ASHRAE help!!!

[zer0]

i am trying to purchase 85% efficiency filters for my AHUs at work. But the sales people from filters are keep giving me ASHRAE standard 52.1 certificate which says that MERV-13 are 85%, but according to ASHRAE 52.2 they are <75%. Is ASHRAE 52.1 still accepted by FDA etc?

Thanx

[breathe easy]

z
The 80-85% efficiency filter you are seeking is generally accepted as a MERV 13. The problem is the numbers are derived by totally different test methods. The 75% you are seeing in the 52.2 test is a percentage of particle capture by particle size. The 80-85% in the 52.1 test is a "dust spot efficiency" which is the discoloration of a "target" exposed to test dust on the downstream side of the filter.

The 52.1 standard has been "retired" which means it won't be accepted by the FDA.

For a review of the current ASHRAE filter testing situation see:

http://allergyclean.com/articles/?p=157

[zer0]

z
The 80-85% efficiency filter you are seeking is generally accepted as a MERV 13. The problem is the numbers are derived by totally different test methods. The 75% you are seeing in the 52.2 test is a percentage of particle capture by particle size. The 80-85% in the 52.1 test is a "dust spot efficiency" which is the discoloration of a "target" exposed to test dust on the downstream side of the filter.

The 52.1 standard has been "retired" which means it won't be accepted by the FDA.

For a review of the current ASHRAE filter testing situation see:

http://allergyclean.com/articles/?p=157

Breath Easy,

Thank you very much it does clear up lot of confusion. So in order to satisfy FDA we must use ASHRAE standard 52.2 MERV 14 for 85%

[breathe easy]

You can use a MERV 13.

[zer0]

You can use a MERV 13.

But MERV 13 is <75% for 0.3 micron particle, we are looking for 85% efficiency for that size particle, so MERV-14 would be a better choice right?

[breathe easy]

z
You need to read the article.

An 80-85% filter tested according to 52.1 has nothing to do with efficiency at 0.3 microns. If for some reason you actually need 85% efficiency at 0.3 microns, the only filter that will provide this is a true HEPA. The 85% you are reading off the ASHRAE 52.2 chart is actually an average for 4 particle sizes between 0.3 and 1 micron. A MERV 14 filter would generally provide less than 70% efficiency at 0.3 microns.