Paper 8: Volume 5 No.2 Sept 2006 Edition
Air Quality
Inside a
School
Building
: Air Exchange Monitoring, Evolution of Carbon Dioxide and Assessment of
Ventilation Strategies
E.
Z. E. Conceição1 and M. M. J. R. Lúcio2
1FCMA,
University
of
Algarve
, Gambelas Campus, 8005-139
Faro
,
Portugal
2Regional Directory of Education of Algarve, Sítio das
Figuras, EN 125, 8000-761
Faro
,
Portugal
Buy
paper for email delivery
Credit Card or PayPal
Abstract
This paper presents an
assessment of indoor air quality and various ventilation strategies inside
a school building located in the south of
Portugal
. In the first phase, ventilation rate was experimentally evaluated using
the tracer gas method. In the second part, different airflow typologies
were investigated and, after calculating the air exchange and flow rates
for each of them, the evolution of metabolic carbon dioxide inside the
spaces was numerically estimated.
Ventilation measurements
were made in classrooms, auditorium, offices, staff and computer rooms.
The assessment of ventilation was based on evaluating the carbon dioxide
produced by the occupants for three ventilation approaches; these were:
one based on cross-flow natural ventilation (in current use) and two based
on forced ventilation systems. In the case of the forced systems, one was
based on providing a constant flow to meet the required Portuguese
ventilation standard in the main occupied rooms while the other was an
adjusted constant rate based on a simple calculation procedure that took
into consideration the air quality needs of all the spaces including
corridors and atria. This approach was developed to produce an efficient
yet inexpensive ventilation approach that did not incorporate expensive
sensors and control systems.
Carbon dioxide evolution
predictions were made using software that evaluated the thermal response
and the air quality of a building with complex topology. The numerical
model used to evaluate air quality, was based on mass conservation
integral equations in which the final equations system was solved through
the Runge-Kutta-Fehlberg method with error control.
A statistical study of the occupation cycle in the school building
during the day was developed.
Key words: indoor air
quality, schools, tracer gas measurements, carbon dioxide evolution, air
exchange rate, airflow rate, ventilation systems, age of air, ventilation
efficiency, occupancy schedule.
References
ACGIH: (1999), “TLVs and
BEIs”, American Conference of Governmental Industrial Hygienists,
Cincinnati
.
ANSI/ASHRAE Standard 62.1: (2004) “ASHRAE Standard – Ventilation for
Acceptable Indoor Air Quality”, American Society of Heating,
Refrigerating and Air-Conditioning Engineers, Inc.,
Atlanta
.
Bayer CWB, Crow SA and
Fischer J: (2000), “Causes of indoor air quality problems in schools”,
Energy Division Oak Ridge National Laboratory, U. S. Department of Energy,
U. S. A.
Breum NO: (1988), “The
Air Exchange Efficiency of a Lecture Hall”, Proceedings of Second
International Symposium on Ventilation for Contaminant Control,
London
,
England
, pp373-380.
Chaloulakou A and Mavroidis I: (2002), “Comparison of Indoor and
Outdoor Concentrations of CO at a Public School. Evaluation of an Indoor
Air Quality Model”, Atmospheric Environment, 36,
pp1769-1781.
Conceição EZE: (2003), “Numerical Simulation of
Buildings Thermal Behaviour and Human Thermal Comfort Multi-Node
Models”, Building Simulation 2003,
Eindhoven
,
Netherlands
, 1, pp227-234.
Conceição EZE, Silva AIN
and Lúcio MMJR: (2004), “Numerical Study of Thermal Response of School
Buildings in Winter Conditions”, RoomVent 2004,
Coimbra
,
Portugal
.
CR 1752:
(1998), “Ventilation for Buildings Design Criteria for the Indoor
Environment”, CEN (Comité Européen de Normalisation),
Brussels
.
Decreto-Lei nº 79: (2006), “Regulamento dos
Sistemas Energéticos de Climatização em Edifícios
(RSECE)”, Diário da República, I Série- A,
Nr 67, April 4th.
EUR 14449 EN: (1992), “Guidelines for
Ventilation Requirements in Buildings, Report No.11, European Concerted
Action – Indoor Air Quality & Its Impact on Man”, Commission of
the European Communities, Directorate General for Science, Research and
Development, Joint Research Centre – Environment Institute.
Fanger
PO
: (1988), “Introduction of the Olf and the Decipol Units to Quantify Air
Pollution Perceived by Humans Indoors and Outdoors”, Energy and
Buildings, 12, pp1-6.
Grieve PW: (1991),
“Measuring Ventilation Using Tracer-Gases”, Brüel & Kjaer,
Technical Review,
Naerum
,
Denmark
, February.
Heinsohn RJ: (1989),
“Macro-Modeling Using Sequential Box Models, ASHRAE 1989, Building
Systems, Room Air and Air Contaminant Distribution, pp. 200-205.
Howell RH and Land DW: (2004), “Air-cooled HVAC Retrofit: Safe
Bet for Vegas Schools”, ASHRAE Journal, Special Theme Issue –
School HVAC, pp28-34.
Kolokotroni M,
Ge
YT
and Katsoulas D: (2002), “Monitoring and Modelling Indoor Air Quality and
Ventilation in Classrooms within a Purpose-Designed Naturally Ventilated
School”, Indoor Built Environment, 11, pp316-326.
Lazzerini R, Curtis
D, Bowen R, Patel M, Ruscisa G; Lazzerini P, Renzio M, Zabot S,
Guarino D and Cellie A: (1991a), “ANNEX XV - Energy Efficiency in
Schools. Part one”. IEA - International Energy Agency.
Lazzerini R, Curtis
D, Bowen R, Patel M, Ruscisa G; Lazzerini P, Renzio M, Zabot S,
Guarino D and Cellie A: (1991b), “ANNEX XV - Energy Efficiency in
Schools. Part two”. IEA - International Energy Agency.
Lee SC and Chang M: (2000), “Indoor and Outdoor Air Quality
Investigation at Schools in
Hong Kong
”, Chemosphere, 41, pp109-113.
Levine KB; Sterling EM and
Collett CW: (1993), “Estimation of Outdoor Air Ventilation Rates Using
CO2 Concentrations”, ASHRAE Transactions, Part 1,
pp1554-1559.
Niemelä R, Saamanen A and
Koskela H: (1989), “A Comparison Between the Step-Up, Step-Down and
Pulse Injection Technique for the Measurements of the Mean Age of Air”, 10th
AIVC Conference,
Dipoli
,
Finland
, 25-28 September, pp17-30.
Olesen BW: (1997),
“International Development of Standards for Ventilation of Buildings”,
ASHRAE Journal, April, pp31-39.
Roulet
CA
: (1991), “Use of Tracer Gases to Assess Indoor Air Quality”, ASHRAE
Symposium on Indoor Air Quality and Energy Consumption,
Montreal
, September.
Roulet
CA
and Cretton P: (1992), “Field Comparison of Age of Air Measurement
Techniques”, ROOMVENT 92, Air Distribution in Rooms, Third
International Conference,
Aalborg
,
Denmark
, 3, pp213-229.
Sandberg M: (1981),
“What is Ventilation Efficiency?”, Building and Environment, 16,
(2), pp123-135.
Sandberg M and Sjöberg M:
(1983), “The Use of Moments for Assessing Air Quality in Ventilated
Rooms”, Building and Environment, 18, (4), pp181-197.
Scheff PA, Paulius VK, Huang SW, Conroy LM: (2000), “Indoor Air
Quality in a Middle School, Part I: Use of CO2 as a Tracer for
Effective Ventilation”, Applied Occupational and Environmental
Hygiene, 15, (11), pp. 824-834.
Warden D: (2004), “Dual Fan, Dual Duct Goes to School”, ASHRAE
Journal, Special Theme Issue – School HVAC, pp18-27.
World Health Organization – Regional Office for Europe: (2000), “Air
Quality Guidelines for Europe”, WHO Regional Publications, European
Series, No.91, Second Edition,
Copenhagen
.
|
