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When nuclear power plants are under accident conditions, normal air-conditioning system will cease for safety considerations. However, the equipment still generates much heat and indoor temperature will rise rapidly, which threatens the personnel safety. Therefore, massive concrete envelopes with cooling fins are expected to absorb the heat passively from the indoor air continuously. The numerical simulations were conducted to study the temperature change and distribution during a 72-hour period. The results show that indoor temperature was 298.37 K at the final hour, with the maximal increase of 6.34 K in the beginning. The massive envelopes with cooling fins can be a reliable and effective way to mitigate the temperature rise under accident conditions. [ABSTRACT FROM AUTHOR]

Taking the capillary ceiling radiation air conditioning system in radiation cooling Laboratory of comprehensive experimental building in Shandong Jianzhu University as an example, research the two different control methods which are room temperature control and water temperature control. The roof cooling model was established by using TRNSYS simulation software, two typical summer days were selected to explore the stability of the room temperature and the supply and return water temperature, research the comfort of human body and system energy consumption under two control methods. The results show that the indoor temperature of the two control methods can be stable at the design temperature of 27℃ under outdoor high temperature environment in summer. When the maximum outdoor temperature does not exceed 30℃, the temperature stability of the room temperature control method is better, the comfort of the two control methods can meet the requirements, but the water temperature control method is more comfortable. The room temperature control method is 20% ~ 25% energy saving than the water temperature control method in the two typical selected days, and is 40.5% energy saving in the whole cooling season. [ABSTRACT FROM AUTHOR]

The degree of jet entrainment is affected by the exit conditions and thus affect the air terminal device design. While investigations of jet exit conditions have been carried out by experiments and simulations, it can be considerable advanced by the theoretical analysis. Effect of velocity profile and turbulence intensity at jet exit on jet entrainment are examined based on the field synergy theory by calculating the mass transfer field synergy number, that is the synergy between the velocity vectors and the species concentration gradients for a given jet flow rate. It showed that the entrainment increases with the increase of the mass transfer field synergy number, and vice versa. The mass transfer field synergy number can be changed by the boundary conditions to strengthen or weaken the convective mass transfer of jet entrainment. This work has resulted in a better understanding of the convective mass transfer phenomenon of jet entrainment and give a guide for air terminal device design. [ABSTRACT FROM AUTHOR]

A thorough assessment is critical for understating and enhancing building energy performance. This paper presents a three-level energy performance assessment method for information-poor buildings where very limited energy use data are available. Using this method, the energy performance of a building can be assessed at multiple levels (i.e., building level, system level and component level ) based on limited energy use data and few in-situ measurement and/or catalogue data of air-conditioning systems. The core part of this assessment method is a quantitative energy performance calculation method that consists of two basic energy balances, simplified models of air-conditioning components and an optimization algorithm based on the energy balances within buildings. The proposed assessment method is well validated in a high-rise building in Hong Kong by comparing the energy performance data from the proposed method with that from detailed measurements. Results show that this method can estimate the energy performance indicators quantitatively at three levels with acceptable accuracy. [ABSTRACT FROM AUTHOR]

Using wireless sensor networks to collect indoor temperature and humidity data, a monitoring system is built. According to the data of the central processing unit, the state of the current room is analyzed, and the cooling capacity (heat) and air volume of the central air conditioner are calculated. Meanwhile, this system calculates the relevant fees based on the amount of cold (heat) consumed by each user, and provides a more accurate data base for the central air conditioning system for energy efficiency optimization. The results show that this system can accurately reflect the environmental status of the target room. Therefore, it is concluded that the indoor environment monitoring system based on wireless sensor network and embedded technology proposed in this paper is effective and feasible. [ABSTRACT FROM AUTHOR]

Extensive studies have been done on adaptive thermal comfort for naturally ventilated buildings. However, further studies of the adaptive comfort model are needed to develop a control method for buildings with the air-conditioning systems. This study aims to extend the application of the adaptive comfort model by developing an adaptive comfort control (ACC) for air-conditioning systems. Special attention is given to testing the acceptability of the ACC to the occupants of the office buildings. Two extensive longitudinal field studies were carried out that involved 807 office workers and a total of 13,523 individual comfort votes were collected. This study reveals that it is possible to develop statistically and substantively significant adaptive comfort models for the cooling operation of air-conditioned buildings. This field study provides scientific evidence that the adaptive comfort model can be used to control an air-conditioning system without sacrificing occupants’ thermal comfort. Further field studies on air-conditioned buildings are warranted to quantify the energy use implications of the ACC. [ABSTRACT FROM AUTHOR]

Abstract: It requires more energy to maintain a narrow indoor temperature range than a broader range, in which the building may be allowed to float with reduced conditioning for longer periods of time. A narrow range should presumably be preferable to the building occupants to justify its increased energy cost. At what widths are temperature ranges detected, preferred, or judged unacceptable? Three databases of occupant satisfaction in buildings are used to examine the acceptability of three classes of temperature range currently employed in the ISO and European standards, and proposed for the ASHRAE standard. These are alternatively identified as class A, B, and C, or category I, II, and III, but their specifications are identical. The A class (I category) is found to confer no relative satisfaction benefit to individuals or to realistic building occupancies. In addition, the differences in B and C class satisfaction are small. [Copyright &y& Elsevier]

Abstract: This study has focused on the evaluation of the optimal temperature in each cabin of the Korean maritime patrol vessels. We aptly modified the inland indoor items and criteria of clothing and activities, and then investigated the human factors in the cabins of Korean maritime patrol vessels. The total thermal resistance of clothing in the wheelhouse was 0.097, 0.079, 0.096, and 0.130m2 °C/W and that for the accommodation areas was 0.067, 0.059, 0.084, and 0.101m2 °C/W in spring, summer, fall, and winter, respectively. The metabolic rate was 228.04W/m2 in the training room and above 100W/m2 in the engine room and auxiliary machine room. In the wheelhouse and accommodation, the metabolic rate was 78.14 and 44.45W/m2, respectively. Based on human factors, the optimum temperature was 23°C in the wheelhouse and 29°C in the accommodation. Therefore, 6°C of energy can be saved in case of PMV/PPD-based air conditioning. [Copyright &y& Elsevier]