07 Apr 95% Air Filter, MERV-14, MERV-15, or MERV-16 – Yes?
Oh MERV, if there were any clearer reason why you are going to be replaced by ISO 16890, it is the confusion of 95% air filters. A still common specification for final filters in hospitals the 95% filter could refer to MERV 14, MERV 15, or MERV 16 high efficiency air filters under ASHRAE 52.2/MERV Here’s Why:
MERV 14: Is still occasionally referred to 95% filters, becasue under 52.1 (which was removed in 1999) they were called 90-95% What has allowed this to continue is some of the low-end filter manufacturers still label the filters as 90-95% instead of using the rating system that has been in place for nearly 20 years. Using the 90-95% label on these high efficiency air filters is mis-leading as the fine particles are only filtered at 75% or better.
MERV-15: Not a common filter efficiency, MERV-15 will sometimes be called a 95%+ filter as that was it’s label under 52.1 This filter tends to get overlooked as it is between two very common high efficiency air filter values and although the static pressure is more comparable to 14 than 16, and the pricing is typically not too much more than 14, it is a nice option to get a little boost in filter efficiency with little off-setting drawbacks.
MERV-16: This one gets confusing. Because under 52.1 this was referred to as a 99% high efficiency air filter but these filters are also commonly tested under the DOP method instead of the MERV method and are then labeled as 95% DOP. There are differences in these test methods but it seems that the industry just looks to the side and has accepted that 95% DOP can be equal to MERV-16 on the baisis that the DOP method looks only at 0.3Î¼ particles and since it is 95% efficienct there it is assumed that the 95% threshold established throughout the rest of the particle size ranges in the MERV table carries through.
HEPA vs High Efficiency Air Filters: As a quick side-note to summarize these filters, there are many people throughout the industry that call these higher MERV filters “HEPA” filters – and they are not. HEPAs are tested under a completely different test method, are typically a different size (24x24x11.50 exact vs 24x24x12 nominal) and HEPA filters are also defined by IEST standards.
So what 95% filter do you need? Take a look at the chart at the top of this post and compare that to your requirements, or if you’d like our opinion we will be happy to assess your application and let you know what we think – Start by clicking here to contact us!