As an expert in the HVAC industry, I have encountered many questions about air filters and their effectiveness. One of the most common questions is whether using a high MERV filter has any downsides. The answer is not as straightforward as you may think. First, let's understand what a MERV rating is. MERV stands for Minimum Efficiency Reporting Value and it measures the effectiveness of an air filter in removing particles from the air.
The higher the MERV rating, the more efficient the filter is at capturing contaminants. However, using a filter with a MERV rating that is too high can also have its drawbacks. One of the main concerns with high MERV filters is that they can restrict airflow due to their thickness. This means that your HVAC system may have to work harder to push air through the filter, which can lead to increased energy consumption and potentially even damage to your system. So, while these filters may be able to remove more particles from the air, they can also put a strain on your HVAC system. But does this mean that high MERV filters should be avoided altogether? Not necessarily.
It all depends on your specific circumstances and needs. If you are looking to remove more particles from the air, there are other options available besides using a high MERV filter. Filters with different materials, such as smaller pores, can also effectively trap contaminants without adding as much resistance to airflow. So, it's important to consider your specific needs before choosing a filter with a high MERV rating. Now, let's address the question of whether high-efficiency air filters are safe for long-term use. The answer is yes, as long as you regularly change your filters.
Most modern HVAC systems are designed to work with higher MERV filters, so as long as you keep up with filter replacements, you should not experience any problems. It's worth noting that MERV ratings are not linear. This means that the difference between a MERV 6 and a MERV 8 filter is almost double in terms of the percentage of particles captured. A MERV 11 filter, for example, only needs to stop 20% of particles between 0.3 and 1.0 microns (which are three to ten times larger than a COVID-19 particle). A MERV 12 filter only needs to stop 35% of particles smaller than 0.3 microns, and a MERV 13 filter only needs to stop half of them. So, what is the best MERV rating for your furnace or air treatment device? The answer depends on your specific needs and circumstances.
If you want to prevent droplets from passing through the filter, a MERV 13 filter is likely sufficient. However, if you are looking to filter out dust, allergens, and toxic gases, a MERV 8 carbon filter may be more suitable. It's important to note that using high MERV filters may require more frequent replacements. The higher the MERV rating, the more particles the filter will capture, which means it will get dirty faster. So, if you do choose to use a high MERV filter, make sure to replace it often enough to maintain its effectiveness. Now, let's address some common concerns about using high MERV filters.
Some people worry that washing these filters with alcohol may create dangerous chemicals. While this is a valid concern, it's important to note that washing any type of filter with alcohol can have this effect. Instead, I recommend using sunlight to disinfect your filters or degassing them with activated carbon. Finally, let's talk about the MERV 16 filter. This is the highest MERV rating available and it can filter up to 95% of particles.
In fact, there are even YouTube videos showing how to make your own N95 mask using a MERV 16 filter. However, it's important to note that low-efficiency filters are usually rated between MERV 1-4, while high-efficiency filters start at MERV 13 and above. Additionally, a MERV 12 filter that is only 1 inch thick may be more restrictive than a MERV 12 filter that is 4 inches thick.
