What Does The Merv Rating On Air Filters Mean

An Piece of cake Guide to MERV Ratings for Your AC Filter

June 3, 2013

When selecting an air conditioner, there are many frequently asked questions, at least ii of which relate to filtration. The first might exist what kind of filter is needed. Whether or not that question comes to mind, the other likely question is what does the MERV rating hateful that is on filter and what does it exercise.

What is MERV?

In the simplest terms, MERV measures how much matter passes through an air filter. MERV stands for Minimum Efficiency Reporting Value. MERV ratings are on a calibration of one to twenty depending on the minimum size of the particles a filter can be expected to capture:

A filter with a MERV rating of one to four captures particles greater than ten micrometers. This includes bugs, dust mites, and household droppings. Most window air conditioners autumn within this range.
A filter with a MERV rating of five to viii captures particles greater than three micrometers. This includes mold, pet dander, and aerosol sprays. This is the baseline for permanently installed residential air conditioners.
A filter with a MERV rating of nine to 12 captures particles greater than i micrometer. This includes well-nigh dust and common pollutants. Hospital laboratories and superior residential air conditioners autumn within this range.
A filter with a MERV rating of 13 to xvi captures particles greater than 0.3 micrometers. This includes bacteria, droplets from sneezing, fume, and most other sources of pollution. This level of filtration is used in patient and surgery areas of hospitals.
A filter with a MERV rating of 17 to 20 captures virtually all particles. This includes viruses and the finest particles of fume, grit, and other droppings. This level of filtration is typically only used in make clean rooms for the industry of electronics or scientific experiments.

What Level of Filtration is Needed?

As seen in a higher place, for a permanently installed residential air conditioner, the range is between v and twelve, which tin can seem rather large. In actuality, HVAC experts oft land that there is generally little noticeable difference in one case the MERV rating is greater than vii.

Ane gene that may change this is allergies or other health concerns. In that case, a filter capable of removing allergens would be desired and an HVAC expert should be consulted to determine the appropriate level of filtration to aid allergies and be advisable for your organisation.

Mod construction may as well create a demand for increased filtration. This is because
meliorate insulation and airtight construction reduces air circulation. Although this decreases leaks and therefore utility bills, it also means that fresh outdoor air is not coming into the home and indoor pollutants from cooking, cleaning, and other causes can build upwardly. The air conditioner filter may be the dwelling house's but filtration or ventilation organization and in that example, a higher rated filter will probably be desired.