To improve the reliability and accuracy of chamber tests for measuring emissions of volatile organic compounds (VOCs) from interior building products, the National Institute of Standards and Technology (NIST) and Virginia Tech (VT) have created a prototype reference material by loading toluene into a polymethylpentene (PMP) film (Cox et al. 2010). The characteristic emission parameters of the reference material, including toluene concentration in pre-loaded films (C0), material-phase diffusion coefficient (D), and material/air partition coefficient (K), have been measured at 23 ºC and 0 % relative humidity (RH). A fundamental mass-transfer model is then used to predict the true toluene emission rate from the reference material at 23 ºC, which serves as the reference value for validating the results measured by different laboratories and evaluating test performance. The feasibility of the reference material and its usefulness has been demonstrated in several inter-laboratories studies (Howard-Reed et al. 2011). In the present work, the temperature and humidity dependence of the emission parameters are determined and the model is further validated for a range of temperature and humidity levels. The reference material can therefore be applied with confidence over a wider range of emission chamber testing conditions.
Conference Dates: July 8-12, 2012
Conference Location: Brisbane, -1
Conference Title: Healthy Buildings 2012 Conference
Pub Type: Conferences
VOCs emissions testing, VOCs emission model, standard source, temperature, humidity