Global active noise control has been obtained on the tonal noise from a small centrifugal blower, similar to those used in laptop computers. Compact control systems were investigated for two configurations. The blower was mounted in both a short rectangular duct and in a mock laptop case that was modeled as a two-dimensional rectangular enclosure. Secondary sources and error sensors were locate...

Rice fields host a large diversity of arthropods, but investigating their population dynamics and interactions is challenging. Here we describe the modification and application of a leaf blower-vac for suction sampling of arthropod populations in rice. When used in combination with an enclosure, application of this sampling device provides absolute estimates of the populations of arthropods as ...

Air leakage is an essential factor contributing to overall building performance. It plays a major role in determining energy consumption harsh climates, particularly residential buildings, as it represents significant component of the envelope-induced thermal load. In centrally air-conditioned houses, HVAC system can substantially alter pressure distribution across exterior envelope, reforming ...

In this study, a frequency converter was used to carry out variable frequency control to the compressor with constant frequency of a small 3RT central air-conditioning air-cooled chiller, but the indoor blower and cooled water pump were still kept by constant frequency operation. It is to explore the energy-saving effect of chiller compressor and the cooling fan after being carried out the vari...

BACKGROUND Although heated humidifiers (HHs) are the most efficient humidifying device for mechanical ventilation, some HHs do not provide sufficient humidification when the inlet temperature to the water chamber is high. Because portable and home-care ventilators use turbines, blowers, pistons, or compressors to inhale in ambient air, they may have higher gas temperature than ventilators with ...