This paper presents general guidance on designing for thermal comfort in combined chilled ceiling/displacement ventilation environments. Thermal comfort measurements involving 184 human subjects were carried out in a laboratory- based test room, constructed to resemble a normal office and equipped with a combined chilled ceiling and wallmounted displacement ventilation system.
Experts on animal production housing design were surveyed to determine current knowledge, identify potential control measures, and define research and development needs on indoor air quality in production animal facilities. Results indicated that for larger, more mature animals, properly designed and controlled natural ventilation systems are effective in providing good environments. For colder climates and more sensitive animals, a combined system with mechanical ventilation for cold weather and natural ventilation for warm weather works well.
In this paper, new requirements for the characteristics of anemometers used for low-velocity measurements indoors, as well as requirements for the signal processing, are presented The static calibration, dynamic response, and temperature compensation of the anemometers, as well as the directional sensitivity and the design of the velocity transducer, are considered, together with the period and the sampling rate of the measurements.
Unsolicited complaints from 23,500 occupants in 690 commercial buildings were examined with regard to absolute and relative frequency of complaints, temperatures at which thermal sensation complaints (too hot or too cold) occurred, and response times and actions. The analysis shows that thermal sensation complaints are the single most common complaint of any type and that they are the overwhelming majority of environmental complaints.
Thermal anemometers with heated velocity sensors are mostly used for low-velocity measurements in rooms. The heated velocity sensor generates an upward, free convection flow that interacts with the airflow where measurements are to be performed and, thus, has an impact on the accuracy of the velocity measurements. Tests were performed with four anemometers available on the market to identify this impact in an airflow with a constant velocity and in an airflow with a periodically fluctuating velocity.
A study was made of the impact of well-documented random velocity fluctuations and periodic temperature fluctuations with different amplitudes and frequencies on the accuracy of the mean velocity and the standard deviation of the velocity measured by three low-velocity anemometers with omnidirectional probes. The anemometers were tested in an airflow at 225 combinations of mean velocity, amplitude of the velocity, and temperature fluctuations, as well as frequency of the temperature fluctuations, as identified during field measurements.
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