The air quality in laboratories has a profound affect on occupant health and safety. Reducing the timeof exposure and the amount of contaminant can improve the occupant environment and have directimpact on health and safety. In this study, a novel ventilation system which introduces benchexhausts is proposed. The system offers the potential for application in new and existing researchlaboratories to effectively remove airborne contaminants at the bench using a technology that is costeffective and efficient.
The requirements for thermostats are increasing in the U.S. for a combination of reasons. Firstly,energy conservation and Demand Response programs are requiring thermostats to have morecomplex controls that can communicate with electric utilities. Other pressures are caused by theincreasing sophistication in U.S. homes such as systems for mechanical ventilation, economizers andventilation cooling that interact with operation of heating and cooling systems via thermostat controls.In order to meet these challenges, U.S.
The objective of this paper is to present the contaminant removal efficiency of a prototype air cleanerusing the adsorption/desorption effect and to investigate the practicality of this air cleaner. Toluene andformaldehyde were used as pollutant sources and were emitted at a constant rate in a test chamber.Effects of the number of sorption units, the operational time and mode on the contaminant removalperformance were examined. Sorption materials that were evaluated were a porous material, zeolite,pumice stone, and hydro-corn.
The summer natural wind environments inside an airport terminal building under two cases aresimulated by the method of computational fluid dynamics (CFD) in this paper. The two cases havedifferent opening areas for glass curtain wall. Case 1 has the opening ratio of 10% while Case 2 has30%. The paper also uses DeST to simulate the annual natural temperature distribution under twokinds of opening ratio in a whole year.
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.