Are Merv 13 filters bad for HVAC systems? The short answer is no, but there are certain circumstances where they can cause problems. Most modern HVAC systems have no issue working with higher MERV filters, so millions of homeowners rely on them. However, if the filter is not changed regularly, it can lead to more expensive problems in the condenser coil. The MERV scale is used to measure the effectiveness of air filters.
A filter with a higher MERV rating captures a higher percentage of particles, as well as smaller particles. MERV-13 is considered hospital-level air quality, so it's unlikely that your home needs more than that. According to the United States Environmental Protection Agency, filters in the range 7 to 13 often have little difference from higher MERV indices, but they will allow the system to operate much more efficiently. When a high-efficiency air filter is left unchanged for long periods of time, it can reduce air flow through the condenser coil.
This can cause the coil to freeze and turn into an ice ball, restricting air flow completely. This can lead to more expensive problems in the outer condenser coil. Most modern HVAC units should be capable of at least one MERV 8 filter. New guidelines from ASHRAE, CDC and OSHA recommend upgrading building ventilation filtration to MERV 13 to improve indoor air quality (IAQ) and reduce exposure to SARS-CoV-2, the virus that causes COVID-19. When selecting a filter for your HVAC system, it's best to choose one with the highest possible MERV rating for your specific system.
It's also important to replace your filter regularly to keep your oven in top condition for years to come. In conclusion, Merv 13 filters are not bad for HVAC systems as long as they are changed regularly. They provide hospital-level air quality and help reduce exposure to SARS-CoV-2.However, if left unchanged for long periods of time, they can reduce air flow through the condenser coil and cause more expensive problems.