Dogs, Cats and Bowling Balls ($3 throw away)
This is your standard throw away filter or the reusable filter that comes with the furnace. About the only thing this filter will stop is dogs, cats and bowling balls. It is meant to protect the furnace, not your lungs.
Hog Hair
This is a standard cut to fit, usually a blue or green plastic filter. They come in 2 standard sizes and a roll.
Electrostatic (Flexible)
These are specially made for applications where noise can be a factor. Ceiling registers where the filter will moved and clank if it has a metal frame.
Electrostatic (Rigid)
These have either a metal or plastic outer frame and are meant to go into a filter box or the furnace itself.
1" Pleated
These are primarily used in commercial rooftop systems. They are throw away filters.
2" Pleated
These are primarily used in rooftop systems where people want a higher degree of air filtration. Useful for homes and businesses or schools.
4" Pleated
For the residential market for mild allergy sufferers.
5" Pleated
For the residential market for mild allergy sufferers.
1" 3M Filtrete
This is the first air cleaning filter on this list. Do not use it if you have air conditioning. If you only have a heater or furnace this is going to be the best low end filter you can buy.
2" 3M Filtrete
This is a step up from the 1" 3M Filtrete. It cannot be used in furnaces and must be used in filter boxes. It has more loading ability and less static pressure resistance than the 1" filter.
Electronic
Not in style anymore. Turns out that this filter is excellent for a few days and then starts to lose it's ability to clean the air. Snap, crackle and pop noises seem to biggest complaint with these filters.
IQAir-16 (Perfect 16 Merv Rating)
Unbelievable filtration with a media air cleaner. Does not produce any ozone and filters through a series of micro-fine pleated filter media that is unlike any other. This is recommended for allergy sufferers and those that are sensitive to ozone. This will deliver hospital grade air. This whole house air cleaner should be installed with new systems or system under going a retro-fit. It is large and will not fit in most upflow applications.
AccuClean (Trane CleanEffects)
Our tests show conclusively that this whole house air cleaning system is the best on the market. It does release some ozone, but the ozone amount is variable and can be turned down. this can be installed in most upflow and horizontal applications and comes with a 5 years warranty from the manufacturer.