Indoor thermal environment

Under the influence of biological hazards including COVID-19, it is required sufficient ventilation to decrease the infection risk in the indoor area. In particular, the natural ventilation with window opening is recommended in rooms with inadequate ventilation. However, the ventilation rate, energy loss, and indoor thermal environment with window opening in air-conditioned room varies hourly with given environment. In addition, opening windows in winter causes serious problems such as deterioration of the indoor thermal environment and reduction of absolute humidity.

In typical Chinese commercial kitchens, the large amount of heat and moisture that is generated must be removed. The ventilation and energy consumption rates can be huge. Middle and small scale commercial kitchens in China produce an exhaust airflow rate so large that without a reasonably effective ventilation system, the temperature and contaminant concentrations are far more than acceptable levels. To fulfil all the requirements of indoor air conditioning in an economical manner, a new air distribution pattern called air curtain ventilation (ACV) is presented in this study.

In order to research the indoor thermal conditions and residential thermal comfort in low-pressure plateau climate, a field study was conducted from December 2007 to February 2008 of 20 residential buildings in Lhasa. A total of 44 participants provided 356 sets of physical measurements together with subjective questionnaires that were used to collect the data. By linear regression analysis of responses based on the ASHRAE seven-point thermal sensation scale, the neutral air temperature of the total samples based on thermal sensation was 19.3℃.

Recently, insulation retrofits of existing houses have been thought to be one of the effective measures from the viewpoint of global warming prevention. However, the overall reduction effects of environmental loads by the insulation retrofits have not yet been clarified. This study intends to accumulate basic data concerning the insulation retrofits and to promote the energy saving of existing houses. 

Recently, a lot of multiple packaged unit system is adopted in small to medium sized buildings in Japan. This system enables to control each packaged air conditioner (PAC) individually because multiple packaged units are placed decentrally. However, it is not clarified sufficiently how indoor environment is formed when PAC is working. This paper shows the measurement results of indoor thermal environment in a medium sized building with PAC in all season for the purpose of clarifying the current status of indoor environment and its issue.

Study on existing indoor thermal environment is becoming more and more important for design of theindoor thermal environment and the application of energy-saving technology. In this work the fieldmeasurement of thermal environment in a complex atrium building was conducted and different effectson the indoor thermal environment were analyzed. The atrium is 14m in height. The first floor is forexhibition, and the cooling air can be supplied by air jets located on the upper position of the sidewall.The corridors on the second and third floors are not air conditioned.

This paper presents a study of the impact of urban warming upon energy consumption forair-conditioning in the home, using a numerical simulation model. The results are as follows. 1) In citiesother than Sapporo and Sendai, about 50% of the total hours of occupancy were ventilation hours, andabout 20% to 40% were cooling hours. As a result, the total energy consumption for cooling wascomparatively large. 2) In these other cities, cooling hours increased in the summer as the outdoortemperature rose.

The purpose of this paper is to analyze the indoor thermal environment and ventilation efficiencycreated by various heating and ventilation systems using CFD. In the case of one room, the value ofmean local air exchange efficiency????*1 of breathing zone*2 becomes about 1.0, because fresh airspreads completely in the room when air-conditioners are operated. In contrast, when air-conditionersare not operated, the mean ?? becomes smaller than 1.0, and the area of poor ventilation efficiencybecomes large.

The impacts of indoor thermal environment on body physiology have been carried on for four years (2003-2007) in laboratory in Chongqing, a typical city located in hot-summer and cold-winter region in China. Experimental objectives used are healthy university students. The range of indoor air temperature in summer is 25 C - 37.5 C.The objectives physiological changes (Motor nerve Conduction Velocity, Sensory nerve Conduction Velocity, Skin Temperature etc.) under different temperatures and ventilations have been tested.