Task conditioning system is expected to reduce energy consumption in buildings and also toimprove thermal comfort of occupants. In this paper, an isothermal task unit was developed and its impact on subjective feeling was invesigated. Laboratory and field surveys were carried out. The airflow characteristic of the unit and usage of the unit in an actual office are described. Preferred airflow and seating condition of the workers using the unit were observed. Most of the workers preferred the airflow from the unit. Task unit was most effective immediately after a worker took their seat.
A personalized ventilation system combined with a seat is introduced in this paper. This kind ofventilation seat is able to provide occupants with improved air quality, individual control and energysavings. A thermal manikin with an artificial lung was used to investigate several fundamental issues on this novel ventilation system. We tested the performances of the eight different air supply nozzles within the flow rate range from 0.1 l/s to 3.0 l/s. The highest pollutant reduction of inhaled air about 80% is achieved by one nozzle named SCN at the flow rate of 3.0 l/s.
The performance of two personalized ventilation systems combined with mixing or displacement ventilation was studied under different conditions in regard to thermal comfort of seated occupants. The cooling performance of personalized ventilation was found to be independent of room air distribution. Differences between the personalized air terminal devices were identified in terms of
the cooling distribution over the manikins body. The personalized ventilation supplying air from the
In this study the concept of ‘adaptive behaviour’ is extended to look at the effects of personal adjustments and regulator control changes provided in offices. It is evident from experience as described in the adaptive approach, that clothing can play an
In this paper, characteristics of the indoor environment utilizing hybrid ventilation system andtask-ambient air-conditioning system are investigated every hour in a year in various types of office spaces by means of dynamic cooling and heating load analysis and CFD (Computational Fluid Dynamics) simulation.Authors had investigated the characteristics of the indoor environment of a hybrid ventilation system, utilizing natural and mechanical ventilation, with CFD simulation under various conditions of incoming outdoor air [1].
A distribution of contaminants from floor covering, exhaled air and human bioeffluents was examined in a mock-up of a typical two-person office by means of tracer-gases. The distribution was studied with two types of air terminal device for personalized ventilation combined with displacement ventilation. The results show that the type of personalized ventilation and its use affects the distribution of contaminants to a great extent, as does the type and location of contaminant sources.
Air exhaled by occupants may carry infectious agents and be one way of transmitting respiratory diseases in rooms. The exposure of occupants to exhaled air was examined at two different throw heights of underfloor ventilation combined with two types of personalized ventilation by means of full-scale experiments. The concentration of exhaled air from one occupant was measured in air inhaled by another occupant who used or did not use personalized ventilation.
Subjective experiments with a non-isothermal task conditioning system were conducted toinvestigate impacts of the system on thermal comfort and productivity in a climate chamber of Kanto-Gakuin University, Japan. All subjects participated in "default condition test: 26C / 50% RH" at first.Then a half of the same subjects participated in "standard condition test: 26C / 50% RH", and theremainder subjects participated in "task-ambient test: 30C / 50% RH + TAC", just one week later again separately. Thermal, humidity, comfort sensations, and other psychological factors were investigated.
For the application of personalized (PV) in practice, it is important to recognize its performance under realistic conditions as they apply in rooms. In this paper results of both CFD simulations and laboratory measurements are reported regarding the local ventilation effectiveness with personalized ventilation. It was observed that the personalized air influences only a limited microenvironment at the workstation. Then a new model was proposed to evalate the indoor air quality in the entire space with varied distributions of occupants.
In this article a prototype application of an interactive CFD-based computational steering system is presented, connecting a high performance computer (HPC) with a Virtual Reality (VR) environment. During the preliminary investigation of indoor air flow phenomena the user is able to interact on line, e.g. by modifying the geometry of the simulation scenario during the simulation itself. To allow for a comfortable analysis of complex fluid flow configurations a VR system consisting of a stereoscopic projection unit and a wand device is supported.