filters cannot remove, including many types of harmful contaminants that aren’t particulate matter. Examples include:
It is very important to note that replacing HEPA filters on a regular basis is a must. That’s because all types of pathogens accumulate on and in the filter, including living organisms, and eventually, the pathogens are filtered out into the air.
Before you decide to purchase a HEPA air purifier, you first need to understand that they are only a part of the solution for improving the quality of your home’s air. As you probably gathered from the information presented above – especially in regard to submicron particulates, like VOCs and viruses.
If you’re concerned about larger particulate matter, like dander, pollen, and dust, HEPA filtration may be a good choice for your needs. If, however, you’re looking to eliminate other types of indoor air pollutants, like viruses, bacteria, and VOCs, HEPA would likely be unsuitable for your needs.
As was already discussed HEPA filtration isn’t necessary and usually shouldn’t be considered a full solution for the removal of all types of indoor air pollutants. Fortunately, however, there are additional things that you can do alongside the use of a HEPA filter to effectively improve the indoor air quality of your home. Examples of things that you can do alongside a HEPA filter include:
If you decide that you think HEPA filtration would be an asset for your home, it’s a good idea to know which type of HEPA filter to use. If you believe that HEPA is the right option for your needs, be sure to pay attention to a few variations of HEPA filtration. It’s also important to understand that the US HEPA standard is the one you should opt for.
To make the process of purchasing a HEPA filter more confusing, some air filters are labeled “HEPA-like” or “HEPA-style”. These labels are meaningless, as the terms don’t certify that the filters actually meet the standard. As such, manufacturers whose products meet the standards are starting to use the “True HEPA” term.
HEPA specification is based on the size of the particles and the amount of those particles, as well as the amount that pass through the filters. In order to meet the standards, a HEPA filter must be able to prevent 99.97 percent of all particles that measure 0.3 micrometers in diameter. As such, if you were to send 10,000 0.3 micrometer particles through a HEPA filter, only three particles would be able to pass through.
There isn’t any other aspect of the HEPA standards that is commonly overlooked. This includes the construction of the filter case, and it has to be airtight. If the flow of air can make its way around the filter, the filter will not work as well as it should