Perhaps the most important thing you can do to protect your HVAC system’s components is to maintain its means of air filtration. In other words, regularly replace or clean the system’s air filter.
It’s a simple task but can quickly become complicated due to the range of choices you have before you. What are the best filters for HVAC? What makes a good air filter? We are here to help you find the answers to these questions and more!
The first thing you will want to know is that there are different types of air filters. There are different types because several factors are present for high performance.
An air filter has two goals to accomplish. The primary goal is to prevent particles from entering the system and causing damage. The secondary goal is to improve indoor air quality.
These two factors alone are significant contributors to the fact that there are different types of filters. Keep in mind, HVAC systems aren’t all the same. They have different designs, use various components, and have different abilities. In short, a filter that has excellent air purification qualities can restrict airflow and may not be compatible with your system.
The budget is another contributor to filter selection. There are much more affordable options that offer basic function, high-dollar filters that provide superior function, and filter that land somewhere in between. Below are the types of filters that are available for typical residential HVAC systems.
- Fiberglass: The most basic filter types, and often the most affordable, rely on a thin fiberglass element. It is typical for these filters to produce the best airflow but the least amount of filtration. These types of filters typically have a MERV rating of 1 to 4 but may even be listed as “unrated.”
- Pleated Media: Pleated media filters are what you, as a homeowner, are most likely to select. The pleated media provides more surface area of the filter to capture debris and pollutants, increasing indoor air quality. These filters typically provide MERV ratings of 5 to 13, making it very easy to find this type of filter that best balances the needs of you and your system.
- Reusable: The filter types mentioned above are disposable. That means you will regularly need to replace them to keep the system at max efficiency. Reusable filters are an alternative option. They can offer the same level of performance as other filters but only require regular cleaning. These filters do come at a higher cost upfront, but are generally more affordable in the long run.
What Is MERV rating?
Now that you know the different types of filters, we can move onto the MERV rating system. MERV stands for Minimum Efficiency Reporting Value. In simple terms, it refers to the filter’s ability to filter out pollutants; the higher the MERV rating, the higher its ability to do so.
Filters with higher MERV ratings are tighter woven and will only allow smaller particles to pass through. As the weaving of elements becomes tighter, it will also create higher air resistance.
High resistance can lead to several issues. In extreme scenarios, they can lead to the furnace overheating, evaporator coils freezing, and will almost always cause strain on fans that must move the air. This is why higher MERV ratings aren’t always better.
You will also want to be aware that filters with higher MERV ratings typically need to be replaced more often. This is because they are trapping more particles and will, therefore, become clogged at a much quicker rate.
MERV ratings are listed on a scale from 1 to 20. In your home, you’ll want to aim for a filter with a MERV rating of 5 to 13. Filters in this range will have little impact on airflow but can still filter out allergens, dust, and other debris that will diminish indoor air quality.
Does price matter?
It is commonplace for a price to be an indication of a product’s quality. However, when it comes to air filters, it shouldn’t always be a scale you reference. A filter that is ten times the price of another may not always be the most effective option.
Higher MERV ratings and more costly materials, such as pleated media instead of fiberglass, will drive up the price. However, these characteristics are more relevant to function than a dollar amount. Therefore, you will want to ignore pricing until you can narrow down your selection to filters that suit your needs.
Does this mean you can ignore price altogether? No, mainly because this is a regular expense, and you also need to select an option that fits into your budget. But here again, how often a filter is replaced and how much it will cost you often comes down to the filter design.
This is why you may want to consider a reusable filter over disposable options. These HVAC filters use carbon elements, stainless steel, and other materials that are more expensive upfront. However, they only need to be washed every month, not replaced, making them more cost-effective over the years.
Does brand matter?
The brand you select does matter. This is because different manufacturers will have access to different materials and designs that will impact the filter’s overall ability to perform. Brand selection will also ultimately determine the price point of an air filter.
Does this mean you must invest your money in the highest rated or flashiest brand? No. It’s more important to find the filter that will suit your needs. Like price, you can base your decision on brand after you’ve found said filter.
What about HEPA filters?
You may have heard of HEPA filters and their superior filtration abilities. You may even be considering one for your home. It certainly is possible, but it is not as simple as using one in place of a typically residential-grade air filter.
High Particulate Air (HEPA) filters typically have a MERV rating of 16-20, which can remove viruses and virtually any other type of particle from the air. These filters are used in hospitals, laboratories, and power plants because of the utmost importance of air purification in these settings.
If you have a respiratory issue or other medical condition that requires high-levels of air purification, it may be worth tailoring your system to accommodate a HEPA filter. Otherwise, the expense may not be worth it.
Are the filters universal or do you need a size?
You will need to know the size to select the right air filter. Many times, you will hear residential air filters referred to as 1-inch filters. This is an essential bit of information but only refers to how deep the filter is.
You will also need to find the width and length of the filter. Something such as 16-inches x 25-inches x 1-inch is typical. The size is often printed on the old filter, but can easily be found with a tape measure.
How often should I replace the filter?
How often a filter needs to be replaced is subjective to a few factors. Most filters are rated to last 3-months, but this is hardly the case. Pollen, pet dander, and dust all effect filter life. In most homes, the filter must be replaced once a month for the best results.
So what is the best filter? That depends on your existing system and your demands. We find Lennox to have an extensive line that has offerings that offer most homeowners. However, we do understand that there are exceptions.
We do encourage you to do the research and find the filter that best suits your needs. However, a consultation with an HVAC technician can help you quickly find the filter that will best serve your home HVAC system.