Do you know your (HVAC) System Filters and Furnace Filters
How are HVAC/furnace filters rated?
There are several commonly used filter rating methods. These include the Minimum Efficiency Reporting Value
(MERV), Filter Performance Rating (FPR), Microparticle Performance Rating (MPR), and others. MERV is based
on a national consensus standard. The FPR and MPR rating methods are proprietary. For all rating methods, the
higher the filter rating, the higher the removal efficiency for most particle sizes.
How do I choose an HVAC/furnace filter that will be most effective at removing small particles of greatest
health concern (PM2.5)?
Use the highest-rated filter that your system fan and filter slot can accommodate. Filters with a MERV of 13 and
above are required to demonstrate at least 50% removal efficiency for the smallest particles tested.
This is an example of a label from a portable air
cleaner. Used with permission from the Association of Homes Appliance Manufacturers (AHAM).
Guide to Air Cleaners in the Home 7
How do I know if my system can accommodate a MERV 13 filter or higher?
Most furnaces and HVAC systems can accommodate a MERV 13 filter without creating equipment problems,
provided that the filter is replaced frequently. Sometimes it can be difficult to tell whether a system can use a higher efficiency filter since HVAC systems are not commonly labeled with any filter recommendations. To be certain a filter will work with your system, consult a professional HVAC technician. The technician can determine the most efficient filter that your system can use. An HVAC technician can also modify the system to use a higher efficiency filter. Call us today at 540-295-6697
How can I tell if the filter is the right size for my furnace/HVAC system?
Filters commonly come in thicknesses of 1 to 5 inches, with a variety of lengths and widths to match common sizes
of filter frames in furnaces and HVAC systems. Make sure the filter fits snugly so air does not leak around the filter and you do not have to bend or crush the filter to make it fit.
How often do I need to change my filter?
Replace filters according to manufacturer’s recommendations. Many factors can affect how quickly filters get dirty. Manufacturers typically recommend replacement every 60 to 90 days. If you notice that filters appear heavily soiled when you replace them, you should consider changing them more frequently.
What if I have a window air conditioner or a wall-mounted “ductless” air conditioner?
Most window air conditioners and wall-mounted units are intended for temperature control rather than air filtration. These units typically have limited filtration intended to keep the inside of the air conditioner clean rather than remove fine particles from the indoor air