Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (single variable).

<p>Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (single variable).</p

Measurement data and model prediction of formaldehyde concentrations in a ventilated chamber.

<p>Measurement data and model prediction of formaldehyde concentrations in a ventilated chamber.</p

Parameters for temperature influence study.

<p>Parameters for temperature influence study.</p

Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (multi variables).

<p>Influence of the measurement errors in <i>D</i>, <i>K</i>, and <i>C</i>₀ on the model prediction errors in <i>C</i>_a (multi variables).</p

Parameters of the chamber and the building material.

<p>Parameters of the chamber and the building material.</p

Parameters of the reference living room and the furniture.

<p>Parameters of the reference living room and the furniture.</p

Inter-laboratory studies for measuring VOC/formaldehyde concentrations in chamber air.

<p>Inter-laboratory studies for measuring VOC/formaldehyde concentrations in chamber air.</p

Temperature influence on model prediction of emissions.

<p>Temperature influence on model prediction of emissions.</p

Association between the Emission Rate and Temperature for Chemical Pollutants in Building Materials: General Correlation and Understanding

The emission rate is considered to be a good indicator of the emission characteristics of formaldehyde and volatile organic compounds (VOCs) from building materials. In contrast to the traditional approach that focused on an experimental study, this paper uses a theoretical approach to derive a new correlation to characterize the relationship between the emission rate and temperature for formaldehyde emission. This correlation shows that the logarithm of the emission rate by a power of 0.25 of the temperature is linearly related to the reciprocal of the temperature. Experimental data from the literature were used to validate the derived correlation. The good agreement between the correlation and experimental results demonstrates its reliability and effectiveness. Using the derived correlation, the emission rate at temperatures other than the test condition can be obtained, greatly facilitating engineering applications. Further analysis indicates that the temperature-related emission rate of other scenarios, i.e., the standard emission reference and semi-volatile organic compounds (SVOCs), also conforms to the same correlation as that of formaldehyde. The molecular dynamics theory is introduced to preliminarily understand this phenomenon. Our new correlation should prove useful for estimating the emission characteristics of chemicals from materials that are subject to changes in temperature

Standard Formaldehyde Source for Chamber Testing of Material Emissions: Model Development, Experimental Evaluation, and Impacts of Environmental Factors

Formaldehyde, which is recognized as a harmful indoor air pollutant for human health, is emitted mainly from urea-formaldehyde resin in wood products. Chamber tests are used to evaluate formaldehyde emission rates from these products. However, there is no available formaldehyde standard reference emission source to assess the performance of chamber testing systems. In this work, a LIFE (liquid-inner tube diffusion-film-emission) formaldehyde reference is described. The formaldehyde source consists of a polytetrafluoroethene (PTFE) tube that holds a formaldehyde–water solution with a concentration of 16 g formaldehyde per 100 mL water, with a thin polydimethylsiloxane (PDMS) film cover. Formaldehyde emission parameters for the PDMS film (diffusion coefficient and partition coefficient) were determined experimentally, thereby enabling the prediction of the formaldehyde emissions from the source for use as a reference value in a chamber. Chamber tests were conducted in a 51 L stainless steel ventilated chamber. The impacts of temperature and relative humidity on the emissions were investigated. Results show the LIFE’s chamber test results match those predicted by a mass transfer model. As a result, this formaldehyde source may be used to generate a reference concentration in product emission testing chambers, thereby providing a powerful tool to evaluate the performance of the chamber testing systems