The air-conditioned office building design in the tropical hot-and-humid climates has seldomtaken into account adaptation principle to thermal comfort. This induces the occupants to findcomfort at the pre-determined comfort criterion in air-conditioned enclosure and they soondevelop a higher expectation of homogeneity that in turn leads to demand of coolertemperatures. Though the research knowledge is large, practical implementation has aptlyignored the variability of individuals comfort criteria.
This paper presents the performance of a displacement ventilation system in a thermalchamber with tropical subjects. The chamber is served by an Air-Conditioning andMechanical Ventilation (ACMV) system in either Mixing or Displacement Ventilation modes.In the experiments, tropical subjects were surveyed with respect to their thermal sensationsunder different room conditions in either displacement ventilation or mixing ventilation.Objective measurements such as room air temperature, air velocity and relative humidity weremeasured at different heights in the chamber.
A spot cooling system using the convective cooling effect of an air stream is known to beeffective by its smothering intensive hot environment, supplying comfort sense and utilizingenergy efficiently. However, its study on the interaction with human body or product itself isuncommon, showing that the spot cooling system intrinsically contains the possibility ofdraught because of its short emitting distance from the object, low air temperature, high airstream velocity and its direct local contact to human body.
This paper provides a research about rapid methods and simplified tools to assist the projectactors, such as architects, designers and engineers, involved in the building design, in theearliest conception during the preliminary design. We examine the quality criteria of indoorthermal environment in non-residential existing buildings, with failure in the pre-energyconservation. The main objective is how well to predict a mean thermal comfort sensation forworkers under warm conditions over the tropical climate. The occupants could change theiractivity (metabolic rate) and their clothing.
Thermal comfort in office buildings is usually unsatisfactory when ceiling air distribution isemployed, because it is hard to make adjustments to reach specific occupancy needs. On theother hand, underfloor air distribution allows some flexibility for adjustments. In order toevaluate thermal comfort conditions in office environments with underfloor air supply system,a laboratory facility was built at the Universidade de Sao Paulo, Brazil. In this work,quantitative and qualitative results obtained in such facility are discussed.
This paper considers the predictions obtained using a recently developed ventilation parameter (VP) for evaluating the ventilation performance which combines the indices for indoor air quality and thermal comfort. This ventilation parameter is used to analyse the changes in ventilation performance with changes in the position of workstation in a room ventilated using mixing ventilation.
A series of thermal comfort field data (about 1800 observations), collected in Bari (Southern Italy), were implemented according to the ASHRAE RP-884 world database format, thus constituting a local database for the Mediterranean area, which, with exception of Greece, is not represented in this world database. The collected data, mostly already published, were reexamined in the light of the latest international literature on the subject.
This paper shall investigate thermal comfort requirements for university students in the hot-humid region of Bahrain and the hot-dry region of Saudi Arabia. An extensive field survey shall be conducted among university students in an attempt to define optimum comfort requirements. The field surveys shall deal with the following aspects:
Recording climatic variables, which influence thermal sensation, these are; ambient temperature, radiant temperature, relative humidity and air velocity.
The thermal comfort response of Korean college students was investigated in a thermalenvironment chamber both in summer and winter seasons. Eight thermal conditions consistingof four air temperatures (24, 26, 28, 30C) and three relative humidities (40, 60, 80%) wereselected in summer. Eight thermal conditions consisting of five air temperatures (18, 20, 22,24, 26C) and two relative humidities (40, 60%) were chosen in winter. In each test, sevenfemales or seven males were questioned in the chamber for 3 h, where thermal and comfortsensations were surveyed every 15 min.
This study suggests a computer model capable of predicting thermal environment of an atriumand calculating indoor sol-air temperature, which can evaluate the influence of heat loads thatthe atrium space puts on the adjoining rooms. The computer model is based on zonal modelcombined with the solar radiation model using the Monte Carlo method and ray-tracingtechnique. The accuracy of computer model was validated through scale model test and fieldmeasurement. The average relative error of solar radiation model for predicting solar radiationintensity in atrium space was 11.8%.
Login