HEPA Filter Ratings

There are many types of air filters, but any filter that is labeled "HEPA" has a very specific rating. The HEPA standard states that a HEPA air filter must trap 99.97% of all airborne contaminants that are 0.3 microns.

This means that for every 10,000 air particles that are 0.3 microns, the HEPA filter will only allow 3 of them to pass through.

How Big is a Micron?

A micron is 1 millionth of a meter, or about 0.00003937 inches, which means there are 25,400 microns in an inch. This dot (.) on your computer screen is about 615 microns.

The human eye can see particles as small as 10 microns, and an optical microscope allows us to see things as small as 0.1 micron. Electron microscopes allow us to see things as small as 0.001 microns.

HEPA air filters are the most efficient type of air filter because they can trap most air particles including bacteria and viruses.

Other Types of Air Filters

HEPA filters are classed as a mechanical air filter. Other types of air filters include Electronic or Electrostatic Air Cleaners and Gas-phase Absorption Air Filters. The American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) has come up with a rating system for each type of air filter. This rating system is called Minimum Efficiency Reporting Values (MERV) and most air filter manufacturers now label their products with a MERV rating.

Typical disposable air filters are rated between MERV 1 and MERV 10, with the higher ratings indicating a more efficient air filter.

The HEPA standard exceeds the MERV specifications because they are the only mechanical air filter with an efficiency of 99.97% at 0.3 microns. This makes them at least 50% more effective than other types of mechanical air filters.

Comments

pragnesh
10 Mar 2007, 05:40

Really on this site you have mentioned very good information, I really appriciate your efforts.

My question is --- I want to know the gradation of filter because in pharmaceutical industries people are used to indentify the filter by grade like H 12, H 13, EU 12
I am requesting you please inform me regarding this grade and If possible than send me this grade with micron size

Thanks
Pragnesh Patel.

Mark
10 Mar 2007, 11:04

The H12 rating is for a filter with a 99.5% efficiency rating and H13 is rated at 99.95% efficiency with 0.05% penetration. The local value of H13 is 99.75% efficiency - so HEPA filters are comparable to a H14 rating which has a local value of 99.975% efficiency.

Labade Ganesh Sitaram
05 Apr 2007, 11:33

Dear Sir,

I requisted You pl. send EU standered for filter efficency

KIRAN kOTASTHANE
28 Apr 2007, 09:05

I requisted You pl. send EU standered for filter efficency alog with the comparison with other stansards

purvi
05 Jan 2008, 03:17

Dear Sir,

I requisted You pl. send EU standered for filter efficency
requisted You pl. send EU standered for filter efficency alog with the comparison with other stansards
also let me know whether hepa can be of efficiency below .3 micron

Indulal Acharya
08 Feb 2008, 02:11

Dear Sir,
I would like to know how to fix the size of hepa filters (i.e. 400 m3/hr.) Please let us have size calculation for suitable filters for Hepa by less pressure drop.

B. Giridhar
01 Mar 2008, 13:27

Pls define me the micron size w.r.to EU filter grade

umesh
09 Mar 2008, 06:22

Please let me know the acceptance criteria of hepa filter when dop test is carried out at the hepa filter media,bonding and gasket for the hepa filter with the effeciency of 99.997%.And pharma regulatory comments on this part.

umesh
09 Mar 2008, 06:23

please let me know the maximum velocity by which air pass through the hepa media for one square feet of area

C Karuppusamy
14 Apr 2008, 04:34

Please send EU standered for filter efficency alog with the comparison with other stansards.

please let me know the maximum velocity by which air can pass through the HEPA Filter.

Mr.yotsak
03 May 2008, 09:54

Request quotation for HEPA filter
Spec.
size ; 600mm*600mm*295mm(or 300)
Casing ; SUS304
Efficeincy ; >99.997% at 0.3 micron
Flow rate ; >4 Nm3/min
Seal ; general
Pre-filter
size 600mm*600mm*50mm
General spec in market

SHYAM
07 Jun 2008, 13:34

Pls define me the micron size w.r.to EU filter grade

Abhijit K
16 Jun 2008, 06:25

Sir,

I would like to know about EU filter ratings, their respective filtration efficiancy and the max allowable air velocity across the media. (I am not concern about filter bax face velocity) Kindly suggest.

Thanks n Regards,
AMK

Paul
16 Jun 2008, 07:27

A table of filtration values can be found here: http://www.filtration-engineering.co.uk/air_filter_testing.htm

syurya septiani
10 Jul 2008, 02:06

Request quotation for HEPA filter
Spec.
size ; 600mm*600mm*295mm(or 300)
Casing ; SUS304
Efficeincy ; >99.997% at 0.3 micron
Flow rate ; 2500 cfm
Seal ; general
Pre-filter
size 600mm*600mm*50mm
General spec in market

deven
14 Jul 2008, 01:11

I want the information related to HEPA filter efficency testing and DOP regulatory requirement

KANDANURU SUDHAKAR
25 Aug 2008, 06:17

Dear Sir,

I want the information related to HEPA filter efficency testing and DOP regulatory requirement

ketan valand
09 Sep 2008, 02:41

I requisted You pl. send EU standered for filter efficency

ritesh patel
16 Sep 2008, 07:48

i would like to know thw effective area of hepa filter or calculation method.

ritesh patel
16 Sep 2008, 07:50

i know the HEPA FILTER INTERGRITY TEST WITH DOP BUT ANY OTHER CHEMICAL IS THEIR?

anyarporn tansirikongkol
05 Oct 2008, 21:36

Dear sir,

I would like to know what is the general spec for Pre-filter and which Typical Euro Class it would fall in.

mauik
06 Oct 2008, 13:19

Great article, excellent info. I had no idea that the HEPA filters could actually filter things I can't even see!

I always get my <a href=”http://www.iaqsource.com”>Furnace Filters</a> from this site, they will email you a reminder when to change out your furnace filter, which I love because I am always forgetting to do it without!

KSV Ramachandra Rao
17 Oct 2008, 03:10

Can you please let me know about different rating of filters?

r sopko
22 Oct 2008, 14:23

What hepa filter rating do I need for a class 10,000 ISO -7 pharmacy clean room? 99.9%, 95%, 90-95% ?

santosh koli
28 Oct 2008, 23:06

Sir,

I would like to know about HEPA filter-about the 20 air current changes

B Giridhar
11 Nov 2008, 07:25

What guide line to be followed for Temperature maping of Ware house like area with different height levels.

How can we determine the number of sampling locations & any reference?

Any reference for seasons study of temperature variations w.r.to ambient?

Sindhu
11 Nov 2008, 07:32

Pls define me the micron size w.r.to EU filter grade

IS F8 class is 5 micron?

JOHAN
19 Dec 2008, 04:06

There are HEPA filters with ratings 11, 12 and 13. In what sense are they different?

Johan
19 Dec 2008, 04:10

What is the difference between HEPA filter ratings/types 11, 12 and 13?

anil
09 Jan 2009, 07:25

what is the difference between HEPA filters and pre filters

K.Rajan
17 Jan 2009, 03:20

Kindly mention EU filter grade and the corresponding micron size.

Árpád
02 Feb 2009, 00:40

Hello,
I could not information here what is the difference for example between HEPA12 and HEPA13 filters.

Music_Mp3_ideardemi
05 Feb 2009, 02:44

Hello to all :) I can’t understand how to add your site in my rss reader. Help me, please

Anand Mendhe
05 Feb 2009, 07:42

Please tell us about EU Standard used for HEPA FILTERS

Surendra
22 Feb 2009, 08:40

Wwhat is the Difference between EU 9 and EU 13 Filters.

P. S. Negi
12 Mar 2009, 01:06

Please send details about EU filters & there equivalent micron sizes. Application is HVAC

anoop rawat
24 Apr 2009, 03:00

I requisted You pl. send EU standered for filter efficency
requisted You pl. send EU standered for filter efficency alog with the comparison with other stansards
also let me know whether hepa can be of efficiency below .3 micron

vikram jaiswal
05 May 2009, 09:44

what is the difference between EU grades and H grades like EU 14 and H14 and what does EN1822 belongs.

thanks

karthik
14 May 2009, 01:38

Please send EU standered for filter efficency alog with the comparison with other standards.

please let me know the maximum velocity by which air can pass through the HEPA Filter.

Nagendra
23 May 2009, 00:02

Hi

i want eu standards each micron wise plz. give me that detail

bharat Makati
07 Jun 2009, 05:47

I whould like know how do I re use hepafilter

Nitish C Bhatt
02 Jul 2009, 07:32

I would like toknoe anout EU grade filters and their fitration % wrt particle size

Nirmala John
08 Aug 2009, 06:16

Dear Madam/ Sir,

I would like to know the EU grade filters. I have read that HEPA filters are off different types, I would like to know the pore size of HEPA filters with their grade. I want to Know all the classifications for the filters.

I would be really grateful if you can help me out.

Waiting for your reply.

With warm regards,
Nirmala. J. M.

nandlal punasya
09 Aug 2009, 10:16

how we check leakage in loop in AHU SYSTEM

dcvenkata Reddy
17 Aug 2009, 04:31

Pl let me know the name of bacteria after passing of 0.2 micron filter

NAYYER
02 Sep 2009, 04:58

HI.
plz tell me more about panel pre and hepa filter who is use for hospitals and labourtries.
thanks and kind regards,

nayyer bin abdul latif

pramod Manral
10 Sep 2009, 00:14

pl get me updated

b.kishore
21 Sep 2009, 03:44

dear sir,
please send the EU-STANDARED FILTER DETALS ,WHAT IS THE MATERIAL USEING OF THESE FILTERS,WHAT IS THE MICRON OF OTHER FILTER

KSV Ramachandra Rao
07 Oct 2009, 02:20

Can I have different rating of HEPA Filters?

Samson Sariola
15 Oct 2009, 02:17

Sir,

Just want to ask if what is the standard / average life span of HEPA filter rated at 99.99% @ 0.3 micron used in Class 10K cleanroom? Is there an ASHRAE standard for this?

Thanks,

Sammy

SHANXX
16 Oct 2009, 06:48

I whould like knowthe maximum velocity by which air can pass through the HEPA Filter,can i get hepa filter rating chart.

Amrendra kumar Singh
28 Oct 2009, 02:17

Please send EU standered for filter efficency alog with the comparison with other standards.

Hemendra
06 Nov 2009, 22:30

Please let me know the Hepa Filter average life span inrespect of air pressure, how much required of min. & max. air pressure for Hepa.

karshan
14 Nov 2009, 05:11

I have eu-13 hepq filter installaed and air change 25 .what class of air will available/ expect?

dr prashanth
25 Nov 2009, 04:56

-how to discard the used HEPA filters
-how do we see the efficacy of HEPA filters

Mukesh Singh
25 Nov 2009, 22:05

HEPA classification as per EU -

Filter class Efficiency of filter
EU-1 Synthetic media rod filters
EU-2 85% down to 20 micron
EU-3 90% down to 10 micron
EU-4 95 % down to 10 micron
EU-5 Down graed microvee 80 % down to 5 micron or synthetic media bag filter
EU-6 Microvee filter 99.9% down to 5 microns or synthetic media bag filter
EU-7 Fine filter 99 % down to 3 micron or fiber glass bag filter
EU-8 50 % down to 0.3 microns or fibre glass bag filter
EU-9 Filter glass bag filter 2 micron
EU-10 HEPA 95 % down to0.12 micron
EU-11 HEPA 99.97% down to0.12 micron
EU12 HEPA 99.99% down to0.3 micron
EU-13 Mini pleat 99.997% down to0.3 micron
EU-14 Mini pleat 99.999% down to0.3 micron
EU-15 Mini pleat 99.999% down to0.12 micron
EU-16 99.9999 %
EU-17 99.99999 %

KSV Ramachandra Rao
25 Nov 2009, 22:58

Can any one tell me about the classification of pre-filters used in pharma industry?

R.W. WAGH
10 Dec 2009, 05:58

For sterilizing tunnel maintained at 300 degC plus is there any effect on the efficiency of HEPA filter due to high temperature. Whether HEPA of H12 rating is adequate for Tunnel.

Rajkumar.S
02 Jan 2010, 07:08

sir,
kindly give me example for calculating pressure drop using Darcy's law

subbaraju
16 Jan 2010, 05:25

Let me know static pressure calculation

Dr. Farid Uddin Ahmed
18 Jan 2010, 20:38

Please let me know the difference between Hepa-13 and Hepa-14 grades of filters.

Mitesh
22 Jan 2010, 23:13

Dear sir / madam,

1] How to measure the pressure drop after the HEPA filter?

2] Can we use the HEPA filter after 2 years if it is working seitsfactory after 2 years. If yes, how can we justify the same?

Regards,

Mitesh Oza

M Ashraf Ali
01 Feb 2010, 04:14

I want to know the gradation of filter because in pharmaceutical industries people are used to indentify the filter by grade like H 12, H 13, EU 12
I am requesting you please inform me regarding this grade and If possible than send me this grade with micron size

A_Excel
04 Feb 2010, 00:31

Pressure drop can be measured by measuring the air velocity in front of the filter. Also, best measurement of usability can be given by DOP and Particle Count tests.

Nitin Kulkarni
22 Feb 2010, 00:26

Dear sir,

Updated procedure for validation of AHU.

Flow rating through Hepa filters.

NBK

Mahesh
27 Feb 2010, 05:04

Hi Sir,
I want to calculate velocity across the filter element (porous media) . I have pressure drop across the filter element at volume flow rate . Then which equation would be use to calculate velocity across the filter and boundry condition .

Mahesh
27 Feb 2010, 05:06

Plz suggest me for calculation of resistance across porous media.

Mahesh
27 Feb 2010, 05:10

Alkesh Gharat
06 Mar 2010, 09:53

Dear sir,
1]I requisted You pl. send EU standered for filter efficency alog with the comparison with other standards.
2]How much cfm can handle 1sq ft of hepa fliter ,if any other calculation plase send me.

Jasveer
09 Mar 2010, 03:32

Dear Sir,

Please send me hepa filter SU - 4, RU - 4 specification detail in efficiency/microns ASAP.

Thanks.

HEPA Filter Pro Your Resource for HEPA filters

Air Filter Ratings

How Big is a Micron?

Other Types of Air Filters

Comments