Chin To Cheung

Chin To Cheung
National University of Singapore | NUS · Department of the Built Environment

PhD in Building Services Engineering

About

36
Publications
15,432
Reads
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867
Citations
Additional affiliations
October 2015 - June 2016
Independent Researcher
Position
  • Research Associate
July 2013 - July 2015
The Hong Kong Polytechnic University
Position
  • Research Assistant
Description
  • To conduct research in building energy simulation, indoor environmental quality and mathematical modelling.

Publications

Publications (36)
Article
Providing indoor environmental quality (IEQ) that satisfies building occupants is an essential component for sustainable and healthy buildings. Existing studies mainly analyse the importance of environmental factors on occupant satisfaction, but often overlook the influence of personal factors. Here, we aim to explore the influence of personal fact...
Article
Several relationships between air temperature and work performance have been published. We reanalysed the one developed in 2006 by Seppänen et al.; which is probably the best known. We found that even when significant, its prediction accuracy is very low (R² = 0.05, MAE = 1.9%, RMSE = 3.1%). We consequently reviewed the literature and found 35 stud...
Article
Full-text available
Understanding occupants’ satisfaction with their environment is an important step to improve indoor environmental quality (IEQ). These satisfaction data are limited to Singaporean commercial buildings. We surveyed (N = 666) occupant satisfaction with 18 IEQ parameters in seven Green Mark certified air-conditioned commercial buildings in Singapore....
Article
Full-text available
The Center for the Built Environment (CBE) Thermal Comfort Tool is a free online tool for thermal comfort calculations and visualizations that complies with the ASHRAE 55–2017, ISO 7730:2005 and EN 16798–1:2019 Standards. It incorporates the major thermal comfort models, including the Predicted Mean Vote (PMV), Standard Effective Temperature (SET),...
Article
Full-text available
Significant energy savings can be achieved by promoting elevated air speed using ceiling fans by increasing the cooling set-point temperature of an air-conditioning system. However, fan blades that obstruct the light from an artificial ceiling fixture from the relative viewing position of a building occupant could causes problems of visual flicker....
Article
Full-text available
Luminance adjustment is widely used to evaluate discomfort due to glare. This paper reports an experiment conducted to investigate two factors of the luminance adjustment procedure, stimulus range bias and direct vs indirect control. Stimulus range bias describes the influence on subjective evaluations of the range of stimuli available to the test...
Article
Full-text available
The predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) are the most widely used thermal comfort indices. Yet, their performance remains a contested topic. The ASHRAE Global Thermal Comfort Database II, the largest of its kind, was used to evaluate the prediction accuracy of the PMV/PPD model. We focused on: (i) the accuracy of...
Article
Full-text available
Current thermal comfort standards use Predicted Mean Vote (PMV) classes as the compliance criteria despite previous critiques. The implicit assumption is that a narrower PMV range ensures higher thermal acceptability among building occupants. However, our analysis of a global database of thermal comfort field studies demonstrates that PMV classes a...
Article
Full-text available
Replicating scientific findings is a fundamental aspect of research. However, in studies of discomfort due to glare, it is difficult to make comparisons between the results of different experiments since the statistical tests usually reported do not allow independent findings to be directly compared to each other. Here we present an alternative Bay...
Article
Full-text available
Recognizing the value of open-source research databases in advancing the art and science of HVAC, in 2014 the ASHRAE Global Thermal Comfort Database II project was launched under the leadership of University of California at Berkeley's Center for the Built Environment and The University of Sydney's Indoor Environmental Quality (IEQ) Laboratory. The...
Conference Paper
Personal comfort models predict an individual’s thermal comfort instead of the average response for a large population. We attempted to develop personal comfort models for car drivers using data collected from 10 cars while driving for approximately 2,000 hr. We measured conditions collected by the CAN-bus (Controller Area Network), a data acquisit...
Article
Space cooling is a significant energy consumer in office buildings in the subtropical climate zone. An adequate energy policy for indoor spaces should accordingly incorporate both energy conservation and an acceptable level of indoor environmental quality (IEQ). This study investigates the cooling energy consumption for IEQ acceptance in Hong Kong...
Article
Potential bioaerosol infection risk associated with toilet flushing has not been sufficiently addressed in the design of residential washroom exhaust system. This study evaluates the performance of exhaust ventilation for residential washrooms in terms of air change rate, washroom size, washroom geometry, and locations of door louver, exhaust and w...
Article
The residential sector accounts for a significant and increasing portion of the national energy use. Cooling energy reduction in the public housing sector is one of the key success factors for sustainable building development measures especially in the sub-tropics. This study proposes a hybrid EnergyPlus (EP) — artificial neural network (ANN) model...
Conference Paper
This study addresses a concept of the Sustainable Building Environmental Model (SBEM) developed to optimize energy consumption in air conditioning and ventilation (ACV) systems without any deterioration of indoor environmental quality (IEQ). The SBEM incorporates two main components: an adaptive comfort temperature control module (ACT) and a new ca...
Article
Air-conditioned offices in the subtropics are recommended to operate within specified ranges of indoor temperature, relative humidity, air velocity, and carbon dioxide concentration for thermal energy conservation. As environmental discomfort leads to productivity loss, this study investigates the impact of an indoor environmental policy on Grade A...
Article
Minimization of energy loss of water supply networks is a major concern of pump power reduction for sustainable water systems in buildings. This paper presents a mathematical model for energy loss optimization in a common basic T-shaped water supply piping network that serves infinite probabilistic demands. Optimized designs based on proper network...
Article
Energy efficiency in buildings is a key factor for sustainable development. This study examines the electricity consumption in apartments and communal areas for both public and private housing in Hong Kong. A tool based on Monte Carlo sampling has been developed to predict residential electricity consumption in terms of housing type, occupant load...
Article
High-rise housing, a trend in densely populated cities around the world, increases the energy use for water supply and corresponding greenhouse gas emissions. This paper presents an energy efficiency evaluation measure for water supply system designs and a mathematical model for optimizing pumping energy through the arrangement of water tanks in a...
Conference Paper
Minimization of pumping energy is a major concern for designing sustainable water supply in buildings. Modular designs of tree-shaped water supply piping system, such as 2 by N array include water cisterns of water closet in public toilets, washbasin taps in schools are commonly found in building complexes. Potable water demands in water systems se...
Article
This study investigates the relationship between Indoor Environmental Quality (IEQ) and learning performance in air-conditioned university teaching rooms via subjective assessment and objective measurement. Together with the data of air temperature, relative humidity, air speed, mean radiant temperature, CO2 concentration, equivalent sound pressure...
Article
Bus cabin air quality has not been incessantly monitored in Hong Kong. This study investigates the in-cabin exposure levels of CO, CO2 and PM10 for running buses in Hong Kong that are equipped with Euro II, III and IV engines. A representative urban—suburban bus route was chosen and there were no significantly different in-cabin CO levels reported...
Article
Current Building Management System (BMS) does not integrate well with real-time occupant response. A Bayesian control algorithm is presented in this study for fine-tuning the system to meet individual demands and to maximize the occupant acceptance of thermal environment of centralized air-conditioned offices. A weighting function for air temperatu...
Article
This paper reports thermal sensations of residents exposed to their chosen thermal environment and compares with predictions made with the Fangeťs predicted mean vote (PMV) thermal comfort model. In this study, thermal sensation responses of 221 residents at 74 apartments in Hong Kong towards the exposed thermal environment at the resident choices...

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Projects

Projects (3)
Project
Maintain and enhance features of the CBE thermal comfort tool.
Project
The project is my PhD study to develop the empirical bioaerosol drag coefficient model to investigate the transport mechanism of bioaerosol particles (i.e. bacteria, fungi and virus). The major reason is that bioaerosol particles in indoor air are related to airborne transmission infections and some pandemic outbreaks such as Severe Acute Respiratory Syndrome (SARS) in 2003 and Middle East Respiratory Syndrome (MERS) in 2015. Several environmental control strategies and parameters for a ventilation system have been suggested to prevent infections in building environments. To design an appropriate ventilation system, the infection risks of the proposed ventilation system were evaluated in the thesis in order to achieve effective infection control. Computational fluid dynamics (CFD) simulation is often used to predict the dispersions and depositions of bioaerosol particles to evaluate the infection risks of ventilation systems. However, there are differences between bioaerosol and aerosol particles in terms of shape, diameter, surface texture and elasticity. In this study, the transport mechanism of a bioaerosol particle was investigated to formulate a bioaerosol particle transport model for CFD simulation.
Project
The SinBerBEST program, funded by the National Research Foundation (NRF) of Singapore and headed by Professor Costas Spanos, is one of two core research programs within Berkeley Education Alliance for Research in Singapore (BEARS). The Berkeley Education Alliance for Research in Singapore (BEARS) is a center for research, graduate education, and innovation directed by Professor Masayoshi Tomizuka. BEARS was established in 2011 by the University of California, Berkeley as a non-profit company. SinBerBEST is an interdisciplinary group of researchers from UC Berkeley, Nanyang Technological University (NTU), and the National University of Singapore (NUS) who come together to make an impact with broadly applicable research leading to the innovation of energy efficient and sustainable technologies for buildings located in the tropics, as well as for economic development. SinBerBEST's mission statement is as follows: “Advance technologies for designing, modeling and operating buildings for maximum efficiency and sustainability in tropical climates.” http://sinberbest.berkeley.edu/