1. PARTICULATE MATTER REMOVAL THROUGH THE USE OF VENTILATION SYSTEM, A CASE STUDY IN UNIVERSITY CLASSROOMS
Wannawit TAEMTHONG, Watchara SIRIKULYANONA
King Mongkut's University of Technology North Bangkok, Bangkok, Thailand,

2. Problem Statement
The particles could come from combustion engines, combustion for energy production, construction activities, industrial activities, friction between tires and pavement, and from braking system of cars on the road.
Small particles are inhalable and can penetrate the thoracic region of the respiratory system.
Health effects due to exposure to such small particles in short and long terms are aggravation of asthma, respiratory symptoms, and cardiovascular and respiratory diseases.
WORLD HEALTH ORGANIZATION (WHO), Health effects of particulate matter, 2013.

3. Problem Statement
Public health awareness on indoor air pollution has lagged behind outdoor air pollution [2].
Several studies reviewed by Polednik [3] shown that particle concentration levels in school facilities may have a significant impact on students’ health and performance.

4. Problem Statement
An exposure to particle matter in the 10 micron size could 0.6% increase in the weekly rate of emergency room visits for upper respiratory infections for every 10 µg/m3 [4].
Classroom ventilation can create indoor environmental conditions that could reduce risk of health problems, minimize discomfort, and eliminate negative effects on learning [5].

5. Objective
An objective of this research is to determine a ventilation system that can remove PM2.5 from classrooms effectively in order to improve indoor air quality.

6. Experimental Room A lecture room of 35 square meter area was selected.
It is located at 6th floor of Building 88 at the King Mongkut’s University of Technology North Bangkok.

7. Experimental Room

8. Experimental Room

9. Ventilation Fan
A fresh air supply fan has a capacity of 181 cfm. or 308 m3/hr (total).
Exhaust fan has a capacity of 141 cfm. or 240 m3/hr (each).
Exhaust fan
Fresh air supply fan

10. Filters in Ventilation Fan
The pre-filter is a class G3 or equivalence to MERV5. It has less than 20% of filter efficiency.
The medium filter is a F8 class or equivalence to MERV It has filter efficiency about 90-95%.
The HEPA filter is U13-U15 class, and has filter efficiency about %.

11. Fresh Air only

12. Fresh Air with Top Exhaust

13. Fresh Air with Bottom Exhaust

14. Fresh Air with Top and Bottom Exhaust

15. Results: Fresh Air only
FA system can reduce PM2.5 for 22%.

16. Results: Fresh Air with Top Exhaust
FA/TE system can reduce PM2.5 for 22%.

17. Results: Fresh Air with Bottom Exhaust
FA/BE system can reduce PM2.5 for 33%.

18. Results: Fresh Air with Top and Bottom Exhaust
FA/TE/BE system can reduce PM2.5 for 50%.

19. Energy consumption before and after turning the ventilation on

20. Average concentration of PM2
Average concentration of PM2.5 particles in µg/m3 before and after turning the ventilation on
Ventilation System FA
FA/TE
FA/BE
FA/TE/BE
Averaged PM2.5 Before Turn the Ventilation on (17 min.) 18 20 24 26
Averaged PM2.5 After Turn the Ventilation on (30 min.) 14 15 16 13
% Reduction in PM2.5
22%
25%
33%
50%
Reduction Rate in µg/m3 per minute
0.133
0.167
0.267
0.433

21. Additional energy consumptions for all experiments due to ventilation systems
Using the fresh air supply alone can reduce the PM2.5 well enough comparing to other ventilation systems when energy consumptions is considered.
The fresh air supply system can reduce PM2.5 for 22%, and consume additional energy for 8%, which is the highest efficiency in the experiments.

22. Conclusions
In term of energy consumption, this research would recommend designing a public room such as a classroom with a fresh air supply system with no exhaust in order to reducing dust particles in the air.
The fan should provide a minimum ventilation rate at 15 cfm/person. However, these results could be differently if experiments were done in Winter where cold air are outside and heater is operated.
Bottom exhaust should be avoided in Summer, since it drains cool air out faster resulting in more energy consumption.