MERV 13 filters typically need to be changed every three to six months. However, the frequency with which you need to change your filter depends on a number of factors, including: The type / brand of filter you're using. The size of your HVAC system.
Changing MERV 13 filters every 30 days to 90 days is ideal, depending on use and other factors. While some larger 4” pleated filters can technically last up to six months between changings, the truth is that it depends on a variety of factors.
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.
In some cases, using an air filter that is too restrictive for your system may cause low air flow problems as well. MERV 13 is the highest MERV value safe for residential furnaces; the higher ratings are used primarily in commercial units.
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.
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.
For instance, MERV 8 filters catch larger particles and are less restrictive, while MERV 11 filters catch smaller particles and are more restrictive. This means MERV 11 filters not only have higher initial resistance but also build up additional resistance faster as they capture more debris.
MERV 13 Air Filters
Filters with higher ratings are intended for healthcare and laboratory environments with excellent air quality and HVAC systems that can handle highly efficient filters. Using a filter above MERV 13 in a home is unnecessary and can restrict airflow and damage the HVAC system.
For most homes, a rating of MERV 8-13 is a good start to keep your air healthy.
The abbreviation stands for Minimum Effective Reporting Value. In other words, it's a measurement showing how small the holes are in the filter. The higher the MERV number, the smaller the holes, and the less that can pass through. Ultimately, this is what makes MERV 14 filters not a good choice for home use.
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.
Furnace filters with a MERV 8 rating or higher can effectively remove pet dander from the air. On average, MERV 8 filters remove 85% of large air particles and 50% of small particles. The higher you go the better the filtration will be, but we don't recommend going higher than MERV 13.
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.
Generally, this is how long a filter lasts based on MERV ratings: MERV 1-4 furnace filters should be replaced once a month. MERV 5-8 filters need to be changed roughly every 3 months. MERV 9-11 filters require replacement every 6 months.
A higher MERV rating isn't always better. While higher-rated filters can trap more particles, they can also put additional strain on your HVAC unit and cause your energy bill to go up. In most situations, a filter somewhere in the middle is more than sufficient.
MERV 13 - 16
The MERV scale stops at 16 so this is the most efficient you can get outside of a HEPA filter. These filters have a lot of stopping power so they will catch the most amount of pollutants and allergens in your HVAC system. These filters are recommended to be changed every year.
These high-quality filters trap particles as small as one micron, including Legionella and humidifier dust. MERV 9 to 12 filters are the best filters that a residential HVAC system will accommodate without serious system modifications.
Air filters with higher efficiency ratings may do a better job clearing the air. Still, they'll also force your HVAC system to work harder, resulting in performance challenges and higher energy bills.
A MERV 11 filter is the most popular choice for residential homes. This type of filter can remove most of harmful contaminants from a home environment, including smoke, dust mites, pet dander, mold, pollen, dust and smog.
A common question among homeowners is, “What is the max MERV for a home?” Generally, a MERV rating up to 13 is typically the upper limit for most homes. Using filters with a MERV rating higher than this can be too restrictive, potentially impeding airflow and straining your HVAC system.
The higher-rated filter also captures up to 50 percent or greater of the smallest particles floating through the air. The primary benefit when comparing a MERV 11 vs. MERV 13 filter is that the latter includes stronger protection against airborne bacteria and viruses that spread through droplets in the air.
One disadvantage of the highest MERV rated filters is that: The pressure drop across high MERV filters is more.
Most standard 1” (MERV 8) pleated air filters are good for 60-90 days. If you use a higher efficiency filter (MERV 11 or greater) you may need to change it more often as they can cause an air restriction due to the larger surface area. Filters 4” wide or larger are typically good for 6 months.
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.
The average size of a mold spore is 2-4 microns. Determining the MERV rating for mold spores involves choosing filters that can actually eliminate particles this small. To effectively filter out mold spores, it is recommended to use filters with a MERV rating of 9 or higher.