A typical residential HVAC system moves over 1,000 cubic feet of air through the ductwork every minute. All of it passes through your air filter. Optimum system airflow is one of the most critical parameters in a heating and cooling system. If the filter’s dirty or deteriorated—or wasn’t the right type to safeguard your indoor air quality in the first place —you may notice increased operating costs, contaminated air, and even damage to furnace or A/C components. Choosing the right filter and changing it regularly are vital for system efficiency and performance.
Most HVAC air filters are slide-in filters that install in a slot in your return duct, near the blower. Filters range from standard fiberglass panel filters to higher efficiency pleated filters. Fiberglass filters generally represent the least expensive option and are least efficient at removing airborne particulates. Typically, they are considered “throwaway” filters by most HVAC experts. Fiberglass filters are often provided by the manufacturer as original equipment on a new system simply to protect moving parts like the blower from dirt and dust—not protect your indoor air quality. Most people quickly upgrade to a pleated filter.
Pleated filters are composed of cotton or polyester fabric, pleated to greatly increase the surface area of the filter media, thus increasing filtration efficiency. These filters are at least 3 to 4 times more efficient than fiberglass filters at removing airborne particulates. They improve indoor air quality and, unlike fiberglass filters, don’t promote the growth of mold and bacteria inside the filter media itself.
MERV (minimum efficiency rating value) is a scale from 1 to 16 that rates filter efficiency. The higher the MERV rating, the better it removes airborne particulates. Filters with a MERV rating below 7 include cheap fiberglass examples and are usually inefficient. MERV ratings of 7 to 12 are most appropriate for household use. Filters rated 13 to 16 can restrict airflow excessively if not sized properly in residential systems. The key is to use the most efficient filter your system will be able to handle.
In Corpus Christi, contact CCAC for advice on choosing and changing the air filter in your HVAC system.
Our goal is to help educate our customers in Corpus Christi, Texas about energy and home comfort issues (specific to HVAC systems).
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