Summary
Chapter 4 deals with the reasons for ventilating buildings, how ventilation rates are chosen for specific situations, and the how to determine and maintain good indoor air quality, IAQ.
Introduction
The maintenance of good indoor air quality (IAQ) is one of the major objectives of air-conditioning systems, because IAQ problems are a significant threat to health and productivity. The primary factors that influence and degrade IAQ are particles, gases, and vapors in the air.
Air Pollutants and Contaminants
Air pollutants and contaminants are unwanted airborne constituents that may reduce the acceptability of air. Some contaminants are brought into the conditioned space from outside, and some are generated within the space itself.
Indoor Air Quality Effects on Health and Comfort
Contaminants can be classified based on their effects: fatal in the short term, carcinogenic (cancer causing substances), health threatening, and annoying, with an impact on productivity and sense of well-being
Controlling Indoor Air Quality
Maintaining acceptable IAQ depends on the judicious use of three methods: source control, filtration, and dilution. This section also included a more detailed discussion on source control, and on filtration.
ASHRAE Standard 62 Ventilation for Acceptable Indoor Air Quality ANSI/ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality1 was published in 1971, 1981 and again fully revised in 1989. The complete revisions made it easy to reference in Building Codes. In many jurisdictions, earlier versions of the standard will remain the legal requirement for many years Since 1997, to align with the ANSI “continuous maintenance” process, the Standard is updated a bit at a time and is not required to be a consistent, whole document. Standard 62.1-2004 applies to “all indoor or enclosed spaces that people may occupy” with the provision that additional requirements may be necessary for laboratory, industrial, and other spaces.
We introduced the idea of the ventilation rate procedure, and the formula
Bibliography
1. ASHRAE/ANSI Standard 62.1-2004 Ventilation For Acceptable Indoor Air Quality
2. ASHRAE/ANSI Standard 62.2-2004 Ventilation and Acceptable Indoor Air Quality in Low Rise Residential Buildings
3. Industrial Ventilation published by the American Conference of Governmental Industrial Hygienists 23rd edition 1998
4. ASHRAE Standard 52.1-1992 Gravimetric and Dust Spot Procedures for Testing Air Cleaning Devices used in General Ventilation for Removing Particulate Matter
5. ASHRAE 52.2-1999 Method for Testing General Ventilation Air-Cleaning Devices for the Removal Efficiency by Particle Size