What are the two disadvantages of HEPA filters?

Author: Hollis Larkin  |  Last update: Thursday, June 12, 2025

HEPA filters are limited to particulates. There are harmful gases and fumes that may just pass through a HEPA filter. HEPA filters may cause air to become too dry. Finally, some HEPA filters may produce ozone, which is an unhealthy gas that can irritate the lungs.

What do HEPA filters not remove?

HEPA filters will not remove most viruses, because they are simply too small. HEPA filters will also not remove VOCs, or volatile organic compounds, as they are also too small. Still, HEPA filter technology can be combined with other technologies that will remove these things from your air too.

What is better than a HEPA filter?

ULPA filters trap more and smaller particulate matter than HEPA filters. ULPA filters are 99.999% effective at removing submicron particulate matter of 0.12-micron diameter or larger, while HEPA filters are 99.97% effective for eliminating particulate matter of 0.3-micron diameter or larger.

Why are HEPA filters rarely used in homes?

Part of the reason that HEPA filters are so rarely used in HVAC systems is that they are extremely restrictive in terms of airflow. This means that the system needs to be extremely powerful and use additional fans in order to properly draw air through the HEPA filter and circulate it throughout the room or building.

What is the life expectancy of a HEPA filter?

The average lifespan of HEPA filters can vary significantly depending on their usage, environment, quality, and maintenance, as previously discussed. However, as a general guideline, HEPA filters typically last between 6 months to 3 years before needing replacement.

Air Purifiers: Do They Actually Work?

Should I run my HEPA filter all day?

Many people think that switching it off during the night or when they're not present is a logical energy-saving measure, but it is recommended to keep it running constantly. Once you turn off your air purifier, the air quickly becomes contaminated again with mold, dust, dander, and other pollutants present in the air.

How to tell when a HEPA filter needs to be replaced?

There are many factors involved including: usage time, air pollution, filter positioning and even humidity. The recommended time to replace the HEPA filter is between 3 to 6 months which is a very broad average. In reality, a filter should be changed when its ability to filter a high degree of particles is reduced.

What do doctors say about air purifiers?

Medical professionals suggest prioritizing maintaining a clean home and frequently sanitizing frequently used surfaces. Air purifiers should just be an accessory to your cleaning routine, not a priority.

What are the negatives of HEPA filters?

HEPA filters are limited to particulates. There are harmful gases and fumes that may just pass through a HEPA filter. HEPA filters may cause air to become too dry. Finally, some HEPA filters may produce ozone, which is an unhealthy gas that can irritate the lungs.

Is MERV 16 too high for home?

Filters within a MERV rating of 17-20 are almost never necessary in a residential home. A MERV rating of 13-16 is considered hospital level air quality, so it is unlikely your home needs any more than that.

Which is better MERV or HEPA filter?

The type of filter you need will depend on the specific needs of your facility. If you are looking for a filter that can efficiently capture large particles, then MERV 13 is a good option. If you are looking for a filter that can efficiently capture smaller particles, then HEPA may be a better option.

What is the best HEPA filter number?

All HEPA filters have a rating of a MERV 17 or higher. A HEPA filter with a MERV 17 rating will trap 99.97% of air particles that are 0.3-1.0 micron in size and an even better % of particles below 0.3 microns and above (HEPA filters are rated at their worst performance).

What filter is better than HEPA?

We call this "medical-grade" HEPA filtration. You may be aware that there's a filter that removes even smaller particles, called the ULPA (Ultra-Low Particulate Air) filter. The ULPA standard requires removal of 99.999% of particles down to 0.12 microns.

How do I know if my HEPA filter is dirty?

Signs Your HEPA Filter Needs Replacing
  1. The Filter is Damaged.
  2. Power Consumption Rises.
  3. Allergens are High.
  4. Dust and Dirt Build Up.

Is there water which cannot be filtered?

While hard water cannot be filtered, it can be softened to significantly improve your water quality, protect your plumbing system, reduce your time spent cleaning, and more.

Is there a downside to air purifiers?

What are the downsides of air purifiers? There aren't a lot of downsides to having an air purifier in your home aside from the financial investment. Many ionizers, especially older models, can generate ozone when they are operating, which is known to exacerbate asthma.

What MERV rating is best for allergies?

Because not all HVAC systems can use HEPA filters, air filters with a MERV rating of 13 to 16 are the best option to trap pollen, pet dander, mold spores, and dust mites, and they're highly effective for reducing allergens and improving indoor air quality.

Is it healthy to sleep with air purifier?

Recent research by researchers from the University of Reading and the University of Sussex, commissioned by Dyson, has found that using an air purifier can have a positive impact on sleep outcomes.

Can I just vacuum my air purifier filter?

Wash your HEPA filter with warm water and allow it to dry if your model specifically states that water cleaning is safe. You can also soak your filter in hot water if it is extremely dirty. Clean non-washable, permanent HEPA filters using a vacuum to remove dust and debris.

Does Shark vacuum have a HEPA filter?

Although not all Shark upright vacuums have HEPA filters, we've found that the vast majority do, so if you have an upright model, it's quite likely that it has a HEPA filter. The Shark Rotator Lift-Away DuoClean PowerFins Upright Vacuum is one popular model that features a HEPA filter.

Do you leave HEPA filter on all the time?

It's perfectly safe to keep the device running continuously, and the amount of energy it consumes is very small. And the advantages are significant—by running your air purifier all the time, you'll benefit from the best air quality possible, and the cleaner the air, the better for your health!

How do I test my HEPA filter?

The HEPA filter integrity test is typically performed on supply air or exhaust air HEPA filters using a photometer to scan the filter surface for pinhole leaks that could allow the transmission of contaminant particles that would be unacceptable in a critical application.

Do air purifiers help with mold?

Mold is an obvious health risk in any home, but investing in an air purifier can help limit your exposure. The best among them will ideally offer HEPA-level filtration, with this level of filtration being able to trap up to 99.97% of airborne particles down to 0.3 microns in diameter.

How often do HEPA filters need to be certified?

Unless approved otherwise, HEPA filters are tested at minimum once every 12 months, except those installed in ISO Class 5 facilities, which are tested every 6 months. If testing detects a leak in the HEPA filter, repairs must follow an approved patching procedure based on the IEST RP-CC034.

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