The FLEC® has been validated and used in research for many years.
Below is a publication list of journal articles, abstracts, poster or oral presentations where the FLEC or CHEMATEC’s other products have been in focus.
If you have anything that can be added to the list, we encourage you to contact CHEMATEC.
2016 |
Rizk, Malak; Verriele, Marie; Mendez, Maxence; Blond, Nadège; Dusanter, Sébastien; Schoemaecker, Coralie; Blondeau, Patrice; Calvé, Stéphane Le; Locoge, Nadine Fast sorption measurements of VOCs on building materials: Part 2 – Comparison between FLEC and CLIMPAQ methods Journal Article In: Building and Environment, vol. 99, pp. 239 - 251, 2016, ISSN: 0360-1323. Abstract | Links | BibTeX | Tags: Building materials, CLIMPAQ, FLEC, Indoor air quality, Model, Sorption @article{RIZK2016239,A new method was developed to measure on the field VOC sorption coefficients (ka; kd) on the surface of a material by coupling a Field and Laboratory Emission Cell (FLEC) to a Proton Transfer Reaction-Mass Spectrometer (PTR-MS) as presented in the first part of this study. In this second part, the method is compared to the classical method based on a CLIMPAQ chamber coupled to an on-line GC analyzer. Different models were used to determine the sorption parameters from experimental data taking into account the sink effect on empty chamber walls and the presence of a boundary-layer. Determined sorption equilibrium coefficients Ke (ka/kd) for a mixture of BTEX on a gypsum board was found to be in good agreement between both methods. However, the CLIMPAQ method seems to be less robust than the FLEC method in the determination of sorption coefficients since more than one couple of (ka; kd), showing the same ratio Ke can retrieve the same CLIMPAQ experimental data. Giving this result, the question arises about the reliability of the literature data determined using emission test chamber which could be one of the reasons behind the discrepancies found between experimental indoor concentrations and predicted ones using chamber derived parameters. |
2014 |
Vibenholt, Anni; Clausen, Per Axel; Wolkoff, Peder Ozone reaction characteristics of indoor floor dust examined in the emission cell “FLEC” Journal Article In: Chemosphere, vol. 107, pp. 230 - 239, 2014, ISSN: 0045-6535. Abstract | Links | BibTeX | Tags: Aldehydes, FLEC, Floor dust, Indoor air, Ozone, Reaction rate @article{VIBENHOLT2014230,Ozone reacts with C–C double bonds in common indoor VOCs and SVOCs contained in indoor dust and may be catalytically degraded on dust surfaces. The reaction between floor dust and ozone was investigated in the FLEC emission cell at different ozone concentrations and relative humidities (0%, 25%, and 50% RH). One gram of dust was spread on a clean stainless steel plate which was placed in the FLEC. Steady state reaction rate (kDust) at 2.2ppm ozone was determined for four different floor dust samples collected in Danish homes and offices. This high concentration was necessary in order to measure and determine the consumption in the outlet air from the FLEC. Measurements were corrected for FLEC wall effects by subtraction of the steady state reaction rate between ozone and a FLEC on a stainless steel plate without dust (kFLEC). The composition of organic compounds in the dust was analyzed by pressurized liquid extraction and thermal desorption GC–MS before and after ozone exposure. kFLEC was independent of the ozone concentration and the reaction was treated as first order. The same was indicated for kDust since it remained unchanged at 2.2 and 1.6ppm ozone for one dust sample. However, the measured kDust in the FLEC should be considered an average rate constant due to the FLEC geometry. kDust was in the range 0.039–0.14s-1 pr. g dust at 50% RH. kDust was 3 times higher at 25% RH than at 50% RH and 6 times higher than at 0% RH. The inhomogeneity of the dust was assessed by experiments in triplicate with a new portion of dust each time. The relative standard deviation of kDust at 50% RH was 6–20%. The major identified compounds before and after ozone exposure included aldehydes, saturated and unsaturated linear alkanoic acids, benzoic acid and their methyl esters, dimethyl esters, phthalates and traces of α-pinene and limonene. Substantial increase of C7–C9 aldehydes was observed after ozone exposure. |
Vibenholt, Anni; Clausen, Per Axel; Wolkoff, Peder Ozone reaction characteristics of indoor floor dust examined in the emission cell “FLEC” Journal Article In: Chemosphere, vol. 107, pp. 230-239, 2014, ISSN: 0045-6535. Abstract | Links | BibTeX | Tags: Aldehydes, FLEC, Floor dust, Indoor air, Ozone, Reaction rate @article{Vibenholt2014d,Ozone reacts with C–C double bonds in common indoor VOCs and SVOCs contained in indoor dust and may be catalytically degraded on dust surfaces. The reaction between floor dust and ozone was investigated in the FLEC emission cell at different ozone concentrations and relative humidities (0%, 25%, and 50% RH). One gram of dust was spread on a clean stainless steel plate which was placed in the FLEC. Steady state reaction rate (kDust) at 2.2ppm ozone was determined for four different floor dust samples collected in Danish homes and offices. This high concentration was necessary in order to measure and determine the consumption in the outlet air from the FLEC. Measurements were corrected for FLEC wall effects by subtraction of the steady state reaction rate between ozone and a FLEC on a stainless steel plate without dust (kFLEC). The composition of organic compounds in the dust was analyzed by pressurized liquid extraction and thermal desorption GC–MS before and after ozone exposure. kFLEC was independent of the ozone concentration and the reaction was treated as first order. The same was indicated for kDust since it remained unchanged at 2.2 and 1.6ppm ozone for one dust sample. However, the measured kDust in the FLEC should be considered an average rate constant due to the FLEC geometry. kDust was in the range 0.039–0.14s-1 pr. g dust at 50% RH. kDust was 3 times higher at 25% RH than at 50% RH and 6 times higher than at 0% RH. The inhomogeneity of the dust was assessed by experiments in triplicate with a new portion of dust each time. The relative standard deviation of kDust at 50% RH was 6–20%. The major identified compounds before and after ozone exposure included aldehydes, saturated and unsaturated linear alkanoic acids, benzoic acid and their methyl esters, dimethyl esters, phthalates and traces of α-pinene and limonene. Substantial increase of C7–C9 aldehydes was observed after ozone exposure. |
2010 |
Kim, Sumin Control of formaldehyde and TVOC emission from wood-based flooring composites at various manufacturing processes by surface finishing Journal Article In: Journal of Hazardous Materials, vol. 176, no. 1, pp. 14 - 19, 2010, ISSN: 0304-3894. Abstract | Links | BibTeX | Tags: Engineered flooring, FLEC, Formaldehyde, Laminate flooring, VOCs @article{KIM201014,This paper assesses the reproducibility of testing formaldehyde and TVOC emission behavior from wood flooring composites bonded by urea–formaldehyde resin at various manufacturing steps for surface finishing materials. The surface adhesion step of laminate flooring for this research was divided into two steps; HDF only and HDF with LPMs. In the case of engineered flooring, the manufacturing steps were divided into three steps; plywood only, fancy veneer bonded on plywood and UV coated on fancy veneer with plywood. Formaldehyde and VOCs emission decreased at the process of final surface finishing materials; LPMs were applied on the surface of HDF for laminate flooring. Although emissions increased when fancy veneer was bonded onto plywood in the case of engineered flooring, emission was dramatically reduced up to similar level with plywood only when final surface finishing; UV-curable coating was applied on fancy veneer. This study suggests that formaldehyde and VOCs emission from floorings can be controlled at manufacturing steps for surface finishing. |
Clausen, Per Axel; Liu, Zhe; Xu, Ying; Kofoed-Sørensen, Vivi; Little, John C Influence of air flow rate on emission of DEHP from vinyl flooring in the emission cell FLEC: Measurements and CFD simulation Journal Article In: Atmospheric Environment, vol. 44, no. 23, pp. 2760 - 2766, 2010, ISSN: 1352-2310. Abstract | Links | BibTeX | Tags: CFD, Chamber, DEHP, Emission, FLEC, PVC @article{CLAUSEN20102760,The emission of di-(2-ethylhexyl)phthalate (DEHP) from one type of vinyl flooring with ∼15% (w/w) DEHP as plasticizer was measured at 22 °C in five FLECs + one blank FLEC (Field and Laboratory Emission Cell). Initially, the flow through all FLECs was 450 ml min−1. After 689 days the flows were changed to 1000 ml min−1, 1600 ml min−1, 2300 ml min−1, and 3000 ml min−1, respectively, in four FLECs, and kept at 450 ml min−1 in one FLEC. Air samples were collected from the effluent air at regular intervals. After 1190 days the experiments were terminated and the interior surfaces of all six FLECs were rinsed with methanol to estimate the internal surface concentrations of DEHP. The DEHP air concentration and specific emission rate (SER) at steady state was estimated for the five different flow rates. The steady-state concentrations decreased slightly with increasing air flow with only the two highest flow rates resulting in significantly lower concentrations. In contrast, the SERs increased significantly. Despite large variation, the internal surface concentrations appeared to decrease slightly with increasing FLEC flow. Computational fluid dynamic (CFD) simulations suggest that the interior gas and surface concentrations were roughly uniform for the low flow case (450 ml min−1), under which, the partitioning between the FLEC internal surface and chamber air was examined. Although paired t-tests showed no difference between CFD and experimental results for DEHP air concentrations and SERs at steady-state conditions, CFD indicated that the experimental DEHP surface concentrations in the FLECs were underestimated. In conclusion, the experiments showed that the emission of DEHP from vinyl flooring is subject to “external” control and that the SER is strongly and positively dependent on the air exchange rate. However, the increased SER almost compensates for the decrease in gas-phase concentration caused by the increased air exchange. |
2004 |
Luo, R; Niu, J L Determination of water vapor diffusion and partition coefficients in cement using one FLEC Journal Article In: International Journal of Heat and Mass Transfer, vol. 47, no. 10, pp. 2061 - 2072, 2004, ISSN: 0017-9310. Abstract | Links | BibTeX | Tags: Cement, Diffusion coefficient, FLEC, Mass diffusion, Partition coefficient, Water vapor @article{LUO20042061,Water vapor diffusion and partition coefficients in cement slabs were determined by solving the inverse problem of one-dimensional unsteady mass diffusion based on measurements of the concentration of water vapor in a field and laboratory emission cell (FLEC) system. A solution for multi-process mass diffusion was obtained to analyze the influence of the non-uniform initial water vapor concentration distribution on the determination of diffusion and partition coefficients. The main factors affecting the accuracy of the diffusion and partition coefficients were discussed. Good agreement between the measured data and the predictions of the inverse problems showed that the mass diffusion in the cement slabs could be described accurately by the one-dimensional model. |
1999 |
Meininghaus, Roman; Salthammer, Tunga; Knöppel, Helmut Interaction of volatile organic compounds with indoor materials—a small-scale screening method Journal Article In: Atmospheric Environment, vol. 33, no. 15, pp. 2395 - 2401, 1999, ISSN: 1352-2310. Abstract | Links | BibTeX | Tags: FLEC, Indoor air, Mass transport, Permeability, Sink @article{MEININGHAUS19992395,Indoor air pollution caused by volatile organic compounds (VOCs) may affect the health and well-being of inhabitants. Uptake and release of these compounds by and from indoor materials alter their concentrations in indoor air: uptake will lower peak concentrations, whereas subsequent (slow) release at lower concentration levels will prolong the presence of VOCs in indoor air. An experimental set-up has been implemented where indoor materials are placed as a “membrane” separating two air compartments. Both compartments – consisting of Field and Laboratory Emission Cells FLECs – are constantly flushed with air, one air stream containing a mixture of 20 VOCs, and concentrations in both compartments are measured after 1 h. Ten materials usually covering extensive surfaces indoors were consecutively exposed to the vapour mixture at concentration levels typically found in indoor environments. Under the chosen experimental conditions, five of these materials exhibited a permeability high enough that VOCs could be detected on the other side. Mass transport of VOCs into and through indoor materials has therefore been confirmed by experiment. The set-up allows for a quick screening of indoor materials with respect to their sorption capacity and permeability. |
1998 |
Wolkoff, Peder Impact of air velocity, temperature, humidity, and air on long-term voc emissions from building products Journal Article In: Atmospheric Environment, vol. 32, no. 14, pp. 2659 - 2668, 1998, ISSN: 1352-2310. Abstract | Links | BibTeX | Tags: Air velocity, building products, emission testing, FLEC, relative humidity, repeatability, temperature, VOCs (volatile organic compounds) @article{WOLKOFF19982659,The emissions of two volatile organic compounds (VOCs) of concern from five building products (BPs) were measured in the field and laboratory emission cell (FLEC) up to 250d. The BPs (VOCs selected on the basis of abundance and low human odor thresholds) were: nylon carpet with latex backing (2-ethylhexanol, 4-phenylcyclohexene), PVC flooring (2-ethylhexanol, phenol), floor varnish on pretreated beechwood parquet (butyl acetate, N-methylpyrrolidone), sealant (hexane, dimethyloctanols), and waterborne wall paint on gypsum board (1,2-propandiol, Texanol). Ten different climate conditions were tested: four different air velocities from ca. 1cms-1 to ca. 9cms-1, three different temperatures (23, 35, and 60°C), two different relative humidities (0% and 50% RH), and pure nitrogen instead of clean air supply. Additionally, two sample specimen and two different batches were compared for repeatability and homogeneity. The VOCs were sampled on Tenax TA and determined by thermal desorption and gas chromatography (FID). Quantification was carried out by individual calibration of each VOC of concern. Concentration/time profiles of the selected VOCs (i.e. their concentration decay curves over time) in a standard room were used for comparison. Primary source emissions were not affected by the air velocity after a few days to any great extent. Both the temperature and relative humidity affected the emission rates, but depended strongly on the type of BP and type of VOC. Secondary (oxidative) source emissions were only observed for the PVC and for dimethyloctanols from the sealant. The time to reach a given concentration (emission rate) appears to be a good approach for future interlaboratory comparisons of BP’s VOC emissions. |
Uhde, E; Borgschulte, A; Salthammer, T Characterization of the field and laboratory emission cell—FLEC: Flow field and air velocities Journal Article In: Atmospheric Environment, vol. 32, no. 4, pp. 773 - 781, 1998, ISSN: 1352-2310. Abstract | Links | BibTeX | Tags: Air velocity, Chambers, emission rate, FLEC, flow field, VOC @article{UHDE1998773,Abstract The Field and Laboratory Emission Cell (FLEC) has been designed for VOC emission testing of material surfaces. Knowledge about the air flow field in the cell compartment is highly desired, as the air velocity at the sample surface may considerably influence the emission behaviour. A simple mathematical approach of flow theory predicted an unevenly distributed air flow into the FLEC. This could be confirmed by air velocity measurements using a self-constructed hot-wire anemometer. With a total flow of 250 ml min−1, air velocities measured at the surface ranged from ⩽ 0.1 to 0.9 cm s−1. A surface area of very low air velocities was detected in the FLEC centre with a radius of ≈20 mm. A VOC emission test using a simulated punctual source yielded different emission rates at different locations in the cell compartment. |