Allergies are quite common, especially when seasons change. When humidity levels fluctuate or when there is a lot of dust in the air, you may be prone to sneezing, coughing, or a runny nose. It is possible to stay indoors and hope that your allergies can be brought down to a minimum. But you can still have allergies from the air that is circulated by your HVAC system. You are not allergic to HVAC air as such, but to what exists in that air- like dust, mold, pollen, pet dander and other contaminants.
Air filters are a good way to purify the air you breathe indoors. But not all filters help do the job.
Here is what you need to know about air filters.
1. HVAC filters protect the equipment, not you
It is a common misconception that air conditioner and furnace air filters trap allergens and contaminants. That is not the objective of HVAC filters. They are meant to keep dirt and dust out of the equipment so that it does not get damaged. While they can filter some amount of dust, they are not useful for removing tiny particles out of the air you breathe. You need special filters for that, which can help you stop coughing and sneezing.
2. Paper filters do not suffice for trapping allergens
Large dust particles that accumulate on the motor or fans of your air conditioner or furnace are trapped on the paper filters inside the unit, to ensure that the system runs smoothly. These filters are not good enough to filter contaminants like mold, bacteria or pollen that cause allergies. These allergens are so tiny that they can easily pass through the fibers of paper filters.
Air filters that are specially designed to combat allergy causing particles are called “high energy particulate air filters” or commonly, HEPA. These are made of densely packed glass fibers instead of paper.
3. There are various HEPA filters available; not all are alike
Any HEPA filter will work to trap allergens in the air, but for higher efficiency, you need to check the MERV (Minimum Efficiency Reporting System) rating for HEPA filters before purchase. HEPA filters are given this rating based on how well they trap particles of different sizes. MERV rating ranges from 1 to 12 and a HEPA filter with a MERV rating that is 10 or higher is most efficient in keeping allergies at bay.
4. Air filters need to be changed regularly
A slight downside to HEPA filters is that they need to be changed more frequently than ordinary paper filters. Depending on your geographical location and the season, you may have to change them once every month. HVAC technicians can guide you about HEPA filter usage and frequency of change.
5. HVAC cleaning is important
It is not enough to just install additional air filters. If your HVAC system is not cleaned and serviced regularly, it will collect more dirt and dust, and even extra filters will not be able to keep allergens out of your indoor air in your Bay Area home.