Jiayu Li

Jiayu Li
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Jiayu verified their affiliation via an institutional email.
Verified
Jiayu verified their affiliation via an institutional email.
University of California, Berkeley | UCB · Center for the Built Environment

PhD

About

68
Publications
21,382
Reads
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937
Citations
Additional affiliations
October 2016 - January 2017
January 2023 - November 2023
National Environment Agency, Singapore
Position
  • Senior Principal Research Officer
August 2018 - December 2022
University of California, Berkeley
Position
  • PostDoc Position
Education
September 2013 - January 2019
Tianjin University
Field of study
  • HVAC
September 2009 - July 2013
Chongqing University
Field of study
  • HVAC

Publications

Publications (68)
Article
Full-text available
The dynamic behaviors of airflows, which are common in aircraft cabins with mixing ventilations, significantly influence the thermal sensation of passengers and contaminant transmissions. In this paper, to analyze the large-scale dynamic characteristics in aircraft cabins, a series of long-term large-scale particle image velocimetry (PIV) measureme...
Article
Full-text available
We evaluated diurnal trends of size-resolved indoor and outdoor fluorescent biological airborne particles (FBAPs) and their contributions to particulate matter (PM) within 0.5–20 μm. After a ten-week continuous sampling via two identical wideband integrated bioaerosol sensors, we found that both indoor and outdoor diurnal trends of PM were driven b...
Article
Full-text available
In an experimental study set in Singapore’s tropical climate, we evaluated the thermal environmental performance, energy consumption, and thermal comfort of air and radiant cooling systems, operating at an operative and air temperature of 26 °C. 78 participants across five groups answered thermal comfort surveys in a crossover study design. Environ...
Article
Full-text available
The effects of ceiling fans on the transmission of infectious aerosols remain poorly understood, leading to conflicting recommendations. We conducted repeated experiments in a well-controlled chamber with a typical mixing ventilation system at three different ventilation rates with and without ceiling fans. We evaluated airborne infection risks for...
Article
Full-text available
This study compares air pollutant concentrations resulting from cooking with gas or induction cooktops, with or without either of two recirculating range hoods with filters. A meal of pasta, plant-based “meat” sauce and stir-fried broccoli was cooked three times for each cooktop and hood combination in a 158 m3 room. Time-resolved measurements were...
Article
Full-text available
With the adjustment of the energy structure and the rapid development of commercial complex buildings, building energy systems (BES) are playing an increasingly important role. To fully utilize smart building management techniques for coordinating and optimizing energy systems while limiting carbon emissions, this study proposes a smart building en...
Article
Full-text available
The civil aircraft cabin is enclosed and highly occupied, making it susceptible to a decline in indoor environmental quality. The environmental quality of civil aircraft cabins not only depends on objective factors such as temperature, relative humidity, and the presence of air pollutants such as carbon dioxide (CO2), carbon monoxide (CO), ozone (O...
Article
Full-text available
In July 2021, amid occasional COVID-19 community transmission, an outbreak in a seafood wholesale centre propagated secondary clusters in sheltered markets in Singapore. This period offers a unique chance to study COVID-19 transmission risk factors related to environmental features and personal behaviours in markets. Only 40 % of the population was...
Article
Full-text available
High heat loads in industrial buildings potentially form strong natural convective flows. These flows exhibit significant unsteadiness and anisotropy, which can profoundly impact indoor air distribution. To study the flow characteristics of thermal convective flows in large indoor spaces, we built a large-scale test bench with controllable thermal...
Article
Full-text available
The environment inside airliner cabins has attracted increasing attention. Instantaneous airflow, as one of the fundamental parameters of airflow field, affects aspects of the airliner cabin environment such as occupant comfort and airborne disease transmission. This study evaluated the characteristics of instantaneous airflow in airliner cabins wi...
Article
Full-text available
Elevated air movement produced by fans can offset air-conditioning energy requirements by allowing temperature setpoints to be raised without compromising thermal comfort. These advantages are even greater in hot and humid climates that inherently have large and sustained indoor cooling requirements. Few studies have assessed the in-situ benefits o...
Article
Elevated air movement produced by fans can offset air-conditioning energy requirements by allowing temperature setpoints to be raised without compromising thermal comfort. These advantages are even greater in hot and humid climates that inherently have large and sustained indoor cooling requirements. Few studies have assessed the in-situ benefits o...
Article
SARS-CoV-2 has been recognized to be airborne transmissible. With the large number of reported positive cases in the community, home quarantine is recommended for the infectors who are not severely ill. However, the risks of household aerosol transmission associated with the quarantine room operating methods are under-explored. We used tracer gas t...
Article
Full-text available
The airflow structure of enclosure directly affects the spread of COVID-19 and is also closely related to indoor air quality, thermal comfort of personnel, and building energy consumption. Although a large number of studies on the airflow field have been conducted under mixing and displacement ventilation with a single air inlet in rectangular room...
Article
Full-text available
Cooling load calculation can significantly affect the first cost, energy consumption, and performance of air-conditioning systems. Current peak cooling load calculation theories and methods are developed based on all-air systems, which remove the room heat gains through purely convective heat transfer. Studies found that they are not suitable for r...
Article
Full-text available
Epidemiological surveys have shown a significant association between indoor airborne particle exposure and adverse health effects. Duct-type electrostatic precipitators (ESPs) are effective in controlling airborne particles in buildings. Although several studies have examined the initial performance of duct-type ESPs, there are no comprehensive dat...
Article
Full-text available
The SARS-CoV virus spreads in the atmosphere mainly in the form of aerosols. Particle air filters are widely used in indoor heating, ventilation, and air-conditioning (HVAC) systems and filtration equipment to reduce aerosol concentration and improve indoor air quality. Requirements arise to rate filters according to their mass-based filtration eff...
Article
Full-text available
Cooking-emitted pollution is a major health concern in residential buildings. Compared to actively sampled cooking-emitted airborne pollutants with a focus on the intake portion through the respiratory system, the characteristics of splashed cooking particles deposited on surfaces are largely understudied. Using the 3D fluorescent microscopic passi...
Article
A large amount of paint mist diffuses and escapes into the ambient air, forming oversprayed mist during the spraying process, which severely affects the environment in the spray booth and threatens worker health. To control the oversprayed mist and improve healthy work environments, a source control method is proposed: optimize the structure of the...
Article
A comprehensive understanding of the flow characteristics of thermal plumes during cooking is an essential prerequisite for designing high-performance cooker hoods. A cooking-related thermal plume under the confinement effect of a wall-mounted range hood in a real-sized kitchen is investigated utilizing particle image velocimetry. The experiment wa...
Article
Full-text available
The human body emits a wide range of chemicals, including CO2 and isoprene. To examine the impact of cognitive tasks on human emission rates of CO2 and isoprene, we conducted an across-subject, counterbalanced study in a controlled chamber involving 16 adults. The chamber replicated an office environment. In groups of four, participants engaged in...
Preprint
Full-text available
An aircraft cabin environment is affected by many factors during flights. To investigate the impact of passenger behavior on indoor air quality, three passenger behaviors, adjusting the seatback, turns on the gasper and exhale, were studied separately. An aircraft cabin mockup was used to obtain experimental measurements. The air velocity and conta...
Article
Full-text available
On the 7th of April, the Singaporean government enforced strict lockdown measures with the aim of reducing the transmission chain of the coronavirus disease 2019. This had a significant impact on the movement of people within the country. Our study aims to quantify the impact that these measures had on outdoor air pollution levels. We obtained air...
Article
Full-text available
The purpose of this study was to investigate the influence of large-scale circulation on the flow field in a cabin mockup. The velocity was measured by ultrasonic anemometers (UA). Then, this study analyzed the turbulence kinetic energy spectra of the velocity fluctuation signal. The turbulence kinetic energy spectra of the measurement points refle...
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
Particles generated by cooking are an important source of indoor pollutants. Most studies have focused on only airborne particles rather than including a wide range of particle sources, such as the large oil droplets generated by splashing during cooking, which constitute most of the mass concentration of indoor pollutants. In this study, the fluor...
Article
Full-text available
This study evaluated the interrelations between indoor and outdoor bioaerosols in a bedroom under a living condition. Two wideband integrated bioaerosol sensors were utilized to measure indoor and outdoor particulate matter (PM) and fluorescent biological airborne particles (FBAPs), which were within a size range of 0.5‐20 μm. Throughout this one‐m...
Article
Full-text available
In small occupied spaces such as vehicle cabins, in-depth information about human thermal plumes can be important for designing ventilation systems, especially in the case of displacement ventilation. In this study, large-scale time-resolved particle image velocimetry measurements were performed to reveal airflow characteristics of thermal plumes i...
Article
As people are increasingly traveling by air, the aircraft cabin environment has received considerable attention in recent years. Temperature, CO2, and noise can influence the cabin environment, but their relative importance is unknown. This paper combined data from an objective mental performance test and a subjective questionnaire survey to obtain...
Article
The human thermal plume induced by body heat loss has a significantly impact on human thermal comfort , contaminant transport and indoor air quality. Few studies focused on the temporal unsteady characteristics of human thermal plume. In this study, the human thermal plume generated by a heated manikin was measured in a 7-row cabin mockup by mini p...
Conference Paper
Full-text available
The thermal plume generated by human heat loss has a significant impact on human thermal comfort, contaminant transport and indoor air quality. Few studies have concerned the unsteady characteristics of human thermal plume which has significant impact on human health and comfort. Therefore, the human thermal plume was measured by min-PIV in a 7-row...
Article
Full-text available
The role that thermal plumes play becomes more crucial, especially in a densely occupied space, such as an aircraft cabin. In this paper, the aim is to isolate this effect and to investigate the air distribution of individual human thermal plumes in the cabin. For this purpose, the thermal plume conditions in the aircraft cabin have been developed...
Article
The turbulence characteristics of instantaneous airflows in an aircraft cabin mockup are measured by high-frequency mini particle image velocimetry (mini-PIV) and analyzed by higher-order turbulent statistics. Under maxing ventilation in the aircraft cabin, two jets from the diffusers collide each other in the middle of the aisle. The airflows of c...
Article
Full-text available
The window purifying ventilator is a relatively new idea that involves replacing one part of the window frame with a ventilator, for which the core component is a cross-flow fan (CFF). When a CFF is applied to the window purifying ventilator, a filter should be added, and its casing should be modified. In this paper, first, time-accurate solutions...
Article
Full-text available
The flow field is actually the result of natural convection and forced convection interaction inside the cabin with narrow interior space and passengers seated intensively. To study the effect of the natural convection on the airflow field inside occupied cabins, a full-scale 7-rows cabin mockup of Boeing737-200 has been researched with a two-dimen...
Article
Full-text available
In recent IAQ studies, there is much concern about air quality in school buildings. This paper focuses on indoor air quality in classrooms of two primary schools in Beijing, China. Ventilation rates, CO2 and PM2.5 are measured and analyzed. The results show that ventilation rates in naturally ventilated classrooms with windows and doors closed are...
Article
Many previous studies have mentioned the critical effect of natural convection caused by passengers heat transfer on the air distribution inside the air cabins, but No study focused on it to make a further experimental or numerical analysis. In fact, the air flow field inside the air cabin with narrow interior space and passengers seated intensivel...
Article
Full-text available
Mixing air ventilation systems are currently used in commercial airplane environmental control systems (ECS), which are essential to create a safe, healthy and thermally comfortable cabin environment. To evaluate the performance of cabin air distributions, the first step is to quantify how the airflow gets distributed within cabins. In this investi...

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