It depends on the type of filter and your expectations. Air filters have what's called a Minimum Efficiency Reporting Value (MERV) that goes from 1 to 20. The higher the value, the more efficient the filtering and the higher the price.
The cheapest filters are flat panel fiberglass, which have an MERV rating from 1 to 4. They can catch large particles in the air and will work properly for one to three months, depending on the amount of particulates in the home. But a low MERV rating means that the filter will protect the HVAC components more than it will actually clean the air.
Pleated Media filters have MERV ratings from 5-16, depending on design. These are more expensive, but will actually filter out smaller air particles more efficiently than fiberglass filters.
High Efficiency Particulate Air (HEPA) filters are the next step up. They have a MERV rating from 17-20. There are a couple of factors to consider with these filters. First, they are quite expensive. Unless someone in the home has health problems related to inhaling small particulates in the air, it may not be necessary to have a HEPA filter. Also, HVAC systems need a certain amount of air to flow into the system for it to work properly. If a filter is too efficient and restricts the air flow below what's needed, it could reduce the efficiency of the system or possibly even damage the components. Some HVAC systems may also require retrofitting before a HEPA filter can be used. If you are considering this option, let us examine your system and your home to ensure that the system would be a good fit.
Washable filters, also called permanent filters, are another option to explore if you are interested in cost savings over time. The filters can cost around $100, but if cared for properly they can last as long as the HVAC system itself. The two most important things to remember are to clean them regularly so they don't clog up and to let them dry completely before reinstalling them into the system and turning it on. A wet filter inside an HVAC system can end up blowing mold into the ductwork and into the home.
Every home is unique and so are its HVAC needs. Let us check out your system and our experts can determine what filter type is right for you and your home.