The short answer is: no, they're not all the same. In fact, there are many different types of air filters available and choosing the right one can make a big difference in the lifespan of your HVAC system. If your air conditioning system is equipped or can be equipped with a thicker media filter, you're in better shape and have more filtration options. Since a media filter has a much larger surface area than a one-inch filter, you can use a MERV 11 filter, which is approximately eighty-five percent effective against mold spores and larger dust particles.
A multimedia filter can protect your equipment and improve indoor air quality without degrading the performance and efficiency of the air conditioning system. You may need to replace the filter more often if you have a few very furry pets, for example, or if you live in an area with a lot of air pollution, such as that caused by forest fires. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHARE) recommends a MERV 6 or higher. In fact, the City of Austin's Green Builder program recommends installing a 4-inch media filter in all new homes built in Austin.
“They inhale through the ventilation grilles in the living room and draw air through the ducts and through the heating or cooling source (whether it's the burners of an oven or the coil of a heat pump or air conditioner). That's why it's important to only use air filters with the MERV rating recommended by the HVAC system manufacturer. Make sure you install the new filter facing the correct direction; look for the arrows on the filter frame that indicate the direction of air flow. The MERV standard is primarily used to measure the performance of filters designed for forced air HVAC systems.
Both among industry professionals, there is a lot of confusion when it comes to the air flow of the central air conditioning system, air filtration and indoor air quality. Flat filters should be replaced every 3 months, or monthly if there are allergies, pets, or someone smokes. Your HVAC professional will install a small cabinet next to the boiler or air controller (on the air intake side) to hold the thicker filter. However, some air conditioning systems have filters inside the return air ducts spread over several rooms of the house.
