Early-stage concentrations of formaldehydes and TVOCs in a new low-energy building

Abstract

This paper deals with temporary discomfort caused by characteristic odours from new objects and materials in office buildings. Earlier investigations have shown that increased ventilation rates in residential buildings decrease the indoor concentrations of non-occupant-related indoor air pollutants such as aldehydes and total volatile organic compounds (TVOCs). To study how this basic principle for the control of indoor air pollutants complies with a demand-controlled ventilation, which is an important energy efficiency measure in modern office buildings, the authors have designed and conducted a serial of field tests. Concentrations of aldehydes and TVOCs have been measured in two newly built and identical meeting rooms under different ventilation strategies. By overruling the existing demand control ventilation and increasing gradually but differently the air change rates in the rooms over a course of five weeks, the concentration of formaldehyde and TVOCs decreased for about 75 % from the initial values of ca. 45 μg/m3 and ca. 400 μg/m3 respectively. Impact of door openings on instantaneous indoor air quality has been studied in parallel by combining CO2 measurements and numerical simulations. Good agreement was found between the simulated and measured CO2 concentrations and thereby the door opening model was verified.