Air filters are simple but critical parts of every HVAC system. Effective filters can give you clean air and efficient system operations, while bad ones can leave you inhaling dirty air and paying sky-high energy bills. Since this makes learning about HVAC filters worthwhile, here are five of the most common types of air filters homeowners will encounter.
1. Fiberglass Filters
Fiberglass filters are the most common types of air filters. The layered fiberglass that makes up these filters can capture relatively large particles of dirt and dust, but they’re not as effective against smaller particles like pet dander or pollen. These filter types need replacing every 30 to 90 days.
They only have minimum efficiency reporting value (MERV) ratings of between 1 and 4, which means that they are rather weak filters. On the other hand, they are cheap and present little in the way of airflow resistance.
2. Pleated Filters
The mesh of pleated filters usually consists of either cotton or polyester, which gives them a larger surface area than fiberglass filters have. This results in MERV ratings for pleated filters that range between 5 and 16. Those with MERV ratings of 5 to 8 are the most common in residential buildings.
Pleated filters with MERV ratings of 9 to 13 can capture bacteria, viruses, and the tiniest particles with high accuracy, and those with MERV ratings higher than 13 exist most often in hospitals and laboratories. Filters with MERV ratings between 8 and 13 will be more than adequate at home, but remember that a filter with a higher MERV rating also has a greater chance of cutting off HVAC airflow.
3. UV Filters
UV filters are especially useful for those who wish to disinfect the air in their homes. As air passes through the mesh of the filters on these devices, they shoot ultraviolet light at the air using a special light bulb. That light kills any latent bacteria in the air, though you will have to remember to replace the bulb about once a year.
4. Electrostatic Filters
Electrostatic filters use electrically charged metal plates to improve indoor air quality (IAQ). They do this by changing the air around them with electricity. Since the filter plates have an opposite charge, all airborne pollutants that pass into the filter will stick to the plates.
You can wash and reuse electrostatic filters without having to replace them. However, they can be expensive, and installation will require professional service. Also, they may generate ozone as a byproduct, which may harm you if you have respiratory problems.
5. HEPA and ULPA Filters
High-efficiency particulate air (HEPA) filters are among the most powerful filters, boasting MERV ratings between 17 and 19. They are so powerful that standard HVAC systems cannot beat them without special modifications. They can remove 99.97% of all particles with diameters of 0.3 microns or more from the air.
Ultra-Low Particulate Air (ULPA) filters are the most powerful ones of all. They have MERV ratings of 20 and can remove 99.99997% of all particles measuring 0.3 microns across or larger and 99.999% of those measuring up to 0.12 microns across.
Since HEPA and ULPA filters are so powerful, you’re most likely to find them in professional or industrial settings where filtering out toxins from the air is essential, like laboratories or cleanrooms for the production of products like electronic devices, pharmaceuticals, and medical equipment. They can even remove viruses and fine carbon dust from the air. Only people with extreme sensitivity to allergies or respiratory issues use them in domestic settings.
The right filters can be a great help both to you and to your HVAC system. Our team of experts can tell you all you need to know about how to choose the right filters to maximize comfort in your home. Call Griffith Energy Services today and request our HVAC services.
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