How to Select Furnace and Cooling Filters
Air filters are very important to the health of your home heating or cooling system. By keeping particles out of your furnace or from clogging A/C condenser coils, they can maintain optimal performance. However, if a filter works too well, it can actually do the same thing as a dirty air filter—choke air flow to your heating or cooling system. The HVAC professionals at R & R Heating & Air can help you select and change your HVAC system filters to maintain optimal efficiency and indoor comfort.
The MERV Scale
Furnace and A/C filters are rated along the Minimum Efficiency Reporting Value (MERV), a scale that ranges from 1 to 16. The higher the number, the finer the filter and the finer the particles it can trap.
On average, most residences employ a filter between four and twelve on the MERV scale. However, the furnace industry widely utilizes traditional spun fiberglass filters with a MERV rating of 2.
What an Air Filter Does
The purpose of a furnace or A/C filter is to remove particles from air that is pulled into your home heating or cooling system. Air needs to be clean for an efficient burn (furnace) or to prevent buildup around condenser coils that can cause freezing. A clogged filter can kill your blower motor, wreck the heat exchanger and cost you hundreds of dollars in high energy expenses.
That’s why you need a clean air filter. However, before switching from a traditional fiberglass filter to a high-efficiency filter, talk to your HVAC technician. Some high-efficiency filters slow air flow in the same way a dirty filter does, resulting in the same types of damage. However, an experienced HVAC technician may be able to adjust the fan’s speed to account for the decreased airflow, making a high-efficiency filter a better option.
HVAC Filters and Air Quality
Many people are told that furnace and/or cooling filters affect the air quality in their homes, leading them to select filters with higher MERV ratings, but this isn’t actually the case.
Air filters that filter air going into your furnace or cooling system do not remove particles picked up in your home’s ductwork, where the majority of irritants build up. So, regular duct cleaning more effectively improves your indoor air quality than a furnace or cooling system filter.