Ventilation in Modern Buildings

Ventilation in a building refers to the exchange of indoor and outdoor air, which is vital in maintaining a healthy IAQ. Insulated and airtight buildings with no proper ventilation confines harmful pollutants indoors. Also, high humidity build-up in indoor air can damage a building structure.  Additionally, elevated levels of humidity can make cooling equipment work harder leading to costlier energy bills.

Ventilating a building is a process that involves techniques that can introduce fresh and filtered air from the outdoors, also driving out stale air, combustion gases and high humidity from the indoors. Traditional ventilation or purpose-built openings in a building includes doors, windows, solar chimneys, wind towers, and trickle ventilators. These were the most common ventilation method of allowing fresh outdoor air to replace the indoor air, and still is prevalent in most traditional buildings. However, they are becoming highly inadequate as the air movement in these methods cannot be controlled in energy efficient buildings and also with increasing level of air pollution, outdoor contaminants cannot be prevented from coming in.

Sick Building Syndrome

Contaminated indoors are potential breeding zones for sickness and diseases that adversely affects the wellbeing of the occupants in a building. Sick building syndrome (SBS) is about a situation in which the occupants of a building with high contaminants experiences acute health – or comfort-related negative effects that seem to be linked directly to the time spent in the building.  The symptoms tend to increase in severity with the time people spend in the building, and improve over time or even disappear when people are away from the building.

The WHO has classified the symptoms of SBS into broad categories, that includes: mucous membrane irritation (eye, nose, and throat irritation), neurotoxic effects (headaches, fatigue, and irritability), asthma and asthma-like symptoms (chest tightness and wheezing), skin dryness and irritation, gastrointestinal complaints and more. SBS can reduces work efficiency and increases absenteeism in workers at workplaces. A general feeling of tiredness is often the most prevalent symptom in SBS.