Title: Spatial distribution of internal heat gains: A probabilistic representation and evaluation of its influence on cooling equipment sizing in large office buildings

Abstract

Internal heat gains from occupants, lighting, and plug loads are significant components of the space cooling load in an office building. Internal heat gains vary with time and space. The spatial diversity is significant, even for spaces with the same function in the same building. The stochastic nature of internal heat gains makes determining the peak cooling load to size air-conditioning systems a challenge. The traditional conservative practice of considering the largest internal heat gain among spaces and applying safety factors overestimates the space cooling load, which leads to oversized air-conditioning equipment and chiller plants. In this study, a field investigation of several large office buildings in China led to the development of a new probabilistic approach that represents the spatial diversity of the design internal heat gain of each tenant as a probability distribution function. In a large office building, a central chiller plant serves all air handling units (AHUs), with each AHU serving one or more floors of the building. Therefore, the spatial diversity should be considered differently when the peak cooling loads to size the AHUs and chillers are calculated. Finally, the proposed approach considers two different levels of internal heat gains to calculate the peak coolingmore » loads and size the AHUs and chillers in order to avoid oversizing, improve the overall operating efficiency, and thus reduce energy use.« less

Authors:

Zhang, Qi ^[1]; Yan, Da ^[1]; An, Jingjing ^[1]; Hong, Tianzhen ^[2]; Tian, Wei ^[3]; Sun, Kaiyu ^[2]

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+ Show Author Affiliations

1. Tsinghua Univ., Beijing (China)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
3. Tianjin Univ. of Science and Technology, Tianjin (China)

Publication Date:

Wed Jan 18 00:00:00 EST 2017

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Science Foundation of China (NNSFC); USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1532234

Alternate Identifier(s):

OSTI ID: 1396623

Grant/Contract Number:  

AC02-05CH11231; 51521005

Resource Type:

Accepted Manuscript

Journal Name:

Energy and Buildings

Additional Journal Information:

Journal Volume: 139; Journal Issue: C; Journal ID: ISSN 0378-7788

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

29 ENERGY PLANNING, POLICY, AND ECONOMY; 42 ENGINEERING