1 / 22

NAFA Guide To Air Filtration

NAFA Guide To Air Filtration. Chapter 1 Importance of Air Filtration presented by the National Air Filtration Association 2008. Fourth Edition. The Importance of Air Filtration.

bettycooper
Download Presentation

NAFA Guide To Air Filtration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NAFA Guide To Air Filtration Chapter 1 Importance of Air Filtration presented by the National Air Filtration Association 2008 Fourth Edition

  2. The Importance of Air Filtration. Air filtration supplies the means to obtain the level of particulate cleanliness required by any definition of “air conditioning.” An air filter (air cleaner) is a device used for the removal of particulate or gaseous (molecular) impurities from the air.

  3. Comfort Air Conditioning • Is described as the process of treating air to control simultaneously its temperature, humidity, cleanliness, and distribution to meet the requirements of the occupants of the conditioned space.

  4. Air We Breathe

  5. Aerosol - Gas • Regardless of its source, an airborne contaminant can be either an aerosol or a gas. • An aerosol is a suspension of solid or liquid particles in the air.

  6. Measurement of Contaminantsis in Micrometers aka Microns

  7. 1 MICROMETER A Micrometer (µm) is 1 millionth of a meter or in I/P - 1/25,400 of an inch Pollen 10 to 100 micrometers Salt is 40 to 200 micrometers

  8. Aerosols You’ve probably been asked by your friends, “Will I have to dust less if I buy one of your higher efficiency filters?

  9. Particle Size (µm) 100.0 50.0 10.0 5.0 1.0 .05 0.1 <0.1 Settling Velocity 59.2 feet per minute 14.8 feet per minute 7.1 inches per minute 2.5 inches per minute 5.1 inches per hour 1.4 inches per day 1.13 inches per day negligible-behave like gases Particle Settling Velocities

  10. Aerosols • Fumes are solid aerosols formed by the condensation of vapors of solid materials. • Fogs are liquid aerosols formed by the condensation of water vapor in the air. • Mists are liquid aerosols formed by the atomization of liquids. • Smokes are solid or liquid aerosols formed by the incomplete combustion of organic substances.

  11. Gases • A gas is any material that has the tendency to expand indefinitely and which completely and uniformly fills the container it occupies. • Vapors are gases formed by evaporation of materials that are normally liquid or solid.

  12. Measuring Particle Contamination • Measured by Weight – drawing air onto a pre-weighed paper target • Counting & Sizing – either through a membrane filter (old) or using an optical particle counter (OPC). See Chart on page 1.4 – NAFA Guide

  13. Size Distribution of Atmospheric Dust Sample Source: NAFA Guide to Air Filtration Percent by Particle Count Percent by Weight 30 micron 10 micron 0.005% 28% 5.0 micron 0.175% 52% 11% 3.0 micron 0.25% 6% 1.0 micron 1.07% <1.0 micron 3% 98.5%

  14. The Importance of Air Filtration. Air filtration supplies the means to obtain the level of particulate cleanliness required by any definition of “air conditioning.”

  15. Air Filters are used for a variety of purposes: • Protecting the health and well-being of the occupants of the space by removal of airborne microorganisms and particles. • Protecting the décor of occupied spaces by removing the staining portion of airborne dust. • Reducing maintenance of building interiors by reducing the frequency of washing such items as Venetian blinds and fluorescent bulbs.

  16. Protecting the contents of occupied spaces including paintings, tapestries, and other items of historic or cultural value. • Elimination of fire hazards by removing lint and other materials which might accumulate in the ductwork. • Removing airborne bacteria from operating room air to help prevent postoperative infection.

  17. Filter Efficiency • Properly evaluate the size of the particulate you want to remove. And at what efficiency. • Details on filter testing will be given in the presentation on Chapter 7. • ANSI/ASHRAE 52.2 Method of Test

  18. Draw-through System Detail Filter1 Filter 2

  19. Blow-through System Possible Terminal Filter

  20. Some Sample Questions 1 Millionth of a Meter is called a __________? Micrometer or Micron The air we breathe is composed mainly of __________? Nitrogen

  21. Sample Questions The size of particles in outdoor air are mainly ???% and smaller? 1 Micrometer and smaller _____(size) particles behave like a gas, have negligible settling rates and are affected by Brownian Motion. Particles less than 0.1 micrometers

  22. Thank you. Other Questions?

More Related