Working parameter selection and analysis of radiant floor cooling combined with desk-based task/ambient conditioning (TAC) system

Abstract

As a form of task/ambient conditioning (TAC) system, task ventilation is an effective way to control the micro environment of workplace. In response, we have proposed and investigated a radiant floor cooling combined with desk-based TAC system in order to accomplish complementary advantages of radiant floor system and TAC system. Up to now, very few studies on this system have been found in existing literatures. In this paper, appropriate working parameters of the system are examined by numerical simulation method. To improve simulation accuracy, experiments were simulated in reference by applying three turbulence models and two radiation models. It turned out that the standard k–ɛ model combined with Discrete Ordinates (DO) model boasts the best accuracy as is revealed by the comparison between simulated results with the experimental. On this basis, a simulation of an office adopting the system was performed. According to analysis of the influence of different radiant panel temperatures and air supply parameters of TAC system on the thermal environment based on calculated results, the appropriate working parameters that meet the thermal comfort requirements are obtained, which can be used as a reference for the design of the system. The TRNSYS software was employed to simulate the operation energy consumption of the composite system in the office building, and the design parameters of the comprehensive consideration of comfort and energy saving are put forward in the present study.

Practical application: For the conference room applied a radiant floor cooling combined with TAC system, this paper analyzed the impact of floor surface temperatures, task air supply temperature and task air supply temperature to the occupants workplace’s thermal environment and energy consumption of the system, and obtained the design parameters which comprehensive considered comfort and energy consumption. The research results of this paper can provide guideline for the design and selection of the working parameters for the conference room applied a radiant floor cooling combined with TAC system.

Keywords

Radiant floor cooling task/ambient conditioning (TAC)numerical simulation thermal comfort working parameters

Get full access to this article

View all access options for this article.

References

Niu

Zhang

Zuo

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

Niu

Kooi

JVD

Rhee

HVD

. Energy saving possibilities with cooled-ceiling systems. Energy Build 1995; 23: 147–158.

Imanari

Omori

Bogaki

. Thermal comfort and energy consumption of the radiant ceiling panel system.: comparison with the conventional all-air system. Energy Build 1999; 30: 167–175.

Zhao

Liu

X-H

Jiang

. On-site measured performance of a radiant floor cooling/heating system in Xi’an Xianyang International Airport. Solar Energy 2014; 108: 274–286.

Yajun L, Zuiliang M and Pinghua Z. Heating,ventilating and air conditioning. Beijing: China Building Industry Press, 2007.

Zhang

Liu

Zhao

. Entransy analysis and application of a novel indoor cooling system in a large space building. Int J Heat Mass Transfer 2015; 85: 228–238.

Causone

Baldin

Olesen

. Floor heating and cooling combined with displacement ventilation: possibilities and limitations. Energy Build 2010; 42: 2338–2352.

Bauman FSP and Arens EA. Task/ambient conditioning systems: engineering and application guidelines. Center for Environmental Design Research, University of California, Berkeley, CA, 1996.

Melikov

Skwarczynski

Kaczmarczyk

. Use of personalized ventilation for improving health, comfort, and performance at high room temperature and humidity. Indoor Air 2013; 23: 250–263.

10.

Zhang

Arens

Kim

. Comfort, perceived air quality, and work performance in a low-power task–ambient conditioning system. Build Environ 2010; 45: 29–39.

11.

Makhoul

Ghali

Ghaddar

. Thermal comfort and energy performance of a low-mixing ceiling-mounted personalized ventilator system. Build Environ 2013; 60: 126–136.

12.

Ning

Dongmei

Mingyin

. Experimental and numerical studies on the performance evaluation of a bed-based task/ambient air conditioning (TAC) system. Appl Energy 2014; 136: 956–967.

13.

Mao

Pan

Deng

. Thermal, ventilation and energy saving performance evaluations of a ductless bed-based task/ambient air conditioning (TAC) system. Energy Build 2013; 66: 297–305.

14.

Pan

Chan

Xia

. Performance evaluation of a novel bed-based task/ambient conditioning (TAC) system. Energy Build 2012; 44: 54–62.

15.

Bauman

Arens

Tanabe

. Testing and optimizing the performance of a floor-based task conditioning system. Energy Build 1995; 22: 173–186.

16.

Bauman

Zhang

Arens

. Localized comfort control with a desktop task conditioning system: laboratory and field measurements. Center Built Environ 1993.

17.

Bauman FS, Carter TG, Baughman AV, et al. Field study of the impact of a desktop task/ambient conditioning system in office buildings. ASHRAE Transactions 1998, 104: 1153.

18.

Zheng G, Jing Y, Huang H, et al. Thermal comfort and indoor air quality of task ambient air conditioning in modern office buildings/2009 International Conference on Information Management, Innovation Management and Industrial Engineering. IEEE 2009; 2: 533–536.

19.

Yan D. Research on airflow patterns and control strategies of the hybrid system with radiant cooling and dedicated outdoor air. Tianjin University, 2012.

20.

Olesen

. Radiant floor cooling systems. ASHRAE J 2008; 50: 16–16.

21.

ASHRAE: Fundamentals handbook. Atlanta, GA: ASHRAE, 1993, p.816.

22.

ISO. Moderate Thermal Environments: Determination of the PMV and PPD Indices and Specification of the Conditions for Thermal Comfort. ISO, 1984.

23.

Aziz

Gad Ia

Mohammed

ESFA

. Experimental and numerical study of influence of air ceiling diffusers on room air flow characteristics. Energy Build 2012; 55: 738–746.