It’s nice to imagine a home that is practically free from dust mites, mold spores, pet dander and other small airborne particles. With the right MERV rating on your furnace filter, you’d probably notice fewer seasonal allergy symptoms, do less dusting and vacuuming and maybe even suffer from fewer colds and flu. MERV is the key to choosing a filter for your furnace that can remove as many of these airborne particles as possible.
What Is MERV?
Air filters and air purifiers are given what’s called a MERV rating – Minimum Efficiency Reporting Value – a system ranging from 1 to 16 (for residential use). It refers to the size of the holes in the filter that allow air to pass through – the smaller the holes in the air filter, the higher the MERV value. Higher-efficiency contaminant removal helps keep indoor air cleaner, resulting in improved indoor air quality.
What Is the Best MERV Rating for Furnace Filters?
When it comes to air purifiers or filters in your AC and furnace unit, do you always want the highest MERV rating that you can? Not necessarily.
There’s a happy medium in finding a filter that will remove the airborne particles that can cause problems yet allow for proper air flow to your system. What’s right for your needs may differ from what’s right for someone else. All heating systems and homes have different requirements, and you must be careful to find the right rating to deliver the wanted benefits without restricting system airflow.
When the Minimum Efficiency Reporting Value of an air filter is too high for the HVAC system to handle, you won’t receive the intended benefits of using such a powerful filter. When the heating and cooling system isn’t powerful enough to pass air through the strong filter, the filter essentially becomes a blockage, which will force the system to run inefficiently, using more energy in attempts to push air through.
We recently had a customer report that his Carrier Infinity thermostat was regularly showing messages that the HVAC system was working at reduced efficiency. We told him he might want to swap out his filter (one with a higher MERV rating) for one with a slightly lower MERV number. That seems to have done the trick for this individual. But anyone who wants the highest possible particle filtration available can make the decision to check the filter after every thermostat alert and change the air filter more often.
Changing Your HVAC Filter
Filter change frequency isn’t an exact science. MERV ratings can impact how frequently the air filter must be changed, but other factors related to your household have a greater impact, such as HVAC system use and indoor environmental conditions.
Filters with a low MERV rating allow more particles to pass through, so they don’t become dirty as quickly as a filter with a higher MERV rating that traps more contaminants. Check the recommendation made by the filter manufacturer and use it as a guideline, then check your filter monthly to assess for yourself if a replacement is required.
Find the Perfect Filter with Star Heating & Cooling
As always, we’re here to help our customers here in Hamilton and Marion counties in Indiana come to the best decision to suit their individual needs. The MERV rating you choose impacts indoor air quality and home comfort, so check with our HVAC pros if you’re having trouble deciding which filter to use in your home. You can contact us at 317-753-0279 or fill out the form on the right side of this page.