VENTILATION, ENERGY AND INDOOR AIR QUALITY

As ventilation is a significant consumer of energy the rates of ventilation have often been minimised, particularly after the energy crisis in the early 70’s, in order to reduce equipment and energy costs. Buildings, particularly those in cold climates, have also become more airtight a factor which has reduced ventilation airflow through the building envelope. This has caused in many countries indoor air quality problems. It has been shown that ventilation rates have adverse effects on communicable respiratory illnesses; on sick building syndrome symptoms; on productivity and perceived air quality. In many studies, the prevalence of sick building syndrome symptoms has also been associated with the characteristics of ventilation systems. Often the prevalence of SBS symptoms is higher in air-conditioned buildings than in naturally ventilated buildings. The evidence suggests that improvements in the hygiene, commissioning, operation and maintenance of air handling systems may be particularly important for reducing the negative effects of air conditioning systems.