unobjectionable furnace filter save Department of Energy and money , unpatterned and simple . Routinely change or cleaning the furnace filters from your domicile ’s heat and aura conditioning organization help the units run more efficiently and enjoy a longer life-time ( plus , it also meliorate your indoor strain quality ) .
Buthow often should you change furnace filters , and what should you do if they count unobjectionable when it ’s time to replace them ? What do these filters really do ? How can you order if they ’re knead ?
What Is the Purpose of Furnace Filters?
To change the temperature in your abode , your heating and atmosphere - conditioning system sucks in melodic line from a way , pulls it over coils to heat or chill it , then blows the temper air through ducts to the other room in your dwelling . The furnace filter , or air filter , is post at the point where tune is pulled into the organisation .
It traps airborne particles that get sucked in with the tune and maintain them from stymie the blower and congest up the coils . Clogged coils ca n’t heat or cool the air passing over them , and they may damage the arrangement .
So , the furnace filter help your heating and cooling scheme do its job , keep it run efficiently and protect it so it will last longer .
A decently sized , installed and functioning heating and air system circle the air in your home plate every hr . In the summons , it pull that air through the filter . Just how much the filter cleans the melodic line depends on the MERV rating of the filter .
Understanding MERV Ratings
MERV stands for Minimum Efficiency Reporting Value . MERV ratings indicate the size of particle that a filter can remove from the melody passing through it . MERVs range from 1 to 16 , with a higher phone number indicating a higher cleaning efficiency because it can trickle little particles out of the atmosphere .
Most filter will tell the MERV rating on the promotion . It betoken the size of particles , measured in microns , which a filter will capture . The higher the MERV rating is , the smaller the mote it can catch . To give you an idea of particle size [ sources : INDA , Howarth and Reid ] :
The brassy , 1 - inch ( 2.54 - cm ) chummy , disposable filter made of hugger-mugger fiberglass or natural fiber strands typically have a MERV paygrade of 1 but can go up to 4 .
Percentage of Particles Filtered
The MERV rating also indicates the percentage of particles the filter will remove from the air pass through it .
In general , a MERV rating of 6 indicates that the filter will enamor up to half of the particles in the air ; a filter with a military rank of 8 will pin 70 to 85 pct of airborne corpuscle it meet .
A rating of 11 or high stand for that the air pass through the filter is up to 95 percent sporting when it comes out of the filter than it was when it get going into it .
Pleated Filters
Pleated filters made of nonwoven , disposable fabric have smaller pores , and the pleats increase the control surface area of the filter so it can concord more particles than a flat surface can .
These filter have MERV evaluation of 3 and higher depending on the density of the cloth and the number of pleats [ root : INDA ] . Some are charged with static electricity to pull in and hold airborne allergen .
Filter Efficiency and Air System Performance
The particle catching efficiency in reality go up as the filter gets lousy ; buildup on the fibre reduce the initiative the air make pass through and allows the filter to becharm more mote .
But this is honorable only up to a sure point . The particle - removing efficiency of the dirty filter is inversely colligate to the energy efficiency of your heating and air system . A byproduct of houseclean the air is a restriction of the air - rate of flow through the scheme .
conceive about times you ’ve worn a debris mask while you work on a project . It ’s harder to breathe through the mask than it is if you are n’t wearing one .
If you upgrade to the HEPA ( high - efficiency particulate air ) mask that filters out particle as small-scale as 0.3 micrometer with up to 97 percent efficiency , it gets even harder to rend in enough air to keep you going [ source : Howarth and Reid ] .
The same is true of your heating and air organisation : The denser the filter , the harder the scheme has to work to pull in line . A clogged filter may cause your system to lead unceasingly , repel up your heating or cooling bills .
That ’s why it ’s important to check your filters at least monthly and change them when they get muddied .
What if My Furnace Filter Looks Clean When It’s Time to Change It?
According to Freddie Williams , an instructor of air - conditioning technology at Lanier Technical College in Oakwood , Ga. , high - grade filter are the most effective way to clean the airwave in your abode . But what do they look like when they ’ve done their job ?
When it ’s meter to change your filter — anywhere from one to three month after you instal a fresh one — it should look dirty .
" A build - up of dust is normally ostensible , " Williams say . " There should be hoary , ash-grey - looking material on the channel side of the filter . "
If your filter looks clean after it ’s been in place for the recommended time , here are some things you should check :
Your home environs and how often you execute the heat or air can also affect how quickly your furnace filter gets soiled .
If your home is well seal , you have no ducky , no dust - prone furnishing like carpet and fabric - covered furniture , and you sprinkle and vacancy every day , your furnace filter will have fewer airborne particles to collect . Also , the system only separate out the tune when it ’s running .
If you install a new filter but do n’t turn on the oestrus or air conditioning until a month or two later , the filter should still be relatively clean since the organisation has n’t been storm aviation through it .
This article was updated in conjunction with AI technology , then fact - fit and edit by a HowStuffWorks editor .
