Can a Higher Merv Rating Restrict Airflow?

The short answer to the question of whether a higher Merv rating can restrict airflow is yes, but it's not really a problem, except in extreme circumstances. Most modern HVAC systems have no problem working with higher Merv filters, which is why millions of homeowners depend on them. The main risk of high-efficiency air filters comes from the fact that they are not modified for long periods of time. If you keep abreast of changing filters, you are unlikely to experience any filter related issues with your HVAC system.

In general, a filter with a higher MERV rating will reduce airflow. However, there are many other factors at play, such as the size of the filter and the type of fan motor in your HVAC system. Using an air filter with a MERV rating that is too high is as bad as using one that is too low. Air filters with higher MERV ratings can filter more, but the thickness of the filter material can restrict airflow. Restricted airflow can decrease comfort, increase energy use, and accelerate wear and tear on HVAC components.

In particular, using an air cleaner with a MERV rating that is too high can damage the compressor, heat exchanger, and air conditioner coil. In general, filters with higher MERV ratings capture higher percentages of particles, as well as smaller particles. And MERV-13* is practically where you want to be. As you can see above, research shows that in general, HVAC systems with high MERV* filters have a higher pressure drop across the entire filter. This part is common to the three previous studies. A MERV rating is a good indication of the effectiveness of an air filter in your central split HVAC system.

The higher the rating, the better the filter. As the MERV rating increases, fewer and fewer contaminants and dust pass through the filter, making the incoming airflow of better quality. If you want your air to at least clean and handle dust, mold, pollen and bacteria, then a Merv 8 will do the job. Finally, I say that there is no price for peace of mind and that if they feel that a high merv filter would provide that they should do so with the caveat that they should replace dirty filters often enough & that it can be a week or two, depending on the MERV rating, the effective area of the filter and the quantity of particles entering your home. The filter area and pressure drop discussion illustrates how HVAC experts are considering all parameters that can be adjusted, without driving costs to unacceptable levels.

For example, general filtration with an 8 MERV will filter down to approximately 10 microns, whereas a 13 MERV filter will have only approximately 0.3 microns through. This comparison table helps highlight the differences between Merv 8 and MERV 11 filters, making it easier to decide which one works best. As an HVAC professional for more than 40 years, I have seen dozens of systems destroyed by the use of highly restrictive MERV filters. Meanwhile, air filters with a MERV 14 rating or higher are designed for commercial HVAC systems that can handle the coarsest filter material. So what can you do to be able to use a high MERV* filter and not suffer a high pressure drop across the filter and consequent loss of air flow (PSC blower) or increased energy use (ECM blower)? In fact, it's quite simple.

I am wearing a layer of MerVi I am using a layer of Merv 1900 3M Filtrete on my mask (I made the mask as a cover so that I could remove the filter to wash it).A MERV rating is to ensure that incoming ventilated air meets area-specific air quality standards.

Merv 8 air

filters are almost as affordable as less efficient products, making them good value for money. All models passed filtration evaluation for 1 or 20 treatment cycles per test 95— 100% pass rate after 3 and 20 cycles for all models tested. MERV 11 air filters can filter a large percentage of fine particles, but a MERV 8 air filter cannot. The MERV rating system ranges from 1 to 20, with the highest rating (20) being the rating used for filters in places such as hospitals.