Most times it is hard to know what air filter to choose. You hear, "Well this air filter is just as good as this one" all the time. Well here is the difference between them.
Air filters are judged by there MERV ratings. What does MERV stand for you may ask. Well, MERV stands for minimum efficiency rating value. The higher the MERV rating the more airborne particles it keeps out. As you can see MERV rating 6 keeps out lint, household dust, and pollen. Higher MERV does not always mean better though. Higher MERV can mean less air flow which causes your unit to work harder. In turn, makes the units efficiency go down and it can cause harm to your unit. What we always recommend here at Stafford's Heating and Cooling is to use a MERV 6 or MERV 8 for the best air quality for your home or business with less risk of dropping efficiency and causing major expenses in the future.
With all of that being said, the filter has to be changed regularly no matter what filter being used. With a MERV 6 or 8 we would recommend 2 months at the least. Not changing your air filter can result in air flow declining, due to particles filling in the surface area of the filter and not allowing passage. This will cause your unit to work harder, bills to go up, and possibly a shut down of your unit.