Indoor Air Cartoon Journal, July 2019, Volume 2, #68

The liveable indoor environment experience will be difficult to achieve if occupants find it difficult to accept the quality of the air they are breathing. Even without the introduction of pollutants sources, the mere presence of human can compromise indoor air quality (IAQ).  The breakdown of proteins in the sweat secreted by bacteria, in the sweaty areas of the human body, to acidic substances causes the smell, referred to as bio-effluent. High indoor temperature and humidity conditions, occupancy density, and metabolic rates increase the secretion of sweat containing the proteins.

There is a global rise in the population of human in indoor environments – building, cars, trains, airplane. The need to save energy had lead many operators of these indoor environments to reduce ventilation rate and increase the indoor temperature. These occurrences cause more bio-effluent to be released in indoor environments.  The achievement of thermal condition that is comfortable for occupants will reduce bio-effluent. However, bio-effluent problem and its impact in compromising the perceived IAQ will still occur with lack or inadequate ventilation rate.  Poor ventilation rate increases carbon dioxide (CO2) and indoor air pollutants to concentrations that compromise the perceived IAQ.  In practice, high CO2 is an indication of lack of or inadequate ventilation rate.

Studies have shown that occupants will report acceptable perceived IAQ if the ventilation rate is adequate. Continuous efforts are need towards the adoption of adequate ventilation rates with minimal energy consumptions. The adoption of renewable sources of energy will reduce the energy consumption concerns associated with the use of ventilation. An economy that makes the adoption of the renewable sources of energy economical friendly will help a great deal in improving perceived IAQ.

Do you want to know more about this topic? Read Tsushima et al. (2018) and Zhang et al. (2017) papers.