The boiler owner's manual will specify the best MERV rating for your furnace and, in general, filters with a MERV rating of 6 to 9 should be changed every 90 days, while those with a MERV rating of 10 to 12 should be altered every 60 days. A general rule for pleated air filters (such as those manufactured by FilterBuy) is to switch them out every 90 days. As the filter captures more dirt, dust, and allergens from the air, its efficiency decreases. To find out if you should replace the filter more often, read on. Filters that usually last 90 days should be changed every 30 days during the peak summer and winter months.
This is when HVAC systems are running at their maximum capacity and therefore require maximum efficiency to keep running smoothly. A dirty air filter restricts air flow, leading to poor air quality, higher energy bills, and eventually causing the system to fail over time. If you're going through a cold winter and the system is in constant use, you should consider replacing the filter more often than every 3 months. The basic recommendation for replacing oven filters is every 3 or 4 months in the case of the MERV 8, every 6 months in the MERV 10 and 11, and every year in the case of the MERV 16. It's not uncommon to find a 20-year-old oven that's been wearing the same one-inch filter for 20 years and the fan wheel is covered in dirt. The longer the filter is in place, the more dirt, dust, and allergens will be trapped, clogging the filter and reducing its efficiency.
The good news is that it's relatively easy to determine if the filter needs to be changed or not. However, people with allergies who have respiratory sensitivity may want to use a filter with a higher MERV score. The only type of filters that capture allergens and spores are HEPA, or high-energy particulate air filters. Filters with higher MERV values trap small particles more effectively than filters with lower MERV scores. As air moves through a building's air conditioning system, air filters trap and accumulate large and small particles such as dust, allergens, and microorganisms.
You might think you need to change the one-inch filter in sixty days when in fact you have a four-inch media filter that doesn't need to be changed yet. Determining how often you should change your air filter will depend on where you live, the time of year, the filter material, and the efficiency of the filter you select. HVAC technicians would be more than happy to do the dirty work and replace a dirty filter with a similar or more expensive one. Ovens and air conditioners in smaller homes need to pump less air for the same number of temperature changes which can mean less frequent filter changes. The multimedia air filter is a four-inch filter that usually doesn't need to be replaced for approximately 6 to 12 months.