CO2 and Ventilation

1
CO2 and Ventilation

• Altered ventilation rates ? energy savings
• air taken into building must be conditioned (uses
  energy)
• But, reduced ventilation rates ? contaminants
• CO2 level is one indicator of indoor air quality
• Common Levels of CO2
• 350-450 ppm fresh air
• 2500-5000 ppm can cause headaches
• 100,000 ppm 10 people pass out in lt 10 min

2
Ventilation Standards

• Minimum Ventilation Rates
• Minimum 15 cf/mperson
• Hospital 30 cf/mperson
• Smoking Lounge 60 cf/mperson
• CO2 is one indicator of the indoor ventilation
  rates.
• ASHRAE standard requires building levels to be
  between 350 450 ppm (outdoor air) and 1,000 ppm

Determined by American Society of Heating
Refrigeration and Air-Conditioning Engineers
(ASHRAE)
3
Making CO2 measurements

• Instrumentation
• Telaire CO2 Meter
• Dual Beam infrared absorption
• LED puts out radiation
• Reference channel of standard gas
• Makes comparison with other beam
• HOBO Units Data Logging (2x external)
• Can measure temperature, relative humidity, two
  other inputs (such as values from Telare Meter).

4
Ventilation Initial ideas 1

• Thermal recovery system
• Transfer energy from the exhausted air to
  incoming air for energy savings (works for both
  hot air in winter and cold air in summer)
• Involves
• Research into thermal recovery systems
• Look at system that is present in Mallinckrodt
• Cost analysis of system vs. energy savings

5
Ventilation Initial ideas - 2

• Adaptive exhaust system
• maintain the desired level of O2 / CO2 while
  taking into account building use
  (weekends/weekdays, days/nights)
• Involves
• Understanding how the exhaust/recirculation
  system in William James Hall works
• Research into exhaust system/control device