Numerical study on temperature stratification in a room with underfloor air distribution system

Indoor thermal stratification and its statistical distribution

“…If the Beta distribution applies, it may be possible to quantify the characteristic curves in Figure 1 for various situations mathematically based on the general model of the Beta distribution. This paper first introduces the Beta distribution and its background theory of the order statistics, then validates the findings by the measurement data of the five warehouse and storage spaces, 20 and eleven published studies [5][6][7][8][9][10][11]13,15,23,38 from the literature. This paper also discusses a few practical implications and applications of these findings.…”

“…In buoyancy-driven ventilated spaces including displacement [5][6][7] and/or underfloor ventilation systems, [8][9][10][11][12] and natural ventilation in large spaces 13,14 during cooling seasons; and 3). In buoyancy-driven ventilated spaces including displacement [5][6][7] and/or underfloor ventilation systems, [8][9][10][11][12] and natural ventilation in large spaces 13,14 during cooling seasons; and 3).…”

“…A 26.4% reduction in gas usage was achieved via destratification in a case study of a distribution warehouse, 21 and a 19.3% reduction of heating energy in a warehouse with five destratification fans was reported by Armstrong et al 22 Said et al 23 predicted that, without destratification, an extra 38% of heating energy was required for aircraft hangar buildings with 8 ˚C temperature difference. 9,28 Thermal stratification also often occurs in other types of buoyancydriven ventilation, such as natural ventilation in large spaces, 14 for which the understanding of the level of stratification and vertical temperature profiles is critical for better control of occupant thermal comfort, ventilation effectiveness, 29 air quality, and energy savings. It is often believed to be due to the booming of e-commerce industries, especially in the Eastern Asia.…”

“…In large industrial warehouses and storage facilities especially in winter seasons 2-4 ;(ii). In buoyancy-driven ventilated spaces including displacement [5][6][7] and/or underfloor ventilation systems, [8][9][10][11][12] and natural ventilation in large spaces 13,14 during cooling seasons; and 3). In a more extreme stratification case, such as during enclosure fire, buoyancy-driven hot smoke rises to form an upper smoke layer on the top of a cold lower air layer.…”

“…In the past decades, many studies have been conducted to understand thermal stratification and its impact on thermal comfort, 27 air quality, 5,6 energy saving, 28 and design and operation of these systems. 9,28 Thermal stratification also often occurs in other types of buoyancydriven ventilation, such as natural ventilation in large spaces, 14 for which the understanding of the level of stratification and vertical temperature profiles is critical for better control of occupant thermal comfort, ventilation effectiveness, 29 air quality, and energy savings. 13 Meanwhile, one of the more extreme cases of thermal stratification is perhaps during building enclosure fires 16,30,31 where buoyancy-driven hot smoke rises to the ceiling level to form an upper smoke layer on the top of a lower cold air layer.…”