The general rule of thumb is that one air filter is needed for each air handler. Most homes, especially large ones with multiple HVAC systems, have more than one filter installed. They are usually placed near the oven or manipulator of the air conditioning system and return grilles. Typically, a home will have two air filters in its inlet holes.
In some cases, there may be more or less depending on the square footage of the house or apartment and the number of floors that must be supported by the central air system. When it comes to air filters, there are a few things to consider. Some air filters are supposed to survive up to six months, while others need to be changed monthly. The denser the air filter, the longer it will last.
In general, you can examine the thickness of the filter instead of the mark. You also need to take a look at the MERV rating. To replace an old filter, first remove it and clean the dust with a damp cloth. Then, when the area is dry, replace it with a new one.
If you have more people, pets, or clutter than most homes, you'll need to change filters more often. Also, while it's typical to see filters on the air handler, you can choose to place them in the return vents. Air filters typically have a MERV (Minimum Efficiency Report Value) that determines the type and size of contaminants against which the filter will act. It's questionable if it works the same way as a 2- or 4-inch air cleaner in terms of filtration efficiency when working with your central air system. As air moves through a building's HVAC system, air filters trap and pick up large and small particles, such as dust, allergens and microorganisms. The main difference between a whole-house filter and a regular one-inch filter is longevity.
Don't be surprised if this filter is incredibly dirty, as many homeowners forget or never knew they were there in the first place. From sizes to types, grades and more, here's everything you need to know about air filters. In general, most air filter manufacturers and HVAC companies recommend changing your air filter every 90 days or 3 months. If someone in your family suffers from mild to moderate allergies, you can put on a better air filter or change it more often. The MERV rating is a scale from 1 to 20 and evaluates how well an air filter can remove particles from the air.
They also generate less air resistance, which can help the HVAC system work more effectively and reduce wear and tear on components, including the fan motor. It's best to go with the information provided by your system manufacturer when it comes to how many HVAC filters you need for your home. This means that two 25x20x5 filters can have completely different sizes if they are made by different brands. Internet speculation that these filters cause its system to overload its fans is largely based on misinformation.