Thermal environment in a simulated double office room with convective and radiant cooling systems

Abstract The thermal environment in a double office room obtained with chilled beam (CB), chilled beam with radiant panel (CBR), chilled ceiling with ceiling installed mixing ventilation (CCMV) and overhead mixing total volume ventilation (MTVV) under summer (cooling) condition was compared. Design (peak) and usual (average) heat load from solar radiation, office equipment, lighting and occupants was simulated, respectively at 62 W/m2 and 38 W/m2 under four different workstation layouts. Air temperature, globe (operative) temperature, radiant asymmetry, air velocity and turbulent intensity were measured and draught rate was calculated. Manikin-based equivalent temperature (MBET) was determined by using two thermal manikins. CCMV provided slightly more uniform thermal environment and the least sensitive to different workstation layouts than the other systems. CB provided a bit higher draught rate levels than CCMV especially in the design heat load cases. With CBR, the thermal environment was found to be between CB and CCMV. MTVV generated high draught level under the tested design heat load cases. All cooling systems generated similar thermal environment in the usual heat load cases. It would be recommended to include the measurement height of 0.05 m in indoor climate testing standards for obtaining more generic view of the draught risk.

[1]  Changyun Wen,et al.  Geometric optimization on active chilled beam terminal unit to achieve high entrainment efficiency. , 2016 .

[2]  Standard Ashrae.  Thermal Environmental Conditions for Human Occupancy , 1992 .

[3]  Bjarne W. Olesen,et al.  Low temperature heating and high temperature cooling: REHVA GUIDEBOOK No 7 , 2007 .

[4]  Sun-Ho Choi,et al.  Thermal uniformity in an open plan room with an active chilled beam system and conventional air distribution systems , 2015 .

[5]  Hannu Koskela,et al.  Air distribution in office environment with asymmetric workstation layout using chilled beams , 2010 .

[6]  Kwang Woo Kim,et al.  A 50 year review of basic and applied research in radiant heating and cooling systems for the built environment , 2015 .

[7]  Risto Kosonen,et al.  The effects of mixing air distribution and heat load arrangement on the performance of ceiling radiant panels under cooling mode of operation , 2017 .

[8]  Hannu Koskela,et al.  Flow pattern and thermal comfort in office environment with active chilled beams , 2012 .

[9]  A. Melikov,et al.  Thermal environment in simulated offices with convective and radiant cooling systems under cooling (summer) mode of operation , 2016 .

[10]  Fred Bauman,et al.  Thermal comfort in buildings using radiant vs. all-air systems: A critical literature review , 2017 .

[11]  Toshiaki Omori,et al.  Thermal comfort and energy consumption of the radiant ceiling panel system.: Comparison with the conventional all-air system , 1999 .

[12]  Shinichi Tanabe,et al.  Indoor Environmental Quality ( IEQ ) Title Evaluating thermal environments by using a thermal manikin with controlled skin surface temperature , 2006 .

[13]  W. D. van Marken Lichtenbelt,et al.  The influence of local effects on thermal sensation under non-uniform environmental conditions — Gender differences in thermophysiology, thermal comfort and productivity during convective and radiant cooling , 2012, Physiology & Behavior.

[14]  Olli Seppänen,et al.  Plane-Air-Jet Corner Zone Modelling in a Room Ventilated by an Active Chilled Beam , 2009 .