One of the most common pieces of advice we give homeowners is to change the AC filter regularly to maintain the system’s efficiency. What most people question what “regularly” means. The answer is -- that depends.
It depends on the particles in your air. For instance, someone with allergies who lives in a high pollen area may need to change the filter more often than someone who doesn’t. But it also depends on the filter.
Each filter is rated by a minimum energy reporting value (MERV). It ranges from 1-12 in residential units. The higher the number on the filter, the more particles it will screen. Higher numbered filters trap more allergens and bacteria from entering the air but they are also more costly and will require more energy to pull air through them.
Types of AC Filters
Here are a few additional things you should know about the options out there:
Basic Fiberglass Air Filters
These filters come standard with most units. They are flat fiberglass panels with a MERV rating of between 1 and 4. Their job is to keep large particles from entering your AC system and affecting its efficiency. They do not improve the air quality in your home. They are disposable and cheap (about $2 a piece) and should be changed every 30 days, more often as the atmosphere and usage dictates.
Pleated Polyester Air Filters
A step up from their fiberglass counterparts, these filters are great dust trappers. They can remove up to 45% of airborne particles. They cost around $10 each and have a MERV rating of between 8 and 13.
Although these reusable filters seem like an environmentally-friendly choice, their low MERV rating (between 1-4), the maintenance required with washing and clean up, and their cost (around $20), make them an unappealing choice for most homeowners. If they are not dried well in between uses mold and fungi can grow, which can be circulated into the air in your home and then breathed in.
High-Efficiency (HEPA) Filters
These filters have the highest MERV rating (often between 14-16) and trap nearly 85% of airborne pollutants. They work well for people with air quality concerns but they create quite a drag on your unit, which may not be optimum for older ACs.
There is a wide range of filters on the market and while many people will go out and select the one with the highest MERV rating that is not always the best for their system. Many residential air conditioners are not designed to handle that sort of restriction in the air flow. If you have air quality concerns and an older unit, look for a MERV rating between 9-12. It will give you good air quality without impeding your system.
If you’d like to know more about the ideal air filter for your air conditioning unit contact us today at Easy A/C at 813-COLD-AIR (265-3247). We can take a look at what you have and give you an idea of what would work best for your home, area, and family.