An air filter is an essential component of an HVAC system, designed to clean the air as it circulates through a home. These filters come in a variety of shapes and sizes, from disposable one-inch filters to washable whole-house air filters. Air filters are not optional, as they provide a first line of defense against larger objects that could cause damage or present a fire hazard. Clogged air filters are the leading cause of HVAC system failure, so it is important to replace them regularly.
Air filters are designed to capture large particles, dust and debris before they enter the air conditioner. They should not be confused with air purifiers or indoor air quality systems, which remove harmful particles and chemicals from the air. If your home doesn't have central heating or air conditioning, portable air filters are the most practical option. Portable and whole-house filters trap dust, pollen and more to clean air and improve indoor air quality.
When there is sufficient airflow, the air passes through the coils of the indoor evaporator and that cold energy is drawn from the coil and transferred to the house through the ductwork. For this reason, it is very important that you keep the filters of your heating or cooling equipment clean. Smaller contaminants, such as germs and bacteria, require a specialized air filter and UV lights, as the air filter is not designed to remove them. Experts say that at home you can realistically expect a HEPA filter to capture about 80 percent of those particles.
Like any filter, the frequency of replacement is determined by the factors that contribute to air quality. Disposable filters normally last from 1 to 6 months while washable air filters can last up to five years. Due to its huge surface area, there is no need to change a filter for the whole house so often.