A New Clean Air Delivery Rate Test Applied to Five Portable Indoor Air Cleaners

Abstract

Air pollution has been recognised as one of the major risk factors for the global burden of disease. In modern society the majority of the exposure occurs indoors where people spend most of their time. Indoor air quality may be improved with portable air cleaners utilizing various cleaning techniques, such as filtration, electrostatic precipitation, and ionization. The objective of this study was to quantify air cleaner particle removal by particle size resolved clean air delivery rates (CADR). This was obtained by utilizing particle concentration measurements and indoor aerosol modeling. Our test protocol was applied to five air cleaners designed for household and office use. For particles with diameters above 100 nm and at the chosen settings, the CADR was around 40 m 3 /h for an ion generator, around 70 m 3 /h for an electrostatic precipitator, and ranging from 100 to almost 300 m 3 /h for the three filter-based air cleaners. Similar performances were obtained for ultrafine particles, except for the ion generator that performed better in this size range.

Indoor Air Quality Management by Combined Ventilation and Air Cleaning: An Experimental Study

“…The values of CADR against particle sizes were of similar magnitude as recently reported by Mølgaard et al (2014). The VOC removal efficiency as reflected by CADR and E was substantially lower, compared to the particle removal efficiency.…”

“…Different power requirements seemed to be associated with the efficiency of VOC removal, as discussed below. Based on these technical parameters, the tested cleaners were comparable to those used in earlier studies (Shaughnessy and Sextro, 2006;Waring et al, 2008;Mølgaard et al, 2014;Noh and Oh, 2015).…”

“…The CADR is considered as the best available metric to compare portable air cleaners because it takes into account the flow rate through the air cleaner, the volume of the test room, and the pollutant removal efficiency (Shaughnessy and Sextro, 2006). In case of particles, the CADR was found around 40 m 3 h -1 for an ion generator, 70 m 3 h -1 for an electrostatic precipitator, and ranging from 100 to almost 300 m 3 h -1 for the three filter-based air cleaners for particles with diameters above 100 nm (Mølgaard et al, 2014). At the same time, portable air cleaners are much less efficient in removing organic compounds from indoor air.…”

“…) for a certain pollutant (further represented as CADR PNC and CADR VOC ), V is the volume of the chamber (m 3 ), k e is the total decay rate, including both cleaner and ventilation (h -1 ), k n is the natural decay rate, including only ventilation (h -1 ), k c is decay rate of the pollutant concentration, reflecting loss of pollutants due to deposition or adsorption (h -1 ), which was indicated as an important parameter by (Mølgaard et al, 2014).…”

Testing the near field/far field model performance for prediction of particulate matter emissions in a paint factory

“…53,54 There are various source characterization studies made both for consumer products and occupational processes. [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71] Similarly particle sinks can be assessed according to the model by Mølgaard et al 72 made for indoor air cleaners. Some of these scenarios could potentially be covered with exposure assessment tools such as the ConsExpo REACH tool, but this tool may not be applicable to larger scale industrial exposure scenarios.…”