RISK ASSESSMENT FOR AIRBORNE INFECTIOUS DISEASES BETWEEN NATURAL VENTILATION AND A SPLIT-SYSTEM AIR CONDITIONER IN A UNIVERSITY CLASSROOM
Marcelo Luiz Pereira1; Rogério Vilain1; Arlindo Tribess2; Lidia Morawska3
1 Federal Institute of Education, Science and Technology of Santa Catarina; 2 Universidade de São Paulo; 3 Queensland University of Technology
doi:10.20906/CPS/COB-2015-0358
Resumo
Air in most indoor environments contains a variety of particles and gaseous contaminants. These contaminants are commonly referred to as indoor pollutants when they affect human health and performance. The present study compares the risk of airborne infection between Natural Ventilation (opening windows and doors) and a Split System Air Conditioner in a university classroom. The Wells-Riley model to predict the risk of indoor airborne transmission of infectious diseases such as influenza, measles and tuberculosis was used. For each case, the air exchange rate was measured using a CO2 tracer gas technique. We found that opening windows and doors provided an air exchange rate of 2,3 air changes/hour (ACH), while with the Split System was 0,6 ACH. The risk of airborne infection ranged between 4,24 to 30,86 % when using the Natural Ventilation and between 8,99 to 43,19% when using the Split System. The difference of airborne infection risk between the Split System and the Natural Ventilation ranged from 47 to 56%. Opening windows and doors maximizes Natural Ventilation so that the risk of airborne contagion is much lower than with Split System.
Palavras-chave: Risk of airborne infection; Ventilation natural; Split system; Air changes/hour