How do air filters help maintain good indoor air quality?

2 Types of air filters

The market offers many types of air filters, each with their own benefits and drawbacks. High-efficiency particulate air (HEPA) filters are mechanical filters that can remove 99.97% of particles that are 0.3 microns or larger, making them effective for capturing dust, pollen, mold, bacteria, and viruses; however, they are costly and require more energy and maintenance than other filters. Activated carbon filters are electrostatic filters which can adsorb gases, odors, and volatile organic compounds (VOCs) from the air; but they have a limited capacity and need to be replaced frequently. Ultraviolet (UV) filters are biological filters that use UV light to kill or inactivate microorganisms; but they do not remove particles or gases and may pose a health hazard if not used properly. Other types of air filters include ionizers, ozone generators, photocatalytic filters, and humidifiers - each of which has its own advantages and disadvantages - some of which may generate harmful byproducts or ozone.

3 How to choose the right air filter

Choosing the right air filter for your needs depends on several factors, such as the size and layout of your space, the source and level of contamination, the desired air quality, and your budget and preferences. The efficiency of the filter is measured by its minimum efficiency reporting value (MERV), which ranges from 1 to 20. Additionally, you should consider the type and size of particles, as different filters have different capabilities for removing different particles. The size of particles is measured by the micrometer (μm), with coarse particles being larger than 10 μm, fine particles between 2.5 and 10 μm, and ultrafine particles smaller than 2.5 μm. Lastly, airflow and pressure drop are important factors to consider when choosing an air filter; these are influenced by the type, size, and density of the filter media, as well as the frequency and quality of maintenance. Ultimately, higher airflow and lower pressure drop are desirable but depend on the design and capacity of the system.

4 How to maintain and replace air filters

Maintaining and replacing air filters regularly is essential for ensuring good IAQ and optimal performance of your ventilation system. If neglected, dirty or clogged filters can reduce airflow and efficiency, increase energy consumption and noise, and create a breeding ground for microorganisms. To ensure proper filter maintenance and replacement, check the manufacturer's instructions and recommendations for the type, size, and frequency of filter replacement. Typically, filters should be replaced every 3 to 12 months depending on usage and condition. Inspect the filter visually and physically each month or more often if needed; look for signs of dirt, damage, or mold on the filter media, frame, or seal. When choosing a filter, select one that meets your needs and fits your system; avoid generic filters that may not perform well or last long. It's also important to handle the filter carefully; wear gloves and a mask when removing or installing the filter. Dispose of the used filter properly in a sealed plastic bag; do not touch or shake the filter as this may release particles or microorganisms into the air. Lastly, clean the filter housing and surrounding area with a damp cloth or vacuum cleaner both before and after replacement.