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.
MERV 11 and MERV 13 filters are specifically designed to trap and remove even the tiniest smoke particles from the air. These filters offer superior filtration capabilities and can help alleviate the negative effects of wildfire smoke on indoor air quality.
Upgrading to a filter rated MERV 13 or higher can be especially important during smoky periods to effectively remove fine particle pollution from smoke in the indoor air. Most furnaces and HVAC systems can accommodate a MERV 13 filter without creating equipment problems, provided that the filter is replaced frequently.
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.
HEPA filters are excellent at capturing particulate matter, including the fine particles found in smoke. Removing these particles can reduce the ``smoky'' smell to some extent because you're physically removing some of the smoke itself from the air.
One of the most effective ways to clean smoke from indoor environments is to attach a MERV 13 furnace filter to a box fan. The Puget Sound Clean Air Agency tested this method with air monitors and found that a box fan filter reduced airborne particulate matter dramatically.
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.
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.
Filters rated MERV 8 are an excellent choice for homes without air quality concerns like allergies or respiratory health complaints. A MERV 11 filter, in contrast, provides enhanced filtration by capturing a greater percentage of smaller particles, including vehicle emissions, bacteria, and mold spores.
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.
MERV 12 Pleated Air Filters Plus Carbon
Constructed with electrostatically charged synthetic materials, these filters also feature an activated carbon layer that helps reduce common household odors from pets, cooking, smoke, and volatile organic compounds (VOCs).
The scale starts at MERV 1, which is the least efficient, and goes all the way up to MERV 20. To make matters slightly more confusing, anything from MERV 17 and above is considered a HEPA (High-Efficiency Particulate Air) filter.
MERV 11 filters are ideal because they are effective at catching small particles, while still allowing enough air to pass through the filter. Using the size categories above, a MERV 11 filter can successfully catch65% of E2 particles (1.0 - 3.0 µm) and 85% of E3 particles (3.0 - 10.0 µm).
To get these particles out of the air, you're going to need a serious filter. Filter efficiencies are measured by MERV (Minimum Efficiency Reporting Value). The best filters have MERV figures of 13 or higher.
For most homes, a rating of MERV 8-13 is a good start to keep your air healthy.
MERV rating 9-12
Filters in this range can trap more than 85% of the particles sized 3.0-10.0 microns. A MERV 9 will trap less than 50% of particles sized 1.0-3.0 microns, MERV 10 will stop up to 64%, MERV 11 will get up to 79%, and MERV 12 is capable of catching up to 89%.
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.
Superior Particle Capture: MERV 11 filters excel at capturing smaller particles, including mold spores, fine dust, and pet allergens.
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.
Many New Jersey homeowners ask us about MERV ratings, especially when it comes to choosing between MERV 8 and MERV 11 air filters. Here's what we tell them: Think of MERV 8 filters as a “good” option, and MERV 11 filters as the “better” option for normal residential use.
The Minimum Efficiency Reporting Value (MERV) rating of the filter strongly impacts the Clean Air Delivery Rate (CADR). It is recommended to use a MERV 13 filter(s) to remove the very small particles in wildfire smoke.
MPR 1200+ is equal to MERV Rating 11. MPR 1500 is equal to MERV Rating 11.
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.