This paper demonstrates the importance of the combined use of an energy simulation program and a CFD program for an accurate design of two low energy cooling systems : displacement ventilation and a combined chilled ceiling with displacement ventilation.
Most single-family homes in America today are designed with a single-zone climate control system. This is typically an energy inefficient and ineffective method of conditioning a home. Multi-zone climate control systems are considered to provide improved means of conditioning single-family homes. More so is the case with multi-story homes where thermal balance is difficult to achieve between the lower and upper floors using a single-zone system.
The intention of the authors is to find a proper air conditionning system to achieve higher IAQ environment.They consider a new air-conditioning system that uses both a Partition-type Fan-Coil Units system (PFCUs) with a Dedicated Outdoor Air System (DOAS).
A thermal manikin with a simulated lung was placed in an air-conditioned office with fresh air supplied in close proximity to the facial area at flow rates from 0.1 to 2 l/s. CO2 concentration measurements allow to define the fresh air utilization efficiency and the pollutant exposuer reduction efficiency.
Monitoring of temperature and relative humidity was carried out in an air-conditioned office building during the heating season. In addition, occupants filled in health and comfort questionnaire. Without informing the occupants, humidity was reduced in an experimental area compared to the control area. As this reduction was not so great (2% relative humidity), the differences of occupants perception between areas are not significant. A slight reduction of building related symptoms was observed at higher humidity.
The aim of this study is to investigate an optimal air-conditioning adjustment for an indoor space where people come in and out. The authors conducted the experiments by measuring the physiological and psychological responses of subjects who walked outdoors and then entered a chamber. Psychological responses to summer climate were grouped within three categories of: "cool" - "comfortable," "hot" - "uncomfortable," and "cold" - "uncomfortable." These responses are related with subjects perspiration.
The effects of an air conditioning system for office buildings were studied experimentally and computationally. A displacement ventilation system was used as the main air-conditioning system, and a partition with a built-in circular fan was used to deliver the air-conditioned clean air near the floor supplied by the main displacement system to the occupant in the office directly.
This paper proposes a new personal air-conditioning system, which modifies a common partition used in offices to a partition-type fan-coil unit (PFCU) with inlets and outlets on its surfaces. Chilled water is supplied as the cooling energy, and is delivered to the partitions by pipelines incorporated into the structure. Hence, conventional air conditioning systems using ceiling-based air diffusers for open-plan offices may be dispatched into several small individual systems controlled by the occupants.
The purpose of this study is to clarify the usefulness of a displacement ventilation air-conditioning system introduced into a multipurpose hall after CFD simulation and measurement. In the multipurpose hall of Kurume City, a displacement ventilation air-conditioning system equipped with a floor outlet had been adopted. A CFD simulation for the purpose of selecting an air condition system indicated the floor outlet system would be more effective for the design plan of the hall than a ceiling outlet system.
This paper provides a summary of current knowledge about the associations of ventilation types in office buildings with sick building syndrome symptoms. Most studies completed to date indicate that relative to natural ventilation, air conditioning, with or without humidification, was consistently associated with a statistically significant increase in the prevalence of one or more SBS symptoms, by approximately 30% to 200%.
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