If you have an HVAC system and have sourced replacement filters, you are likely to have come across the term MERV rating. This rating system is an important factor in determining the efficiency and effectiveness of the filter.
What is a MERV Rating?
MERV stands for Minimum Efficiency Reporting Value. It is used as a measurement for how effectively the filter can remove particles of debris and contaminants from the air passed through it. The scale of MERV ratings range from 1 to 20, with higher ratings representing greater efficiency.
Unfortunately, choosing the right filter is not simply a matter of picking one with a high rating. The highest rating is not always beneficial or necessary for the specific features of your home. To choose the right filter, you will need to learn a little more.
Filter Pore Size:
The MERV rating is also used to represent how fine each of the pores is in the filter. A lower score tends to mean that the filter pores will be larger. This means that a larger amount of small particles will be able to pass through the filter more easily. Unfortunately, this means that these particles will be able to continue to circulate around your home when your air conditioning system is turned on. When you choose a filter with a higher MERV score, it means that the pores are finer, and more particles will be removed from the air in your home.
Choosing the Right Filter:
Most domestic air conditioning units and systems are supplied with a filter rated at between 6 and 8 MERV. This level of filter can do a reasonable job of filtering airborne particles and allergens from the air inside your home. Most experts recommend that you replace this filter with one rated at 10 or more MERV. This is more likely to remove allergens and smaller particles of airborne debris. Filters with a MERV rating of 16 or over are usually used for clinics, hospitals and other facilities which require sanitized air to protect those with vulnerable health conditions.
While a higher MERV rating may sound like the best choice for your home, if you choose too high a rating could actually compromise the energy efficiency of your system and increase your utility bills. This is due to the central air system needing to work harder to push air through the filter. Generally , it is only recommended to have a higher MERV rating on your filter if you have elderly or young family members in the household more susceptible to poor air quality. Additionally, if there are an allergy sufferers or those with pre-existing medical conditions such as emphysema who may be affected by airborne contamination, you may benefit from a higher rated filter.
If you are interested in achieving better air quality, there are more economical and efficient options. These include options such as UV treatment and biocide filters. These systems can be conveniently attached to existing systems, removing stress from your system filter, while adding in another layer of air quality purification.