Human Perception Relation between Thermal Comfort and Air Movement for Ceiling Mounted Personalized Ventilation System

2014 ◽  
Vol 935 ◽  
pp. 329-332
Author(s):  
Bin Yang ◽  
Chandra Sekhar
Keyword(s):  
Thermal Comfort ◽  
Ventilation System ◽  
Human Perception ◽  
Office Work ◽  
Pv System ◽  
Movement Perception ◽  
Ambient Temperatures ◽  
Air Movement ◽  
Air Temperatures ◽  
Personalized Ventilation

As one kind of newly developed personalized ventilation (PV) system, the relation was explored between thermal comfort and air movement perception/acceptability/preference with tropical subjects, who had become passively acclimatized to hot conditions in the course of their day-to-day life. The tests were conducted in field environmental chamber (FEC) of National University of Singapore. 32 subjects (16 males and 16 females), performed normal office work, can choose to expose to four different PV airflow rates (4, 8, 12, 16 L/s) so as to simulating individual control. Ambient temperatures of 26°C and 23.5 °C and PV air temperatures of 26 °C, 23.5 °C and 21 °C were utilized to conduct parametric variation studies. Each combination was maintained for 15 minutes during which the subjects responded to computer-administered questionnaires. Under different PV airflow rates and ambient/PV temperature combinations, the relation between thermal comfort and air movement perception/acceptability/preference was analyzed.

Influence of sinusoidal airflow and airflow distance on human thermal response to a personalized ventilation system

2016 ◽  
Vol 27 (3) ◽  
pp. 317-330 ◽  
Author(s):  
Yongxin Xie ◽  
Sauchung Fu ◽  
Chili Wu ◽  
Christopher Y.H. Chao
Keyword(s):  
Thermal Comfort ◽  
Thermal Sensation ◽  
Human Subjects ◽  
Ventilation System ◽  
Thermal Response ◽  
Joint Effect ◽  
Experimental Conditions ◽  
Movement Perception ◽  
Air Movement ◽  
Personalized Ventilation

Since the concept of personalized ventilation was introduced in the late 1990s, many studies on thermal comfort have been conducted and a number of parameters identified. In this research, the influence of three parameters, the airflow speed, airflow fluctuating period and a parameter which has drawn less attention in previous studies – the airflow distance between the human subject and the nozzle of the personalized ventilation device on air movement perception, thermal sensation and thermal comfort – are studied. The combinations of fluctuating period and airflow amplitude were selected based on the Power Spectrum Density method. Then 25 human subjects participated in the thermal comfort experiment, each of them underwent 54 tests of different experimental conditions and expressed their thermal feelings by completing the survey questionnaire. Our findings showed that a longer airflow distance could lead to cooler thermal sensation, but not cause any difference in thermal comfort. Changing the fluctuating period of the sinusoidal airflow from 10 s to 60 s did not cause an influence on thermal sensation, but a shorter fluctuating period could result in a higher air movement perception. When dealing with thermal comfort issues, a joint effect with airflow speed and fluctuating period occurs and this should also be considered.

scholarly journals Operation Testing of an Advanced Personalized Ventilation System

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1596 ◽  
Author(s):  
Csáky ◽  
Kalmár ◽  
Kalmár
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Distribution System ◽  
Noise Level ◽  
Background Noise ◽  
Ventilation System ◽  
Air Distribution ◽  
Personalized Ventilation

Using personalized ventilation systems in office buildings, important energy saving might be obtained, which may improve the indoor air quality and thermal comfort sensation of occupants at the same time. In this paper, the operation testing results of an advanced personalized ventilation system are presented. Eleven different air terminal devices were analyzed. Based on the obtained air velocities and turbulence intensities, one was chosen to perform thermal comfort experiments with subjects. It was shown that, in the case of elevated indoor temperatures, the thermal comfort sensation can be improved considerably. A series of measurements were carried out in order to determine the background noise level and the noise generated by the personalized ventilation system. It was shown that further developments of the air distribution system are needed.

scholarly journals Sistema de Ventilação Personalizada Instalado na Poltrona em Cabine de Aeronave: Análise da Concentração e da Eficiência na Remoção de Partículas Expiratórias

REVISTA PLURI ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 77
Author(s):  
Victor Barbosa Felix ◽  
Douglas Fabichack Jr. ◽  
Paulo Rogério Celline ◽  
Arlindo Tribess
Keyword(s):  
Air Quality ◽  
Removal Efficiency ◽  
Experimental Analysis ◽  
Ventilation System ◽  
Particle Removal ◽  
Pv System ◽  
Aircraft Cabins ◽  
Personalized Ventilation ◽  
Mode Of Transport ◽  
Ventilation Systems

As pessoas viajam cada vez mais de avião e, muitas vezes, estas viagens são longas. A qualidade do ar dentro desse meio de transporte torna-se então uma questão crucial, principalmente agora que o mundo está passando por uma pandemia causada pela COVID 19. Uma forma de melhorar a qualidade do ar e as condições de conforto térmico dentro de uma cabine de aeronave está na utilização de novos sistemas de ventilação personalizada. No presente trabalho é apresentada análise experimental da influência de um sistema de ventilação personalizada (PV) na concentração e na eficiência de remoção de partículas expiratórias em cabine de aeronave com sistema de ventilação convencional por mistura (MV). Os ensaios foram realizados em um mock-up com 12 lugares, com três fileiras de quatro poltronas. Medições de concentração de partículas foram realizadas na região de respiração, a 1,10m do piso, em todos os assentos da cabine. Os resultados mostram que a eficiência na remoção de partículas na região de respiração, considerando toda a cabine, é de até 25% para partículas de 5 a 10 μm e de até 30% para partículas de 2 a 5μm. Os resultados mostram também que a eficiência na remoção de partículas é praticamente igual para o sistema PV operando tanto no assento da janela quanto no assento do corredor para todos os tamanhos de partículas. Os resultados da eficiência de remoção de partículas mostram que o sistema PV influencia significativamente a remoção de partículas no assento no qual o sistema está operando e na cabine como um todo.Palavras-chave: Sistemas de Ventilação, Qualidade do Ar, Partículas Expiratórias, Análise Experimental, Cabines de AeronavesAbstractPeople travel more and more by plane, and often these trips are long. Air quality within this mode of transport then becomes a crucial issue, especially now that the world is experiencing a pandemic caused by COVID 19. A way to improve air quality and thermal comfort conditions inside a cabin of aircraft is in the use of new personalized ventilation systems. This work presents an experimental analysis of the influence of a personalized ventilation system (PV) on the concentration and efficiency of removal of expiratory particles in an aircraft cabin with a conventional mixing ventilation system (MV). The tests were carried out in a mock-up with 12 seats, three rows with four abreast. Measurements of particle concentration were performed in the breathing region, 1.10 m from the floor, in all seats of the cabin. The results show that the efficiency in removing particles in the breathing region, considering the entire cabin, is up to 25% for particles of 5 to 10 μm and up to 30% for particles of 2 to 5 μm. The results also show that particle removal efficiency is practically the same for the PV system operating on both the window seat and the aisle seat for all particle sizes. The results of particle removal efficiency show that the PV system significantly influences the removal of particles in the seat on which the system is perating and in the cab as a whole.Keyworks: Ventilation systems, Air Quality, Expiratory droplets, Experimental analysis, Aircraft cabins

scholarly journals The Determination of Indoor Air Quality and Thermal Comfort with Different Space and Ventilation in the Teracce and Bungalow Houses

2021 ◽  
Vol 16 (3) ◽  
pp. 774-793
Author(s):  
Nur Baitul Izati Rasli ◽  
Nor Azam Ramli ◽  
Mohd Rodzi Ismail
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Physical Parameters ◽  
Air Contaminants ◽  
Code Of Practice ◽  
Air Movement

This study observed the influence of different ventilation, indoor and outdoor activities (i.e., cooking, praying, sweeping, gathering, and exhaust from motorcycle) between a bungalow house (i.e., stack and cross ventilation applications) and a terrace house (i.e., one-sided ventilation application). We appraised the indoor air quality (IAQ) and thermal comfort. We monitored the indoor air contaminants (i.e., TVOC, CO, CH2O, PM10, O3, and CO2) and specific physical parameters (i.e., T, RH, and AS) for four days in the morning (i.e., 6.00 a.m. – 9.00 a.m.), morning-evening (i.e., 11.00 a.m. – 2.00 p.m.), and evening-night (i.e., 5.00 p.m. – 8.00 p.m.) sessions. The results found that cooking activities are the major activities that contributed to the increase of the TVOC, CO, PM10, O3, and CO2 concentrations in the bungalow and terrace houses. However, IAQ exceeded the Industry Code of Practice on IAQ (ICOP) limit in the terrace house. The bungalow house applies stack and cross ventilation, double area, and a long pathway of indoor air contaminants movements. Besides that, the results indicated that cooking activities worsen the ventilation system because CO2 exceeded the ICOP limit on Day 2 at 74.1 % (evening-night session) and Day 3 at 13.2 % (morning session), 11% (morning-evening session), and 50.1 % (evening-night session). Moreover, the combination of mechanical (i.e., opened all fans) and natural ventilation (i.e., opened all doors, windows, and fans) is the best application in the house without a cooking ventilator with lower indoor air movement. Furthermore, the temperatures exceeding the ICOP limit of 23-26 °C for both bungalow and terrace houses could be lower indoor air movement, which is less than the ICOP limit of 0.15-0.5 m/s and high outdoor air temperature. Therefore, it is prudent to have an efficient ventilation system for acceptable indoor air quality and thermal comfort in the family house.

Effective Mixed-Mode Ventilation System With Intermittent Personalized Ventilation for Improving Thermal Comfort in an Office Space

2020 ◽  
Author(s):  
Elvire Katramiz ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Thermal Comfort ◽  
Control Strategy ◽  
Mixed Mode ◽  
Natural Ventilation ◽  
Energy Savings ◽  
Ventilation System ◽  
Energy Performance ◽  
Building Performance Simulation ◽  
Office Space ◽  
Personalized Ventilation

Abstract The mixed-mode ventilation (MMV) system is an energy-friendly ventilation technique that combines natural ventilation (NV) with mechanical air conditioning (AC). It draws in fresh air when the outdoor conditions are favorable or activates otherwise the AC system during occupancy hours. To improve performance of the MMV system, it is proposed to integrate it with an intermittent personalized ventilation (IPV) system. IPV delivers cool clean air intermittently to the occupant and enhances occupant thermal comfort. With the proper ventilation control strategy, IPV can aid MMV by increasing NV mode operational hours, and improve the energy performance of the AC system by relaxing the required macroclimate set point temperature. The aim of this work is to study the IPV+MMV system performance for an office space application in terms of thermal comfort and energy savings through the implementation of an appropriate control strategy. A validated computational fluid dynamics (CFD) model of an office space equipped with IPV is used to assess the thermal fields in the vicinity of an occupant. It is then coupled with a transient bio-heat and comfort models to find the overall thermal comfort levels. Subsequently, a building-performance simulation study is performed using Integrated Environmental Solutions-Virtual Environment (IES-VE) for an office in Beirut, Lebanon for the typical summer month of July. An energy analysis is conducted to predict the savings of the suggested design in comparison to the conventional AC system. Results showed that the use of IPV units and MMV significantly reduced the number of AC operation hours while providing thermal comfort.

Investigating Thermal Performance of PCM Plates for Free Cooling Applications in South Africa

2017 ◽  
Author(s):  
Daniel M. Madyira ◽  
Ranwedzi P. Mukhodobwane ◽  
Tien C. Jen
Keyword(s):  
South Africa ◽  
Thermal Comfort ◽  
Ambient Air ◽  
Heat Transfer Fluid ◽  
Air Flow Rate ◽  
Storage Medium ◽  
Ambient Temperatures ◽  
Air Temperatures ◽  
Free Cooling ◽  
Change Material

Free cooling involves using a thermal energy storage medium such as a phase change material (PCM) in order to store the ambient “cold” during the night when ambient air temperatures are lower compared to the indoor building temperatures and release this stored “cold” by using a heat transfer fluid (i.e. air) into the building during the day when higher ambient temperatures are experienced especially during the summer months. This paper assesses the free cooling potential in South Africa by using a set of Rubitherm RT25HC PCM plates. The performance of these PCM plates is assessed by benchmarking the ambient air cooled by the PCM plates during the day against the defined thermal comfort temperatures requirements. The influence of varying the air flow rate on the availability of thermal comfort temperatures at the PCM rig outlet is also studied. The results clearly show the potential of using PCM’s as a means of cooling higher ambient air temperature which is experienced in hot summer months to within thermal comfort temperatures for human occupancy in a building.

scholarly journals Experimental investigation of occupants’ thermal sensation under a personalized ventilation system

2021 ◽  
Vol 2069 (1) ◽  
pp. 012167
Author(s):  
P Ebrahimi Naghani ◽  
S A Zolfaghari ◽  
M Maerefat ◽  
J Toftum ◽  
S M Hooshmand ◽  
...  
Keyword(s):  
Air Temperature ◽  
Cooling System ◽  
Thermal Sensation ◽  
Ventilation System ◽  
Body Part ◽  
Whole Body ◽  
Energy Costs ◽  
Air Temperatures ◽  
The Common ◽  
Personalized Ventilation

Abstract By considering the importance of providing proper indoor environment conditions for occupants and also due to energy costs, one of the solutions for indoor local air-conditioning is Personalized Ventilation System (PVS). In this paper, the occupants’ thermal sensation was experimentally studied for body segments that are mostly affected by the PVS. The local sensation of head, chest, arm, and hand at two supply air temperatures of 16 and 32°C were investigated. Eight volunteer subjects participated in this survey. The subjects reported the most thermal satisfaction on their hands. Also, the arms were the segments with the coolest thermal sensation (-1.28, between slightly cool and cold). Results indicate that the head’s thermal sensation at both supply air temperatures was neutral and the hand was the only body part that experienced warm thermal sensation during the test. Also, by increasing the supply air temperature to 32°C whole body thermal sensation changed from -0.46 to -0.09 on the seven-point scale, which means that the cooling system worked properly for occupants’ cooling. In this system, cooling occurred at 32°C instead of the common 16°C supply air temperature, which results in energy-saving and decreases annual running costs.

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