Ventilation Standards

1. VENTILATION STANDARDS

2. EARLY STANDARDS
 1745 BCE: Code of Hammurabi
 Not specific about ventilation
 Traditional Practices
 Egyptians, Minoans, etc.
 1631: King Charles of England
 Windows must be taller than they are wide
 10’ (3m) Minimum ceiling heights

3. 19th CENTURY SCIENCE
 1836: Tredgold; 4 cfm/p (2 l/s/p)
 Used Reid; for House of Commons
 Odor based
 Rising recommendations from there
 1895: ASHVE; 30 cfm/p (15 l/s/p)
 F. Nightingale; M. Pettenkofer; J. Billings
 Contagion Based

4. 20th CENTURY INDUSTRY
 30 cfm/p (15 l/s/p) through 1925
 22 state codes adopted ASHVE guide
 1927 UBC: 1/8 window area instead
 Natural vs. mechanical controversy
 1946 ASA “Standard”: 10 cfm/p ( 5 l/s/p)
 Based on Yaglou revision to guide
 Odor vs. health controversy

5. ASHRAE STANDARD 62
 62-73 codified guide & ASA
 62-81 split based on smoking
 5 cfm non-smoking; 20 cfm smoking
 Oil prices & smoking enter picture
 Tobacco Industry Intervention
 62-89 Compromise
 15+ cfm/p (7.5+ l/s/p) moderate smoking
 0.35 ACH for residential

6. 62 RETRENCHES IN THE 90s
 Acceptance of smoking declines
 “moderate smoking” disappears
 Recognizes CO2 as surrogate for people
 Splits off low-rise residential
 62.2-2003 first residential standard
 Health vs. comfort controversy continues
 Other rates not changing much

7. 21st CENTURY 62
 ASHRAE reaffirms health objectives
 Reduces controversy
 Regular publication of 62.1 and 62.2
 Every 3 years from 2004 (2013 currently)
 International bodies following lead
 CEN (13779) and ISO developing standards

8. SEGUE INTO CO2 AND YOU
 Lavoisier finds CO2 and thinks it “bad air”
 We now know odors are a mixture
 CO2 is part of human bioeffluents
 CO2 can be used as indicator
 Combustion also generates it
 When is it a pollutant?

9. CO2 COCENTRATIONS
 30,000ppm: Short-term hazard
 5,000ppm: Typical occupational limit
 2,500ppm: Potential performance hit
 1,000ppm: Typical Standard 62 level
 400ppm: Typical background level

10. Demand Controlled Ventilation
 CO2 is NOT a contaminant of concern
 CO2 IS a way of controlling ventilation for
variable occupancy
 DCV allows operation at lower total
ventilation rates than that if not done
 Saves energy
 Complicated implementation

11. STATUS OF STANDARDS
 Both 62 evolving to meet needs
 62.2 beginning to look at contaminants
 Europeans and ISO improving
 ASHRAE leads IEQ-GA
 Thinking about health basis
 Thinking about real-time control

12. FUTURE
 Ventilation becomes
a component in
performance standard
 Health
 Comfort
 Sustainability