Loading and air exchange rate

Table VIII. Particleboard - Loading and Air Exchange Rate Effects on Chamber Concentration...

Effects of loading and air exchange rates on chamber formaldehyde concentrations can be predicted. 

In 1996, investigations on PVC products were performed in test chambers under defined conditions [86]. At room temperature the DEHP concentration was below 0.1 pg m At higher temperatures the chamber values increased as expected. The maximum value was 5.2 pg m (60 °C). Wilke and Jann [87] described test chamber investigations on wallpapers containing DEHP. In tests over 28 days in chambers of 1 m (23 °C, 45% relative humidity, air exchange rate 1 h loading 1 m m ) DEHP was not detectable with a detection limit of 0.35 pg m Only when the temperature was increased to 40 °C were DEHP values of up to approximately 2 pg m measured. 

Formaldehdye generation and recovery studies 3.) Air exchange measurement techniques 4.) Preconditioning of test boards 5.) Temperature effect on chamber formaldehyde concentrations 6.) Relationship of popular quality control test methods to the large chamber 7.) Loading, air exchange rate, and wood product combination effects on chamber formaldehyde concentrations 8.) Chamber Round Robin studies between Georgia-Pacific s chamber and other outside lab chambers 9.) Chamber concentrations and its relationship to actual field measurements. 

Air exchange rate, effects of loading and, chamber concentration, 167-173... 

The product/material to be examined is tested with regard to temperature, relative humidity, air exchange rate, air velocity and product loading factor (ratio of exposed surface area of the test specimen to the free emission test chamber volume). It is exam-... 

The last include wet and dry deposition of particles and solutes and gas exchange across the air-sea interface. Because of proximity to source, coastal waters tend to be more polluted than the open ocean. A notable exception is the worldwide acidification of surface waters caused by CO2 emissions. Of all the coastal waters, estuaries tend to be the most impacted. This is due to high rates of pollutant loading and to natural processes that act to concentrate these pollutants in the local sediments and biota. This is most unfortunate as estuarine waters support the world s largest fisheries and are where recreation is concentrated. 

Air measurement in a chamber or cell initially produces the concentration C(t) at the time t of the measurement. To enable better comparability of the measured data the specific emission rate (SER) independent of air exchange and loading is to be preferred. The SER describes the product-specific emission behavior, for example, as area-specific emission rate (SERA) with the unit pg/(rn h) or as unit-based specific emission rate (SERu) with the unit gg/(unit h). 

The experimental evaluation of other effects associated with the operative temperatures and stoichiometric ratio is performed in a range of pressure around 130 kPa, using the side channel air compressor whose characteristics are described in Table 7.1. The effect of the stack temperature on the voltage measured at the stack terminals is shown in Fig. 7.8. In this case, the temperamre is controlled by varying the water flow rate in the heat exchanger shell while the air flow rate and humidification conditions are the same as those of Fig. 7.7. It can be observed that a decrease in temperamre from 346 to 305 K determines a voltage reduction <10% up to 70% of load (200 A), while a satisfactory stack behavior at 313 K is detected in almost all load conditions (see Sect. 3.3). Then, the effect of the stoichiometric ratio is verified for three different loads at the stack and humidification temperature of 313 K. From Fig. 7.9, it can be noted that values of R higher than 2 are... 

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