The air filters in your home need to be changed or cleaned, depending which type you use, frequently. As they are designed to collect the dust and debris in the air, they eventually get built up, restrict the air flow in the central air system, which reduces the efficiency of the system as well as the quality of the air you breathe. Not only does changing the air filter make a difference in the system and the indoor air quality, but so does having the type and quality air filter. We at NY NJ AC Connection would like to take a moment to specifically talk about the MERV rating of the air filters.
What is Minimum Efficiency Rating Value (MERV)?
In order to give you the opportunity to compare the assortment of air filters available, an industry standard rating system, known as the MERV or Minimum Efficiency Rating Value was developed. Based on numerical value, the lowest efficiency starting at 1 and the highest efficiency ending at 20, MERV grades the filter on how well it captures and hold the debris as well as the specified size range.
How Are Air Filters Tested by ASHRAE?
The American Society of Heating, Refrigerating, and Air-Conditioning Engineers, commonly known as ASHRAE created MERV for the air filters efficiency. The ASHRAE Standard 52.2-2007 is a method of testing, designed for the general ventilation air-cleaning devices for removal efficiency by particle size. The standard 52.2 sets the testing protocols for reliable and consistency of filter performance on particles of nominal 0.3-10 micron in diameter. This indicates the filter’s performance is based on the particle size, ranging from 0.3 – 10 microns and the guidelines are also set for when the filter is first installed.
What MERV Rating Should I Use?
Smaller particles are captured and contained from the air with better quality filters that have a high MERV score. The lower the rating, such as MERV 1-4, remove the larger particle and are filters typically designed to protect equipment. When the average particle size efficiency from 3 to 10 micron is less than 20% for these values, the filters are generally used in light industrial and residential applications. To protect individuals or processes from airborne contaminants that could otherwise impact health and productivity the filter should have a MERV 5 – 16 score to remove finer particles; which are used in most cases.
MERV Rating Chart
Below you will find the basic MERV guideline for air filters.
MERV 1 – 4: Minimum filtration; used lightly in residential buildings.
MERV 5 – 8: Commonplace in commercial applications and ideally used in residential buildings.
MERV 9 – 12: Optimally utilized in residential buildings and ideally in commercial buildings.
MERV 13 – 16: Frequently found in hospital inpatient and general surgery as well as best utilized in commercial buildings.
MERV 17 – 20: Best used for clean rooms and pharmaceutical manufacturing.
Central Air Conditioning Services in Manhattan, New York
When selecting your air filters, we hope knowing the fundamentals about MERV helps. It is best to check the air filters monthly, and whether they need it or not, change every 3 months. Homes with multiple occupants, smokers, pets, and those with allergies and asthma should consider changing them monthly whether they need it or not. If you are due for maintenance or experiencing problems with the central air system, call the professionals of NY NJ AC Connection today and let our experts take care of your HVAC needs.