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Type of Air Filter

What Type of Air Filter Should I Use in My HVAC Unit?

Choosing the right type of air filter for your HVAC (Heating, Ventilation, and Air Conditioning) system is crucial for maintaining indoor air quality and ensuring the efficient operation of your unit. With numerous options available, making the right choice can be daunting. This article aims to simplify the process by explaining the different types of air filters, their benefits, and how to select the best one for your needs.

Choosing the Right Type of Air Filter for HVAC Systems

An HVAC system is essential for creating a comfortable indoor environment by regulating temperature and maintaining air quality. The air filter is a critical component of this system, as it traps dust, pollen, pet dander, and other airborne particles, preventing them from circulating throughout your home. Selecting the correct type of air filter for aircon enhances indoor air quality and extends the lifespan of your HVAC system by keeping it clean and efficient.

Types of Air Filters

Several types of air filters are available, each with its advantages and disadvantages. Understanding these options will help you make an informed decision. LS Aircon Servicing Singapore, with services like aircon installation, chemical wash, chemical overhaul, etc., gives some valuable tips for choosing the right kind of air filter for your HVAC system. 

Fiberglass Filters

These are the most basic and affordable options. Made of thin layers of fibreglass, they are designed to protect your HVAC system by trapping large particles like dust and debris. However, they are not very effective at capturing smaller particles that can affect indoor air quality. Their main advantages are cost and availability, but they need frequent replacement every 30 days.

Pleated Filters

Made from polyester or cotton paper, these filters have a folded design to increase the surface area. This allows them to capture more particles and improve air quality compared to fibreglass filters. They offer higher filtration efficiency and a longer lifespan but can be more expensive and may restrict airflow if not replaced regularly.

Type of Air Filter for HVAC

Electrostatic Filters

These filters use static electricity to attract and trap particles. Available in both disposable and washable versions, they are more efficient than fibreglass and pleated filters, making them a good choice for households with pets or allergies. While effective at capturing small particles, they can be more expensive initially, and washable versions require regular cleaning.

High-Efficiency Particulate Air (HEPA) Filters

HEPA filters are designed to capture at least 99.97% of particles as small as 0.3 microns, including dust, pollen, mould, and bacteria. They are commonly used in environments that require high cleanliness levels, such as hospitals and laboratories. Despite their superior filtration efficiency, they can be expensive and may require modifications to your HVAC system due to their density, which can restrict airflow.

Washable (Reusable) Filters 

Made of durable materials, these filters can be cleaned and reused multiple times, offering a cost-effective and environmentally friendly option. They require regular cleaning and maintenance; their initial cost is higher than disposable filters. Additionally, their filtration efficiency may decrease over time.

Activated Carbon Filters

Designed to remove odours and gases in addition to trapping particles, these filters contain a layer of activated carbon that absorbs pollutants like smoke, cooking smells, and volatile organic compounds (VOCs). They effectively improve indoor air quality by removing odours and gases but are more expensive than standard filters and may need to be replaced more frequently depending on the level of pollutants.

Factors to Consider When Choosing an Air Filter

When selecting among different types of air filters for your HVAC unit, consider the following factors to ensure you make the best choice for your home and system:

Filtration Efficiency

An air filter’s effectiveness is measured by its MERV rating, which ranges from 1 to 20. Higher MERV ratings indicate better filtration efficiency. However, filters with very high MERV ratings can restrict airflow and may not be suitable for all HVAC systems. A filter with a MERV rating between 8 and 13 for most residential applications balances filtration efficiency and airflow.

Airflow Restriction

While high-efficiency filters are better at trapping particles, they can reduce the efficiency of your HVAC system by restricting airflow. This can lead to increased energy consumption and wear on the system. Choosing a filter your HVAC system can handle without compromising performance is essential.

Air Filter for HVAC

Filter Lifespan

Consider how often the filter needs to be replaced or cleaned. Disposable filters, such as fibreglass and pleated filters, typically must be replaced every 1 to 3 months. Washable filters can last for several years but require regular cleaning. Check the manufacturer’s filter replacement or maintenance recommendations to ensure optimal performance.


The cost of air filters varies widely. While cheaper filters, like fibreglass, have a lower upfront cost, they may need to be replaced more frequently. Higher-end filters, like HEPA and electrostatic filters, have a higher initial cost but offer better filtration and a longer lifespan. Consider both the upfront cost and the long-term expenses when making your decision.

Specific Needs

Your specific needs, such as allergies, asthma, or the presence of pets, should also influence your choice of air filter. High-efficiency filters like HEPA or electrostatic filters are recommended for households with allergy sufferers or individuals with respiratory issues. If you have pets, a filter with a higher MERV rating or one designed to capture pet dander is ideal.


Selecting the right type of air filter for your HVAC unit is essential for maintaining good indoor air quality and ensuring the efficient operation of your system. You can make an informed decision about air filters by understanding the various types of filters and considering factors such as filtration efficiency, airflow restriction, filter lifespan, cost, and your specific needs.

Frequently Asked Questions

Each rating indicates the effectiveness of a filter. A higher MERV rating signifies greater filter efficiency.
The primary function of this filter is to shield the interior of the unit from dust and other airborne contaminants, such as hair, pet dander, and fibres. As air flows through the filter, these particles are trapped, preventing them from entering and affecting various system components.
Yes, the more expensive air filters are generally more effective.