Furnace Filters

Furnace filters ensure that the air you breathe in is clean, fresh and free from pollutants.

Originally, furnace filters were designed to protect the furnace and fans. But now with the importance of air quality, it's being used with other equipments. Today it is being used in the HVAC (Heating, Ventilation and Air Conditioning) industry. Here are some of the other types of furnace filters.

Clean air is what all people want inside their homes. According to U.S. EPA indoor air is 2-5 times more polluted than outdoor air. The average person inhales about 18,185 liters of air each day. With this, the person breathes 1,120,000,000 particles of dust or microns.

• Disposable fiberglass filters

These filters are the least effective and cheapest units. They are designed to block large dust and particles only. This means smaller particles are not filtered. They are used to protect the furnace and placed in a cardboard frame.

They can filter about 2% of sub micron particles. They are typically installed in the ductwork of the home system.

• Pleated "allergy" filters

They are 35 to 50% efficient when it comes to filtering large allergens like pollen or dust. They are made of denser mesh material. They are better than flat filters. Most are made of electrostatically charged fibers that attract small particles. They cost around $5-$15 each and last for 3 months.

On the other hand, high standard units cost around $250 to $450. The pleats give the furnace filters more media, or surface area, where particles can be captured. Thin pleated filters can filter about 11% of sub micron particles and 25% in deep pleated. Some filters are sold pleated and electrostatic at the same time.

These filters produce 1 inch, 2 inch, and 4-6 inches deep materials. But air conditioners and heaters are 1-2 inches mostly. They usually have a MERV 5 rating.

• HEPA filters

High Efficiency Particulate Air filters are high standard units. They are used in hospitals, research facilities, and electronic laboratories. These places specifically require cleaner air. They block air particles but also blocks air flow.

They can filter about 2% of sub micron particles. They are also used in HEPA vacuum cleaners and HEPA air cleaners. They are advisable to be used by asthma sufferers.

They are similar in design to standard pleated air filters. But they have more pleats per inch to trap the smallest particles. They were developed by the Atomic Energy Commission during World War II. They were created to remove and capture radioactive dust particles from the air. They were designed to protect the human respiratory system.

They consist of a core filter that is folded over corrugated separators to strengthen core. They form the air passages between the pleats.

• Activated Carbon Air Filter

They are known as charcoal filters and are an alternative to media air filters. They are installed together with the regular filter pads. They are used for removing cigarette smokes, chemical and other odors. It removes the undesirable smells in the house. They are also available in panel filters but not as effective as the others.

Factors to Consider in Choosing a Furnace Filter

o filter dimensions- length, width and thickness especially on replacement filters
o filter maintenance regularly for equipment's longer life
o additional cost to electric bill for the use of furnace fan regularly
o special conditions of family members e.g., asthma or lung diseases
o efficiency of filters in terms of MERV rating