MERV 13: These high-efficiency filters are often used in hospitals and commercial buildings. They capture bacteria and smoke particles but may reduce airflow if your system isn't equipped for them. Anything above MERV 13: Used in clean rooms and laboratories, these filters trap even the tiniest particles.
ASHRAE currently recommends using a minimum MERV 13 filter, which is at least 85% efficient at capturing particles in 1 µm to 3 µm size range. A MERV 14 filter is at least 90% efficient at capturing those same particles.
In most cases, a MERV 11 air filter isn't too high for residential use. Generally speaking, anything under a MERV 13 air filter should provide very efficient air purification in a home without impacting airflow.
MERV Rating 8-13
These filters are typically the right choice for use in homes and many businesses.
HVAC professionals say MERV 8 is the highest you should go. Filters are there to protect the equipment not you. The higher the MERV rating the harder the furnace has to work. 1/2x a year change the filter unless you have pets then change 3/4x a year.
However, it's worth noting that filters with higher MERV ratings can restrict airflow. While filters rated 13 or below generally don't strain most HVAC systems, those rated above 10 might require professional installation.
Similar to the previous MERV filters, it is often recommended to replace MERV 8 filters every 90 days. As a side note, make sure to replace you air filter with the right air filter size.
MERV 8 filters capture basic particles like dust, pollen, and pet dander and are adequate for most households. Higher ratings, such as MERV 11 to 13, offer enhanced filtration, capturing smaller particles like mold spores and smoke, which is beneficial for those with 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.
Well, MERV ratings range from 1 to 20, with 1 being the lowest level of filtration, and 20 being the highest. Filters that are MERV 16 through 20 are usually only found in hospitals, cleanrooms, and nuclear power plants. The home air filters you're looking for have a MERV rating anywhere between MERV 5 and 13.
MERV Rating
A rating between 1 and 4 will protect your HVAC system, but will not improve air quality. A rating between 5 and 13 is useful in fighting mold, pet dander, bacteria, and some viruses. Anything rated at a 14 or higher has the highest efficiency.
Sometimes, a MERV 11 filter may be too restrictive, particularly for older or smaller HVAC systems not designed to handle the increased pressure drop. If you notice that airflow has diminished or your HVAC unit is cycling on and off more frequently, these could be signs that your filter is too restrictive.
MERV 8 filters have 90 percent efficiency on particles that are 3 to 10 micrometers in size. MERV 1 to 4 – effective at controlling larger particles such as, sanding dust, spray paint dust, lint and carpet fibers. Applicable in residences and in window air conditioning units.
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).
While most newer systems can accommodate filters with higher MERV ratings, if you have an older system, a filter with a high MERV rating may lower the air pressure too much, which can interfere with the system's function or strain the blower.
Washable air filters have a MERV rating of 1-4. A rating of 1-4 means the filter only captures particles larger than 10 microns. Pollen, dust mites and lint are all 10 or more microns in size, so a washable filter could prevent those types of debris from circulating in your HVAC system.
The MERV 11 air filter is the wrong choice for people who do not own pets and do not have any breathing trouble; this is because it can lead to restricted airflow. Air filters with higher ratings can also have negative effects on HVAC components.
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.
You may not need a MERV 11 filter or higher unless you have specific air quality issues or allergies. For the average household, a MERV 8 air filter can be good enough. You'll want to think about factors like how often you want to change your filters and what type of material do you want filtered out of your air.
High-MERV filters increase the static pressure of your system, and if the ductwork is already marginal, this can cause the airflow to drop to a level where the temperature exceeds the furnace's limit.
1“ Throw Away Filter
1” throw away filters are typically a MERV 2 rating. Most Bard products can use either a 1” throw away or a 2” throw away filter. Upgrading from a 1” filter to a 2” filter will give you a higher filtration value. Remember to reference your manual for what your Bard product is capable of handling.
There are thousands of portable air purifiers that can help, but the best room air filter for dust is a HEPA filter. Unlike home air filters for an HVAC system, highly efficient HEPA air filters work very well in a standalone air purifier. A HEPA air filter traps 99.97% of particles in the air.
MERV 8 filters are sufficient for most homes. These filters are capable of trapping particles that exist in the average home, such as dust, pollen, and hairspray. MERV 8 filters allow good airflow and are not taxing on residential HVAC systems.
A pleated filter is made up of different sizes, and readily captures pathogens as small as 0.3 microns, filtering out even the tiniest of bacteria. They are overall more effective in capturing very tiny particles than non-pleated air filters; 99.97% of airborne particles are trapped with a pleated air filter.
One disadvantage of the highest MERV rated filters is that: The pressure drop across high MERV filters is more.