title: Influence of humidity on the initial emittable concentration of formaldehyde and hexaldehyde in building materials: experimental observation and correlation.
abstract: Humidity is one of the main environmental factors affecting the emission rate and key parameters of formaldehyde and volatile organic compounds (VOCs) from building materials. Meanwhile, the initial emittable concentration (Cm,0) is proved to be the most sensitive key parameter to the emission behaviours. However, there is no report on the relationship between humidity and Cm,0. In this paper, Cm,0 of formaldehyde and hexaldehyde from a type of medium density fiberboard in absolute humidity (AH) range of 4.6-19.6 g/m(3) at 25 °C were tested by virtue of a C-history method. Experimental results indicate that Cm,0 is dramatically dependent on AH, increased by 10 and 2 times for formaldehyde and hexaldehyde when AH rising from 4.6 g/m(3) to 19.6 g/m(3). A linear relationship between the logarithm of Cm,0 and AH is obtained based on the measured results. In addition, a correlation characterizing the association of emission rate and AH is derived. The effectiveness of the correlation is verified with our experimental results as well as data from literature. With the correlations, the Cm,0 or emission rate different from the test AH conditions can be conveniently obtained. This study should be useful for predicting the emission characteristics of humidity changing scenarios and for source control.
authors.affiliation: Department of Building Science, Tsinghua University, Beijing 100084, China.|Beijing Key Lab of Indoor Air Quality Evaluation and Control, Beijing 100084, China.
authors.forename: Shaodan
authors.initials: S
authors.lastname: Huang
authors.affiliation: School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China.
authors.forename: Jianyin
authors.initials: J
authors.lastname: Xiong
authors.affiliation: Department of Building Science, Tsinghua University, Beijing 100084, China.|Beijing Key Lab of Indoor Air Quality Evaluation and Control, Beijing 100084, China.
authors.forename: Chaorui
authors.initials: C
authors.lastname: Cai
authors.affiliation: China Academy of Building Research, Beijing 100013, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Building Science, Tsinghua University, Beijing 100084, China.|Beijing Key Lab of Indoor Air Quality Evaluation and Control, Beijing 100084, China.
authors.forename: Yinping
authors.initials: Y
authors.lastname: Zhang