HEPA FILTERS
Are your allergies becoming worse even after getting an air purifier? It may be time to take a closer look at your filter quality. With some minor changes in your home, you can reduce the amount of allergens present, and improve indoor air quality.
All it takes is a good HEPA filter or two. Learn more about HEPA filters, how they work, and what in-home filters you can replace with HEPA-certified variants in our guide below.
What are HEPA Filters?
HEPA filters, or High-Efficiency Particulate Air filters, are specialized air filters designed to capture and trap tiny particles suspended in the air. These filters are highly efficient at removing particles such as dust, pollen, pet dander, mold spores, and other airborne contaminants.
Filters that meet the U.S. Department of Energy standards capture at least 99.97% of particles that are 0.3 micrometers in size. This level of filtration makes HEPA filters effective in improving indoor air quality, especially if you suffer from allergies, asthma, or other respiratory conditions.
How do HEPA Filters Work?
HEPA filters operate on the principle of mechanical filtration, using a dense arrangement of fibers to capture and trap particles from the air. Here is how HEPA filters work:
Fiber Arrangement
HEPA filters consist of a mat of randomly arranged fibers, usually made of fiberglass. These fibers create a pathway for air to pass through.
Interception
Larger particles are captured through a process called interception. As air flows through the filter, these particles come into contact with the fibers and are trapped.
Impaction
Medium-sized particles are captured through impaction. They are unable to follow the air stream around the fibers and collide with the fibers, sticking to them in the process.
Diffusion
Smaller particles, which are constantly in motion due to Brownian motion, are captured through diffusion. Their random movement causes them to collide with the fibers and are eventually trapped.
The combination of the above mechanisms is what makes HEPA filters effective at capturing even particles smaller than 0.3 micrometers.
Types of HEPA filters
HEPA filters come in various types, each designed to meet specific filtration requirements. Here are the most common types.
True HEPA Filters
These filters meet the strict standards set by the U.S. Department of Energy, capturing at least 99.97% of particles down to 0.3 microns. True HEPA filters are commonly used in air purifiers, HVAC systems, and cleanrooms.
H13 HEPA filters
These filters are also very effective, capturing at least 99.95% of particles that are 0.3 microns in size or larger. They are often used in medical settings, such as operating rooms and isolation rooms, where the risk of infection is high.
H14 HEPA filters
These filters are the most efficient type of HEPA filter, capturing at least 99.995% of particles that are 0.3 microns in size or larger. They are typically used in applications where ultra-clean air is required, such as clean rooms used to manufacture semiconductors and pharmaceuticals.
ULPA Filters (Ultra-Low Penetration Air)
ULPA filters are designed to achieve even higher efficiency than True HEPA filters, capturing particles as small as 0.12 microns with an efficiency of 99.999%. They are used in industries requiring extremely clean air, such as semiconductor manufacturing and aerospace.
Washable HEPA filters
These filters can be cleaned and reused multiple times, which can save money in the long run. However, they are not as efficient as disposable HEPA filters and may not be as suitable for applications where ultra-clean air is required.
What are the benefits of using HEPA filters?
HEPA filters offer a multitude of benefits across various industries and applications due to their exceptional filtration capabilities. Here are some of their benefits.
High Filtration Efficiency
The primary advantage of HEPA filters is their exceptional filtration efficiency. They are designed to capture a minimum of 99.97% of particles as small as 0.3 microns. This makes them highly effective in removing allergens, dust, pollen, mold spores, bacteria, and even viruses from the air.
Improved Indoor Air Quality
In residential, commercial, and industrial settings, HEPA filters contribute significantly to improving indoor air quality. By removing airborne particles, allergens, and pollutants, they create a healthier and more comfortable environment for occupants.
Respiratory Health Benefits
HEPA filters are particularly beneficial for individuals with respiratory conditions such as asthma and allergies. By trapping fine particles, they reduce the presence of allergens and irritants in the air, helping to alleviate respiratory symptoms.
Effective Pathogen Control
In medical settings, HEPA filters play a crucial role in preventing the spread of airborne pathogens. They are used in hospitals, clinics, and laboratories to create sterile environments and reduce the risk of infection.
Protection of Sensitive Equipment
In environments like data centers, cleanrooms, and laboratories, HEPA filters protect sensitive electronic equipment and delicate processes from damage caused by dust and particulate contamination.
Extended Equipment Life
By preventing the accumulation of dust and particulates, HEPA filters contribute to the longevity and efficient operation of various equipment, including HVAC systems and electronic devices.
Compliance with Regulatory Standards
Industries with stringent cleanliness and safety standards, such as pharmaceuticals and semiconductor manufacturing, rely on HEPA filters to comply with regulatory requirements and quality assurance protocols.
Green Building Certification
Using HEPA filters contributes to achieving green building certifications by improving indoor air quality, which is a key factor in sustainable and healthy building practices.
Common Applications for HEPA Filters
HEPA filters are widely used in various applications due to their ability to trap microscopic particles. Here is a comprehensive list of common HEPA filter applications.
Air Purifiers
HEPA filters are a key component in residential and commercial air purifiers, removing particles such as dust, pollen, pet dander, and mold spores from the air.
HVAC Systems
Many heating, ventilation, and air conditioning (HVAC) systems incorporate HEPA filters to improve indoor air quality by trapping airborne contaminants.
Medical Settings
In hospitals, clinics, and laboratories, HEPA filters are used in air filtration systems to prevent the spread of bacteria, viruses, and other pathogens.
Cleanrooms
Industries such as semiconductor manufacturing, pharmaceuticals, and biotechnology utilize HEPA filters in cleanrooms to maintain extremely low levels of airborne particles.
Automotive Cabin Air Filters
HEPA filters are increasingly used in cabin air filtration systems in automobiles, providing cleaner air for passengers by trapping pollutants and allergens.
Vacuum Cleaners
High-end vacuum cleaners often incorporate HEPA filters to capture fine particles, preventing them from being released back into the air during vacuuming.
Respirators and Face Masks
Personal protective equipment, such as N95 respirators and masks, use HEPA filters to protect individuals from inhaling airborne particles, including viruses.
Food and Beverage Industry
HEPA filters play a role in maintaining hygiene standards in food processing facilities, preventing airborne contaminants from compromising the quality of food products.
Data Centers
Critical infrastructure like data centers use HEPA filters to maintain a clean environment, preventing dust and particulates from damaging sensitive electronic equipment.
Best Air Purifiers with HEPA Filters.
When purchasing an air purifier for your space, you want to be sure you choose the right one. That is why we reviewed some of the best products to help you make an informed decision.
Honeywell HPA300 Air Purifier
The Honeywell HPA300 is a versatile air purifier that is designed to remove up to 99.97% of airborne particles and allergens. It has a CADR rating of 200 CFM, which makes it suitable for medium-sized rooms.
The purifier also has a True HEPA filter, an activated carbon filter, and an ionizer that removes allergens, odors, and gases from the air.
Features
· True HEPA filter removes 99.97% of airborne particles
· Activated carbon filter removes odors and gases
· Ionizer helps to remove allergens, odors, and gases
· Suitable for medium-sized rooms
· Four cleaning levels and a turbo clean setting
Pros
· High Clean Air Delivery Rate (CADR)
· Suitable for large spaces
· Budget-conscious compared to some other models
Cons
· May produce some noise on higher settings
· Filters need replacement
Blueair Classic 480i Air Purifier
The Blueair Classic 480i is a high-performance air purifier with a combination of mechanical and electrostatic filtration technologies.
Features
· DualProtection filters with both mechanical and electrostatic filtration
· Smart sensor technology for automatic adjustments
· WiFi connectivity for remote control
· Compatible with Blueair Friend app
· True HEPA filter removes 99.97% of airborne particles
Pros
· Excellent particle and gas removal
· Smart features for convenience
· Energy-efficient operation
Cons
· Higher initial cost
· Filters can be relatively expensive
Coway Airmega 250 Smart Air Purifier
The Coway Airmega 250 is a smart air purifier that is designed to remove up to 99.97% of airborne particles. It has a CADR rating of 250 CFM, which makes it suitable for medium-sized rooms.
Features
· Activated carbon filter removes odors and gases
· PCO filter helps to remove allergens and gases
· HEPA filter removes 99.97% of airborne particles
· Smart features for remote control and monitoring
Pros
· High-efficiency dual filtration system
· Real-time air quality monitoring with automatic adjustments
· Long-lasting filter
· Energy efficient
Cons
· Higher initial cost compared to basic models.
Levoit H133 Air Purifier
The Levoit LVH133 is a large-room air purifier with a three-stage filtration system, including a true HEPA filter. It has a CADR rating of 133 CFM, which makes it suitable for small rooms.
Features
· Three-stage filtration (pre-filter, true HEPA, activated carbon)
· Air quality sensor with auto mode
· Sleep mode for quiet operation
· Removes odors and gases
Pros
· Cost-effective for its coverage area
· Highly effective at removing airborne particles
· Removes odors and gases
· Suitable for medium to large rooms
Cons
· Not as powerful as some other models
· Relatively loud
Blueair Blue Pure 221 Air Purifier
The Blueair Blue Pure 221 is a sleek and versatile air purifier designed for efficient particle and gas removal with a focus on simplicity and ease of use.
Features
· Advanced particle and gas filtration
· 360-degree air intake
· Washable fabric pre-filters
· Compact and stylish design
Pros
· Efficient particle and gas filtration
· 360-degree air intake for effective air circulation
· Washable and customizable pre-filters
· Simple and user-friendly operation
Cons
· May not have advanced features like smart connectivity
· Limited coverage area compared to larger models
How to Choose the Right HEPA Filter
Choosing the right HEPA filter requires careful consideration of various factors to ensure it meets your specific needs and the requirements of your environment. Here are the factors you should consider when choosing a HEPA filter.
Filter Efficiency Rating
HEPA filters are rated based on their efficiency in removing particles from the air. The standard ratings include HEPA-13 and HEPA-14, with HEPA-14 being more efficient in capturing smaller particles. Choose a filter with a higher efficiency rating if you have specific air quality concerns.
Filter Size
Ensure that the HEPA filter is the right size for your air purifier or HVAC system. Check the manufacturer’s specifications or user manual to find the correct filter size.
Compatibility
Make sure the HEPA filter is compatible with your air purifier or ventilation system. Not all filters are universal, and using an incompatible filter may compromise performance.
Filter Lifespan
Consider the lifespan of the HEPA filter. Some filters may need to be replaced more frequently than others. Check the manufacturer’s recommendations for filter replacement intervals.
Noise Level
Different HEPA filters and air purifiers have varying noise levels. If you plan to use the filter in a bedroom or other quiet spaces, consider a model with a lower decibel rating for minimal disruption.
Additional Filtration Layers
Some HEPA filters come with additional filtration layers, such as activated carbon or pre-filters. These can help capture odors, gases, and larger particles before they reach the HEPA filter, extending its lifespan.
Brand Reputation
Choose a reputable brand for your HEPA filter. Brands with a history of producing high-quality air filtration products are more likely to provide effective filters. Check the warranty terms and customer service reputation to ensure support in case of issues.
Customer Feedback
Read user reviews and ratings to gain insights into real-world performance and reliability. Look for patterns in feedback related to durability, effectiveness, and ease of use.
Cost
Compare the cost of replacement filters for different models. While it’s important not to compromise on quality, considering the long-term cost of filter replacements can help you make an informed decision.
How to Clean and Maintain HEPA Filters
Maintaining and cleaning HEPA filters can ensure optimal performance and longevity. Below are some invaluable tips on how to clean and maintain HEPA filters.
General Maintenance Tips
· Refer to manufacturer guidelines – Always follow the manufacturer’s guidelines and instructions for maintenance. Different HEPA filters may have specific requirements.
· Check the user manual – Read the user manual thoroughly to understand the recommended maintenance schedule, filter replacement intervals, and cleaning procedures.
Regular Inspection
Inspect regularly -Periodically inspect the HEPA filter for visible dirt, dust, or damage. Regular inspections help identify issues early on.
Check the filter indicator – If your HEPA filter comes with a filter replacement indicator, pay attention to it. Replace the filter as recommended by the indicator.
Vacuuming and Cleaning
· Use a soft brush or vacuum – Some HEPA filters are not washable, but they can be cleaned with a soft brush or a vacuum cleaner with a brush attachment. Gently remove loose particles from the surface.
· Washable pre-filters – If your HEPA system has washable pre-filters, remove them and wash them according to the manufacturer’s instructions. Allow them to dry completely before reinserting.
· Avoid harsh cleaning agents – If cleaning is allowed, use mild, non-abrasive cleaning agents or simply rinse with water. Avoid using harsh chemicals that can damage the filter material.
Filter Replacement
Follow replacement schedule – Adhere to the manufacturer’s recommended filter replacement schedule. Even washable filters have a limited lifespan, and eventually, they need to be replaced.
Purchase genuine replacement filters – When purchasing replacement filters, opt for genuine filters recommended by the manufacturer. Substandard filters may compromise the effectiveness of the air purifier.
Professional Maintenance
Professional servicing – For complex air purification systems, consider professional servicing. Some filters may be embedded within HVAC systems, requiring expertise for proper maintenance.
Bottom Line
HEPA filters are an excellent way to reduce indoor allergens and improve indoor air quality in your home. If you suffer from allergies, asthma, sensitivities, and/or any kind of respiratory problems, a HEPA filter in your HVAC system, air purifier, and vacuum cleaner might be just what you need to start feeling better.
If you’re concerned about the level of air pollution and allergens in your home, the best place to start is with a measurement from an expert. This will tell you if you need to take more drastic actions, above and beyond HEPA filters, to improve your air quality.