NAFA Guide to Air Filtration 5.ppt

HVAC

1. NAFA Guide To Air Filtration
Chapter 5
HEPA, ULPA and Super ULPA
Filters
presented by the
National Air Filtration Association
Fifth Edition

2. HEPA and ULPA Filters

3. HEPA Filter History
•The first HEPA was developed in the 1940’s
under a classified government project for
filtration of radioactive contaminants.
•They were required as part of the Manhattan
Project which developed the atomic bomb.
•The original filters were quite bulky and
inefficient as compared to current HEPA
filters. Some had asbestos fibers
•After WWII, HEPA filter technology was
declassified with commercial manufacturing
beginning in the 1950’s.

4. Approx. HEPA Filter
Applications in Industry
Electronics/Micro
31%
Process/Food/
Optical
24%
Pharm/Biotech/
18%
Aerospace/
Auto 6%
Medical/Hospital
Device
21%

5. High Efficiency Particulate
(HEPA) Air Filter
“Throwaway extended-medium dry-type filter in
rigid frame, when tested at rated airflow having
minimum particle-collection efficiency of 99.97%
for 0.3 micrometer (µm) mass median diameter
particles of DOP when tested in accordance with
MIL-STD-282 particles of thermally-generated
DOP particles or specified alternative aerosol.”

6. THEORETICAL HEPA FILTER COLLECTION EFFICIENCY
99.999
0.1 1.0 10.00.01
PARTICLE DIAMETER (MICRONS)
99.99
99.97
99
90
50
10
HEPA Filter Mechanisms

7. Components of a HEPA
Filter
•Media
•Separators
•Filter pack
•Sealant
•Framing (cell sides)
•Gasketing

8. Wet Laid Glass Fiber Media
HEPA Filter
microglass fibers
Engine Filter-
cellulose paper

9. Separator Styles
•Aluminum Separators
–Corrugation heights
from .06” to .20”
deep
•Mini-Pleat
–Coated String
–Embossed Media
–Ribbon of Media
–Adhesive Bead
Minipleat using string separators

10. Filter Sealants
•Rubber Based
•Urethane
•Epoxy
•Hot Melt
•Silicone

11. Frame Materials
•Particle Board
–Fire Retardant
–Standard
•Plywood
–Fire Retardant
–Standard
•Extruded Aluminum
•Formed Sheet Metal
–Stainless Steel
–Galvanized Steel
–Aluminum

12. Filter Performance
•Filter Performance measures penetration
(then converted to efficiency)
•Most Penetrating Particle Size (MPPS) for
differing flow rates
•Each filter is tested –(non-destructive
test)

13. Filter Performance&
Application
HEPA
•99.97% for 0.3 micron particles MMD (Type A)
•99.99% for 0.3 micron particles MMD (Type C)
ULPA
Minimum Particle Collection Efficiency
•99.999% 0.1-0.2 Micrometer Particles (Type F)
SUPER ULPA
•99.9999% on MPPS (Type G)
See page5.6-for all filter types

14. Gasketing
•Closed-cell Neoprene
Gasket
•Non-Newtonian Gel Seal

15. HEPA Filter Holding Devices

16. Terminal HEPA Filters
Room-side Replaceable Disposable Terminal
Modules Modules

17. Bag In / Bag Out
Housing

18. Proper Training
•Do Not Change Bag In/Bag Out Filters
Without Proper Hands-on Instruction,
Training, and Accreditation –NAFA
Certified Technician, Level II

19. HEPA Filter Are
•Most Always Second or Third Filter
Bank
•Pre-filtered with Pleat and or MERV
15/16 Filter
•Using Neoprene Gasket -Always In
Locking HEPA Filter Holding Frame
•Using Gel Seal –held in place
•Always Exact Size –Not Nominal
•Always Requires Special Handling,
Installation, and Testing

20. HEPA Filters
Because they catch everything, always
wear respirator protection when changing
any type of HEPA filter

21. Sample Questions
•In order to be classified a HEPA filter, the
efficiency must be at least?
99.97% on 0.3 micrometer particles
•ULPA stands for?
Ultra-Low Penetration Air filter
•Two types of gasketing for HEPA’s are?
Closed Cell Neoprene and Non-Newtonian
Gel Seal

22. Thank you.
•Other Questions?