Shichao Liu

Shichao Liu
Worcester Polytechnic Institute | WPI · Department of Civil and Environmental Engineering

Ph.D.

About

31
Publications
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730
Citations

Publications

Publications (31)
Article
Full-text available
A vertical thermally stratified environment provides opportunities for improved ventilation effectiveness and energy efficiency, but vertical temperature gradient can also cause local thermal discomfort. ASHRAE 55 and ISO 7730 prescribe a 3 °C/m limit between head and feet for seated persons. However, an increasing amount of evidence suggests that...
Article
Personal thermal comfort prediction modeling has become a trending topic in efforts to improve individual indoor comfort, a notion that is closely related to the design and performance of building systems, especially in sustainable and smart buildings. This research provides a comprehensive overview of data-driven approaches and processes for predi...
Article
Full-text available
Leadership in Energy and Environmental Design (LEED) certified buildings aim to offer a sustainable and healthy building environment. Previous studies have shown mixed and inconsistent results on whether occupants in LEED-certified buildings are more satisfied than in non-LEED-certified counterparts. Those studies are usually based on surveys or qu...
Preprint
Leadership in Energy and Environmental Design (LEED) certified buildings aim to offer a sustainable and healthy built environment. Previous studies have shown mixed and inconsistent results on whether occupants in LEED-certified buildings are more satisfying than in non-LEED-certified counterparts. Those studies usually based on surveys or question...
Article
Full-text available
Cognitive functions refer to the set of brain-based skills to execute tasks of various difficulty levels. As people spend substantial time indoors, the indoor environmental quality (IEQ) influences occupants’ cognitive functions and consequently their learning and work performance. Previous studies have commonly examined the effects of IEQ on integ...
Article
Indoor carbon dioxide (CO2) is a critical parameter in the design and control of ventilation, and in monitoring fresh air levels in buildings. Building occupants are primary sources for indoors CO2, and the rate at which CO2 is generated depends on the occupants’ physical activities. In the past, CO2 generation rates have been indirectly calculated...
Article
Full-text available
ASHRAE Standard 55 has been evolving in recent years to encourage more sustainable building designs and operational practices. A series of changes address issues for which past design practice has been deficient or overly constrained. Some of the changes were enabled by findings from field studies of comfort and energy-efficiency, and others by new...
Article
Full-text available
Inhalation exposure to pure and metabolic elevated carbon dioxide (CO2) concentration has been associated with impaired work performance, lower perceived air quality, and increased health symptoms. In this study, the concentration of metabolic CO2 was continuously measured in the inhalation zone of 41 subjects performing simulated office work. The...
Article
Thermal discomfort is a widespread problem in the built environment, due in part to the variability of individual occupants' thermal preferences. Personal comfort systems (PCS) address this individual variability, and also enable more energy-efficient thermal conditioning in buildings by reducing the need for tight indoor temperature control. This...
Article
Full-text available
A personal comfort model is an approach to thermal comfort modeling, for thermal environmental design and control, that predicts an individual's thermal comfort response, instead of the average response of a large population. We developed personal thermal comfort models using lab grade wearable in normal daily activities. We collected physiological...
Article
The indoor transmission of airborne particles can spread disease and have health-related and even life-threatening effects on occupants, thus necessitating effective ways to locate indoor particle sources. The identification of particle sources from concentration distributions is a difficult task because particles are often released at a time-varyi...
Conference Paper
This paper explores the ability of a low-energy wearable thermal device to improve whole body thermal comfort. The wearable device is a wristwatch-like thermal device with a 25mm * 25mm contact heating and cooling surface. Twenty-three subjects were recruited for testing in a climate chamber, with each participating in three 2-hour tests. The three...
Conference Paper
Full-text available
This paper presents laboratory study of local discomfort at the head and feet influenced by vertical temperature difference. We recruited 98 students and exposed them to four temperature differences (0.4, 2.9, 5.9, 8.3 K) between the head (1.1 m) and ankle (0.1 m) level. Results when subjects are close to whole-body thermal neutrality show that the...
Conference Paper
Full-text available
Existing HVAC systems involve little feedback from indoor occupants, resulting in unnecessary cooling/heating waste and high percentage of discomfort. In addition, large thermal preference variance amongst people requires the development of personal thermal comfort models, rather than group-based methodologies such as predicted mean vote (PMV). Thi...
Article
Full-text available
Ceiling fans provide cooling to indoor occupants and improve their thermal comfort in warm environments at very low energy consumption. Understanding indoor air distribution associated with ceiling fans helps designs when ceiling fans are used. In this study, we systematically investigate the air movement distribution in an unoccupied office room i...
Conference Paper
Full-text available
Indoor environmental quality (IEQ) monitoring is a critical task in building operation, maintenance, and diagnosis. Current approach based on static sensor network is not scalable for IEQ assessment that relies on costly sensing instruments. The study proposes to leverage autonomous mobility to reduce sensing infrastructure cost and enable real-tim...
Article
Indoor environmental quality (IEQ) is a critical aspect of the built environment to ensure occupant health, comfort, well-being and productivity. Existing IEQ monitoring approaches rely on sensor networks deployed at selected locations to collect environmental measurements, and are limited in scale and adaptability due to infrastructure cost and ma...
Article
Full-text available
A cough jet can travel beyond the breathing zone of the source person, and thus, infectious viral- and bacterial-laden particles can be transported from the source person to others in close proximity. To reduce the interpersonal transmission of coughed particles, the objective of this study was to analytically and experimentally investigate the per...
Article
Full-text available
Draft is unwanted local convective cooling. The draft risk model of Fanger et al. (Energy and Buildings 12, 21-39, 1988) estimates the percentage of people dissatisfied with air movement due to overcooling at the neck. There is no model for predicting draft at ankles, which is more relevant to stratified air distribution systems such as underfloor...
Article
Full-text available
The air diffusion performance index (ADPI) concept and its implementation in the diffuser selection guideline (ASHRAE Handbook-Fundamentals, 2009) provide designers a simple method to design overhead-air-distribution systems. However, the current guideline considers only five diffuser types and the range of sensible cooling loads used to develop th...
Article
Full-text available
The objective of this study is to examine the dynamic interaction of a cough jet with different indoor airflow distributions created by linear slot diffusers considering the inter-personal transport of coughed particles. The experimental measurements were performed in a chamber, where the interaction of a cough jet and downward jets with various mo...
Article
Full-text available
Diffuser selection guidance listed in ASHRAE HandbookFundamentals (ASHRAE 2009b) includes Air Diffusion Performance Index values for horizontal high sidewall grills and ceiling linear slot diffusers. However, grills are adjustable at various angles, which generate different airflow patterns in a space and therefore might greatly affect Air Diffusio...
Article
Full-text available
This paper proposes an Air Diffusion Performance Index (ADPI) model for diffuser selection when considering the operation in all-air heating mode. The model uses Fanger's Predicted Mean Vote (PMV) Index adopted by ANSI/ASHRAE Standard-55 to develop the relation between indoor air temperature and velocity. This paper also generates an ADPI selection...
Article
Full-text available
This article presents analytical and experimental results for the velocity distribution and transport of expiratory particles from an artificial cough. The stream-wise penetration distance and velocity field of the cough jet were determined through a combination of dimensionless analysis and experimental techniques. The experiments were conducted i...
Article
Full-text available
Indoor particulate contaminants can be generated in many ways, commonly from human activities, infiltration of HVAC systems, or resuspension from indoor surfaces. Most of these sources are transient and generate nonuniform particle distribution in the space. This study used experimental and numerical methods to investigate the dispersion of three d...
Article
Full-text available
The windcatcher system is a green architectural feature that uses natural ventilation to induce external airflow into residential buildings. This paper presents different configuration and ventilation strategies for the windcatcher to evaluate the performance of the system in relation to ventilation and indoor particle dispersion. A commercial comp...

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Projects (2)
Project
CALLS FOR SUBMISSIONS Assistant Professor Shichao Liu from Worcester Polytechnic Institute, Dr Wenye Hu from the University of Sydney, Dr Manuj Yadav from RWTH Aachen University and I are leading and editing an article collection entitled "Effects of Indoor Environmental Quality on Human Performance and Productivity" in the Open Access Journal Frontiers in Built Environment. This Research Topic welcomes original research studies in the form of laboratory experiments, field tests, and field intervention studies, as well as literature reviews including meta-analyses of previous research outcomes. Submission Deadlines: 06 Oct 2021 Abstract 06 Jun 2022 Manuscript For more information, please visit https://www.frontiersin.org/research-topics/22870/effects-of-indoor-environmental-quality-on-human-performance-and-productivity#overview.
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