Influence of sensible cooling load on indoor air distribution in an office room with ceiling cooling and mixing ventilation

Abstract

A mixing ventilation system integrated with a ceiling cooling system is a potential advanced heating, ventilation and air conditioning system for modern office buildings with a high sensible cooling load. This paper presents an evaluation of the effect of sensible cooling load on the indoor air distribution in a typical office room with mixing ventilation and ceiling cooling. The vertical distributions of indoor air temperature, air velocity and contaminant (CO₂) concentration were evaluated by the vertical air temperature difference, turbulence intensity and contaminant removal effectiveness. The results showed that when the chilled ceiling surface temperature was increased from 15.0°C to 23.0°C and supply air temperature was decreased from 22.0°C to 19.0°C, the average vertical air temperature difference, turbulence intensity and contaminant removal effectiveness were 0.2°C–0.3°C, 27%–32% and 0.53–0.81 as both internal and external sensible cooling loads were 41.5 W/m². Moreover, these evaluation indices varied slightly as the external sensible cooling load was increased from 41.5 W/m² to 69.5 W/m², whereas they varied greatly as the internal sensible cooling load was increased from 41.5 W/m² to 69.5 W/m². Hence, the external sensible cooling load could slightly affect the indoor air distribution, whereas the internal sensible cooling load could clearly affect the indoor air distribution in an office room with mixing ventilation and ceiling cooling.

Keywords

Mixing ventilation Ceiling cooling Indoor air distribution Sensible cooling load

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References

Niu

Kooi

. Indoor climate in rooms with cooled ceiling systems. Build Environ 1994; 29: 283–290.

Miriel

Serres

Trombe

. Radiant ceiling panel heating-cooling systems: experimental and simulated study of the performances, thermal comfort and energy consumptions. Appl Therm Eng 2002; 22: 1861–1873.

Watson

Kirby

. Radiant heating and cooling handbook. New York, NY: McGraw Hill Professional, 2002.

Jan

Olesen

Petras

. Low temperature heating and high temperature cooling. Brussels: REHVA, 2009.

Rhee

Kim

. A 50 year review of basic and applied research in radiant heating and cooling systems for the built environment. Build Environ 2015; 91: 166–190.

Teodosiu

Ilie

Teodosiu

. Numerical prediction of thermal comfort and condensation risk in a ventilated office, equipped with a cooling ceiling. Energy Procedia 2016; 85: 550–558.

Lipczynska

Kaczmarczyk

Melikov

. Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling. Build Environ 2015; 92: 603–614.

Jeong

Mumma

. Ceiling radiant cooling panel capacity enhanced by mixed convection in mechanically ventilated spaces. Appl Therm Eng 2003; 23: 2293–2306.

Jeong

Mumma

. Impact of mixed convection on ceiling radiant cooling panel capacity. HVAC R Res 2003; 9: 251–257.

10.

Niu

Zhang

Zuo

. Energy savings potential of chilled-ceiling combined with desiccant cooling in hot and humid climates. Energy Build 2002; 34: 487–495.

11.

Mustakallio

Bolashikov

Kostov

Melikov

Kosonen

. Thermal environment in simulated offices with convective and radiant cooling systems under cooling (summer) mode of operation. Build Environ 2016; 100: 82–92.

12.

Mustakallio

Bolashikov

Rezgals

Lipczynska

Melikov

Kosonen

. Thermal environment in a simulated double office room with convective and radiant cooling systems. Build Environ 2017; 123: 88–100.

13.

Novoselac

Srebric

. A critical review on the performance and design of combined cooled ceiling and displacement ventilation systems. Energy Build 2002; 34: 497–509.

14.

Riffat

Zhao

Doherty

. Review of research into and application of chilled ceilings and displacement ventilation systems in Europe. Int J Energy Res 2004; 28: 257–286.

15.

Behne

. Indoor air quality in rooms with cooled ceilings: mixing ventilation or rather displacement ventilation? Energy Build 1999; 30: 155–166.

16.

Wang

Zhen

. Performance comparison between mixing ventilation and displacement ventilation with and without cooled ceiling. Eng Computat 2006; 23: 218–237.

17.

Huang

Chen

. Comparison of different types of ventilation in combined system of chilled ceiling to investigate the effect of indoor air quality. Contamination Control Air-Condition Technol 2008; 2: 18–23. (in Chinese)

18.

Esmail

Kwok

Hansjürg

. A review of high temperature cooling systems in tropical buildings. Build Environ 2016; 96: 237–249.

19.

Mustakallio

Kosonen

Melikov

. The effects of mixing air distribution and heat load arrangement on the performance of ceiling radiant panels under cooling mode of operation. Sci Technol Built Environ 2016; 23: 1–15.

20.

Gao

Wang

Tian

. Impact of chilled ceiling in a high sensible cooling load room with underfloor air distribution. Sci Technol Built Environ 2019; 25: 705–715.

21.

Gao

Wang

Tian

. Indoor air distribution in a room with underfloor air distribution and chilled ceiling: Effect of ceiling surface temperature and supply air velocity. Indoor Built Environ 2020; 29: 151–162. DOI:10.1177/1420326X19853605

22.

Kazanci O, Khovalyg D, Lida T, Uno Y, Ukiana T and Olesen B. Experimental comparison of the thermal indoor environmental created by a radiant, and a combined radiant and convective cooling system. In: Proceedings of RoomVent and ventilation, Espoo, Finland, 2–5 June 2018, 2018, pp.223-228.

23.

Huan

Wang

Lin

Wang

. An experimental investigation into stratum ventilation for the cooling of an office with asymmetrically distributed heat gains. Build Environ 2016; 110: 76–88.

24.

Kline

McClintock

. Describing uncertainties in single-sample experiments. Mech Eng 1953; 75: 3–9.

25.

ISO 7730:2005. Ergonomics of the thermal environment – analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. Brussels: European Committee for Standardization, 2005.

26.

Melikov

. Local thermal discomfort due to draft and vertical temperature difference in rooms with displacement ventilation. ASHRAE Transact 1989; 95: 1050–1057.

27.

Mundt

Mathisen

Nielsen

Moser

. Ventilation effectiveness. REHVA guidebook. Brussels: REHVA, 2004.

28.

Cao

Cen

Zhang

Feng

. Study on the impacts of human walking on indoor particles dispersion using momentum theory method. Build Environ 2017; 126: 195–206.

29.

Cao

Ren

. Ventilation control strategy using low-dimensional linear ventilation models. Build Environ 2018; 144: 316–333.

30.

Deng

Feng

Cao

. Influence of air change rates on indoor CO₂ stratification in terms of Richardson number and vorticity. Build Environ 2018; 129: 74–84.