The general consensus among HVAC professionals is that you should replace your furnace filter every 90 days or every three months. However, that depends on the thickness of the filter. Thicker filters have more room to accumulate dirt and dust, so you don't need to change them as often. Thomas & Galbraith Heating, Cooling and Plumbing, of Ohio, recommends changing filters less than 2 inches thick every 30 to 90 days.
Three- or 4-inch filters can last 6 to 9 months, and filters up to 6 inches thick can be replaced once a year. However, experts suggest changing them once every 30 days if the air filter is made of fiberglass filters, which are of relatively poor quality. On the other hand, expensive pleated filters can work well if replaced once every three to six months. It is essential to have a clean filter to prevent dust from passing through the air conditioning system, where it can accumulate in the indoor coils of the air conditioner and reduce the efficiency of the unit. It consists of loosening the screws that hold the filter cover in place if it is located behind a ventilation grill or simply pulling the filter out of a slot if it is on the side of the oven.
Using an air filter with a MERV rating higher than that recommended by the boiler or air conditioner manufacturer can actually impair its performance. Air filters are electronic devices used in homes, offices, or any enclosed space to regulate temperature, collect dirt and allergens, and control humidity. Simply put, if the air is of poor quality both outside and inside the house, you'll need to replace the air filter more often. Your specific situation is unique, but most air filtration experts agree that furnace filters have an overall lifespan. However, some air conditioning systems have filters inside the return air ducts scattered throughout several rooms in the house. As air circulates through a building's air conditioning system, air filters trap and accumulate large and small particles, such as dust, allergens, and microorganisms.
While a filter with a higher MERV rating should last longer, it can also restrict airflow in your home. Air filters are usually made of spun fiberglass (the same that forms the insulation of the attic) or of pleated paper framed with cardboard for greater stability and rigidity. Invented in 1902 by Willis Carrier, air filters work by transferring unwanted components of air from indoor spaces to outdoor spaces. If you want a dog or cat that is hypoallergenic or that doesn't lose hair, you may not have to replace the air filter as much. Be careful not to confuse Honeywell oven filters with HEPA air filters for purifiers, which last much longer. So when should you replace your 16x25x4 air filter? The general recommendation is to replace it at least once every 90 days.
But if you let that time go by for a while, it depends on the thickness of your filter. Thinner filters need to be changed more often than thicker ones. Fiberglass filters should be changed every 30 days while pleated ones can last up to six months. Additionally, if you have pets or live in an area with poor air quality outside and inside your home, you may need to replace your filter more often.
