Understanding MERV Ratings


As we keep hammering on about, it is important to have your air conditioning unit serviced and maintained to ensure that you extend the life span of the unit therefore getting more for your money. With winter probably the easiest time to do this as it won’t be in use here are some tips on understanding the MERV ratings that come with filters.

Not all filters are created to be equal and checking the filter has to be a priority, at least once a month. Overall a MERV rating is a measure of the filters performance and usually rate between 1 and 16 although in industrial scenarios they can reach 20. In short, the higher the number the better the performance meaning better filtration especially when there are a considerable amount of small particulates that the filters are capable of capturing.

For your home or office environment you should aim to have a rating between 7 and 13. Filters with this rating will remove dust and allergens efficiently as well as other particulates from the air supply. It also ensures that there is a reasonable life span of the filters as well as energy efficiency and it will also mean that your unit runs quieter due to less restriction for the air flow.

We have listed a couple of examples of the MERV rating so you can see the difference:

Filters with a rating of 7 are usually made of synthetic materials or cotton and filter particulates such as dust, mould spores, hair spray and pet dander’s.

Filters with a MERV rating of 9 have been designed for more superior air filtration. Pleated filters are usually 1-6 inches thick or box style filters are between 6-12 inches thick and will filter out lead dust, legionella and auto emissions as well as the particulates listed above.

The MERV rating actually takes into account the worst case scenario of its own performance therefore you can be safe in the knowledge that your filters are working well. The professional who will be servicing your unit will be able to tell you the rating that is best for your particular situation.