Is Your Air Filter Too Efficient?

All residential air conditioning and heating units use filters to help keep debris and small particles from getting sucked into the unit and increasing the need for more frequent maintenance.

How Do Filters Work?

The operation principle of an air filter is elementary. It is a device made of a mesh of fibers that prevents particles from entering your AC unit. They come in a wide variety of types, sizes, and filtering capabilities.

Filter strength is measured by the efficiency with which it keeps particles out. The technical term for this metric is the minimum efficiency reported value or MERV. The higher the MERV rating, the more efficient a filter in keeping even the smallest particles. Regular window AC units have a MERV rating of 2. A filter with a rating of MERV 16 can stop a lot of pollutants, even smaller than those that are smaller than 0.1 microns.

When shopping for an air filter, one crucial thing to check is the MERV rating.

Common Types of Air Filters

Fiberglass Air Filters

These are disposable filters that usually have the lowest MERV rating. They are ineffective at keeping pollutants out as they will only stop large particles. They are mostly used to trap debris and dust. However, they very affordable, making it a popular choice among many. Most systems are designed around using these types of filters, and they are readily available at the big box hardware stores.

Pleated Media Filters

These filters have a MERV rating that often lies between 5 and 13. Some can keep out mold spores and dander, among other things. The pleat designs are meant to enhance its filtering efficiency as well as increase its area. Looking at the ratings, this filter's effectiveness is still low, but it does not offer much airflow resistance.

HEPA Filters

HEPA Filters offer optimal protection from airborne particles. They can keep out small microns such as smoke and bacteria due to their high MERV ratings that fall between 17 and 20. The catch with using these filters is that they require a lot of work to install them, and experts might have to modify your system to fit one.

Reusable Filters

These filters are notable options for those that do not want to keep replacing and throwing out the old filters, as you can wash and reuse them again. However, you should ensure that they are dry before installing them as they can grow mold and mildew. They can also require a higher amount of power to pull the air through them.

Is It Advisable To Pick A Filter That Is Too Efficient?

Well, that depends on what efficiency you are talking about. If it is highly efficient with airflow... it probably isn't efficient with filtering out contaminants. Airflow moving through the filter too easily or not easily enough can tax the AC unit in different ways and cause problems.

The best filter should be the most efficient filtering particles that also works well with airflow in your system. It is essential to look at some of the other devices that work with the filter.

An efficient filter has a tight mesh needed to keep even the smallest pollutants out. However, the disadvantage of this is that the tight mesh restricts the amount of air going into the system. The blower in your fan needs this air, lest it starts malfunctioning. Most HVAC systems have specifications on the recommended MERV rating that the blower can handle, and it does not go over MERV 12, except for the complex and high-end units.

Reduced airflow in your unit can be the start of a series of problems. First, the reduced airflow will increase the air pressure in the ventilation system. This will move to damage the ducts, and it can extend to the AC and heater. You will feel these effects in the house as the place will be very uncomfortable and devoid of enough air. If you sum all this up, you will see that the high-efficiency filter will beat the logic behind the role it is supposed to play. Reduced airflow in your home will cause poor air quality, a problem that you tried to solve in the first place.

Which Is The Right Filter For You?

Most HVAC systems are suited to filters with low MERV rating, and it is vital to get this right, as you can damage your unit if you pick the wrong filters. There is a delicate balance between the efficiency you desire and the capability of your system that needs to be achieved. If you are unsure, which air filter to use, ask us to come out and take a look and we will recommend the best options for you.