1. Indoor Air Quality
Secondary 1-3

2. Why is indoor air quality important?
Look at the pictures below and discuss with your group members: How would you feel if you were in the conditions below? Why?
Bedroom with windows closed
Crowded hall
Working place with an air conditioning system, working copier and smoke

3. Why is indoor air quality important?
We spend more than 70% of our time at home, and in offices and other indoor environments.
Poor indoor air quality can lead to discomfort, illnesses (e.g. headaches, itchy eyes, respiratory difficulties, skin irritation, nausea and fatigue), as well as absenteeism and lower productivity in the workplace.
Children, the elderly and those with existing respiratory or heart disease are more susceptible to the effects of poor indoor air quality.
Good indoor air quality safeguards the health of buildings’ occupants.

4. Common indoor air pollutants
Watch the video, match pollutants to their sources and solutions to the problems.
Teaching Resources on Indoor Air Quality for Primary and Secondary Schools

5. Unit of CO2 (PPMV) VS Percentage (%):
PPMV means “parts per million by volume”, 10-6.
In the atmosphere, normally CO2 ≈ 390 PPMV.
Then calculate % of CO2 in the air。
(Answer: CO2 ≈ 390 PPMV≈ % in the air)

6. Worksheet
C = Co + G/V
where:
C = concentration of a pollutant in the house (μg/m3)
Co = background concentration of that pollutant in the ventilation air (μg/m3)
G = generation rate of the pollutant inside the house (μg/min)
V = ventilation air flow rate (m3/min)
If Co = 20 μg/m3, G = 10 μg/min, V = 0.1, 0.5, 1, 2, 5 m3/min, Please calculate C and plot the curve:

7. Answer to the Worksheet
V(m3/min)
0.1
0.5 1 2 5
C(μg/m3)
120 40 30 25 22
V (m3/min)