Air quality as an important indicator for ergonomic offices and school premises

A. Traumann¹, M. Kritsevskaja², P. Tint¹,* and D. Klauson²

¹Department of Work Environment and Safety, Tallinn University of Technology, Ehitajate 5, EE19086 Tallinn, Estonia; *Correspondence: piia.tint@ttu.ee 2Department of Chemical Engineering of Tallinn University of Technology, Ehitajate 5, 19086 Tallinn, Estonia

Abstract:

The health risk assessment model for office rooms contains the physical indoor air factors and the risks connected with the use of computers. Four comfort classes have been postulated. Indoor air quality is the main risk factor at workplaces such as office rooms and schools besides non-ergonomic use of computers. High levels of carbon dioxide (CO2) could be observed due to poor ventilation systems and inadequate air exchange due to inoperable windows. Overcrowded classrooms could also be the reason for a high CO2 level. Lowering the occupancy and increasing the breaks between classes could alleviate the high CO2 concentrations in schools and offices. The data of Estonian investigators are analyzed. Experiments for determination of the adequacy of ventilation rate and the respective build-up of CO2 are carried out by the authors of the paper.

Key words:

carbon dioxide, ergonomic workplace, indoor air-, offices., schools

Exploring the effect of carbon dioxide demand controlled ventilation system on air humidity

M. Reinvee*, J. Uiga, T. Tärgla, P. Pikk and A. Annuk

Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56,EE51014 Tartu, Estonia; *Correspondence: mart.reinvee@emu.ee

Abstract:

Earlier studies have indicated that elevated or inadequate levels of carbon dioxide(CO2) in indoor air impairs users in the performance of decision-making. For this reason andalso for potential energy consumption reduction carbon dioxide based regulated demandcontrolled ventilation (DCV) systems are used. Although DCV systems use less electricalenergy than conventional ventilation systems, there is a problem in colder climates with thelowered humidity of air. It has been discovered in earlier studies that even brief exposure torelatively dry air has an impact on voice control parameters. In the current article, the humiditygains from ordinary usage of a faculty building, where a DCV system and room basedtemperature control is utilised, are examined. For that, the changes in the specific indoorhumidity were compared to the changes in the specific ambient humidity.

Key words: