MERV 13 Filter Pressure Drop: Guidance for Facility Managers
In 2020, the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) recommended switching from MERV 8 filters to MERV 13+ filters in order to help protect against the COVID-19 virus. For facility managers this has provided a variety of challenges, including considerations around increased pressure drop in HVAC systems due to the more restrictive nature of filters with higher MERV ratings.
What is Pressure Drop in HVAC Systems?
Pressure drop describes what happens when air pressure is decreased from one section in an HVAC system to another section downstream. As air moves through an HVAC system and encounters a filter, the filter creates resistance to the airflow as it removes particles and contaminants from the air. This results in lower air pressure on the side of the filter from which the air exits. The lower air pressure will then cause wasted energy because the HVAC system will need to spend more time and power to heat or cool the building to the desired temperature.
Are MERV 13 Filters Susceptible to Excessive Pressure Drop?
Filters with higher MERV ratings are more restrictive because they are capable of filtering more particles than filters with lower MERV ratings. Since MERV 13 filters (https://www.rpfedder.com/filtration/merv-13-filters/) are on the higher end of the rating scale, they can be susceptible to excessive pressure drop. The wasted energy (and associated energy bill costs) required to push air through a higher MERV-rated filter to overcome the increased pressure drop shocks some owners.
However, an important factor is that MERV ratings are not standard and the quality of a filter will vary from one brand to the next, meaning that pressure drop will vary between different filters that are rated the same.
- For instance, the most common cause of pressure drop is a dirty filter and some low-quality MERV 13 filters will clog more frequently, leading to increased pressure drop which requires more frequent filter replacements.
- Additionally, some brands drop their MERV rating almost immediately upon first use (e.g., a so-called MERV-13 becomes a MERV-9 as it’s used – it can’t hold its efficiency).
How to Mitigate Pressure Drop Caused by MERV 13 Filters
The good news is that institutions and other commercial/industrial facilities can take steps to lower their overall operating costs by adjusting their air filter strategy, namely by using higher quality or premium filters to save money in the long run.
A lot of people who buy air filters focus on the filter cost, alone. They don’t realize the energy cost difference between cheap filters and premium filters could be 3X to 7X the filter cost! Energy savings of $50 – $100 per filter are not uncommon, which translates to tens of thousands of dollars per year for even a modest-sized building.
Need Help Upgrading to MERV 13 or Higher?
If your facility needs to upgrade to MERV 13+, R.P. Fedder can help you. We offer a variety of premium air filters that can help you meet the latest filtration recommendations while keeping energy costs as low as possible. Rensa Filtration – manufactured by our parent company – makes some of the best filters on the market: they are the most energy-efficient, have a longer and more effective service life than other filters, and feature a lower pressure drop than competing brands.
Our filtration specialists can help you determine the right air filter strategy for your facility.