English

The purpose of this study was to clarify differences between evaluations of thermal environment undercross ventilation and airflows from air-conditioning systems and electric fans. Nine subjects evaluatedthermal sensation, thermal comfort sensation, airflow sensation and humidity sensation in anexperimental room in the summer of 2006. The surrounding ambient temperatures, relative humidity,and air velocity were measured simultaneously.

Convective heat transfer coefficient on the air side of direct expansion evaporator under low airpressure is studied by theory and experiment respectively. Results show the convective heat transfercoefficient will diminish along with the density of air under low-pressure. The lower absolute humidity ofair under lower pressure will reduce the difference of water vapor pressure between the air supply andair return. And the quantity of latent heat transfer between the evaporator and the air will decreaseaccordingly.

The outside convective heat transfer coefficient (CHTC) of building roof is an important parameter foraccurately calculating heat transfer through roof and simulating airflow around buildings. However, thecorrelations concerning CHTC in various studies seem to be discrepant. The experiment usingnaphthalene method to measuring CHTC was carried out on a nine-story building roof during 15 August2006-22 August 2006. Test specimens with glazed surface were ranged at twenty points on buildingroof. Test specimens used in this study were cast by molten naphthalene in molds.

With the change of the economic structure, most of the old industrial buildings built before 1972 inHong Kong are now used as offices or non-industrial workplaces. Those old building might not haveadequate fire safety provisions and it is difficult to upgrade these hardware provisions too. Theoccupational safety and health problems on fire safety are even more serious if the offices are use forsmall and medium enterprises which have special characteristics of small areas packed with largequantity of combustibles and high occupant loading.

A numerical simulation study on natural ventilation of two connected chambers in connection with anambient environment is presented in the paper. Extending a model of single-room displacementventilation, this study addresses a space consisting of two chambers connected by one opening at thelow level of the shared wall. A thermal load is placed only in one chamber, referred as a forced chamber,and the other chamber, unforced chamber, has no heat load. The space is connected to the outsideambient environment to have displacement ventilation in both chambers.

Chinese kang, an ancient home heating system, is an integrated system for cooking, sleeping,domestic heating and ventilation. It is estimated that in 2004 there were all together 66.85 millionChinese kangs used by 43.64 million rural families and 174 million people. Chinese kang is potentiallyan energy-saving heating system, which uses high thermal mass to store surplus heat from stoveduring cooking and releases it during the rest time for home and bed heating. Such a widely used ruraldomestic heating system is rarely mentioned in the open research literature.

Malaysia is situated near the equator of earth where the weather is hot and humid. The vulnerableenvironment has induced many Indoor Air Quality (IAQ) concerns in hospitals by health professions inmany countries. There is mounting evidence on IAQ exposure leading to excessive morbidity andmortality. Many extensive studies have been conducted but there is not many IAQ standard to-date.The objective of the study is to present the finding of the source of indoor air quality in a new hospital inMalaysia. The study also presents the solution to overcome the IAQ problem faced by the hospital.

This study evaluated and optimized the thermal environment inside an air-conditioned train stationbuilding using the computational fluid dynamics (CFD) method. The impacts of some air-conditioningdesign parameters such as supply air temperature, velocity, altitude and incidence angle on indoorthermal environment were discussed. The primary air-conditioning design scheme was optimized.

The heat and mass transfer mode of the plate-fin enthalpy exchanger is simplified as the cross-flowheat exchanger in which the fluids of two sides do not mix up. Based on the analogical principle of heatand mass transfer, the relationship of? ? NTU is computed and plotted by the numerical calculation.Compared this relationship with experimental result, it can be drawn that this relationship is accurate tomeet the requirement of engineering. According to the result of numerical calculation and experiment,air face rate has more influence on sensible efficiency than latent efficiency.

As two common kinds of air supply modes, natural wind and mechanical wind have obvious differenceson human sensation. From former researches, it can be seen that the 1/f fluctuation property of thespectrum of natural wind is an important factor to cause people feel more comfortable.