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To a hospital ward, the temperature and humidity independent control system (THICACS) is very suitable to be applied. However, because of its expensive initial investment, the application of this kind of air-conditioning system is still limited. Based on the conventional THICACS, this paper adopt personalized ventilation and radiation in a triple ward to improve the performance of HVAC system. By simulating the distributions of several key parameters such as temperature and PMV, comparisons and validations are made between conventional and personalized THICACS. The result shows that the amount of the radiant panels are reduced almost 33.8% in personalized ventilation and radiation system. We can draw a conclusion that, by implementing the personalized ventilation to fresh air and the individualized radiation to terminal devices, we can reduce the laying area of the radiant panel and improve indoor comfort levels, which shows a great significance in advancing economics and energy-saving performance of THICACS. [ABSTRACT FROM AUTHOR]

A bed-based TAC system applied to sleeping environments has been developed and its performances experimentally and numerically studied, and the study results are reported in this paper. Firstly, a detailed description of an experimental rig for the bed-based TAC system at two settings is presented with a return air inlet on the wall (Setting 1) and with a return air plenum and inlet placed under the bed (Setting 2). Secondly, the experimental results on the operating performances of the bed-based TAC system at the two settings in terms of thermal environmental control and energy saving are analyzed and reported. Thirdly, to supplement the experimental study for a more detailed analysis on air temperature and flow fields, a follow-up numerical study was carried out and is reported. Both the experimental and numerical study results suggested that the bed-based TAC system at Setting 2 performed better in controlling thermal environment in an occupied zone but with a relatively poorer energy saving performance, as compared to that at Setting 1. [ABSTRACT FROM AUTHOR]

Abstract: Earlier studies used field testing of swimming pool temperatures to validate a mathematical model for predicting the temperature of an unheated pool. Combining those results with manufacturers’ data on the performance of vapor-compression air conditioners as a function of heat rejection temperature, the analyses in the paper suggest that rejecting air conditioning heat to a swimming pool can save approximately 25–30% of single-family residential cooling electricity use and reduce cooling electricity demand during peak conditions by 30–35%, as compared to using the same compressor to reject the heat to ambient air. The savings is expected to vary depending on the severity of the climate, as well as the pool temperature experienced during the summer. The original model was refined so as to accommodate air-conditioner heat rejection to predict pool temperatures based on weather data, pool size, shading of the pool, and air-conditioner heat rejection to the pool. The results of an experimental validation of the augmented pool thermal model are presented here. In addition, the model of a pool-coupled air conditioning system was used to develop a design tool for determining the pool size needed to absorb realistic heat rejection from air conditioners in various California climate zones. [Copyright &y& Elsevier]

Abstract: Following the Japanese Cool Biz campaign which advocated relaxed dress codes and cooling set-points of 28°C in air-conditioned public buildings, other countries have introduced similar policies, with temperature limits varying in different countries. In the UK the British Council for Offices suggested that the summer cooling set-points of UK air-conditioned offices should be increased by 2°C from the previously recommended 22±2°C. However, these recommendations are largely supported by desk-based analysis rather than using field studies. This paper presents the findings of a blind, controlled intervention study conducted in the summer of 2010 in an office building in London to investigate the effects of increasing the current cooling set-point to 24°C. The temperature of one floor was changed and compared with a ‘control’ floor where the set-point remained unchanged. The indoor air temperatures were measured at various locations across the floors to monitor the temperatures the occupants were experiencing. The BUS post-occupancy evaluation survey was used to assess occupants’ self-reported comfort and satisfaction, whilst the NEP questionnaire was used to estimate occupants’ environmental attitudes. The findings from statistical analyses of the data collected for all 129 participants suggest that increasing the set-point temperature led to the occupants feeling significantly warmer in comparison with the group at lower temperature settings. Nevertheless, this did not affect the self-reported thermal comfort of the occupants in the intervention group, as depicted by an insignificant difference between the two groups. It was also observed that there is a positive correlation between the occupants’ tolerance of higher indoor air temperatures and their environmental attitudes, indicating that this could play a key role in the acceptance of indoor temperature changes in the UK. [Copyright &y& Elsevier]

Abstract: In Hong Kong, conventional air-conditioning (AC) systems cause a high energy consumption and poor indoor thermal comfort. This paper investigated the AC load profiles of three typical local commercial buildings, i.e. office, hotel and retail, and examined the energy consumption of liquid desiccant cooling system (LDCS) for these buildings. Simulation results showed that the cooling load contributed to more than 98% of total annual load, with high latent load proportion from March to September. The high reheating ratio, i.e. from 60% to 90%, is found to be the main reason for the poor thermal comfort. Therefore, the LDCS which could handle sensible and latent loads separately was proposed. However, the electricity-driven LDCS was found not suitable for local commercial buildings. significant energy saving could be achieved by the solar-assisted LDCS system with thermal storage, when the installation area for solar collectors is larger than the minimum required one, i.e. 9.7m2/(kWm−2) for office and 12.7m2/(kWm−2) for hotel buildings. Energy saving of different system types with different installation areas was also studied. The solar-assisted LDCS shows more energy saving in winter but less in summer. Results and conclusions can be useful for researchers and local engineers. [Copyright &y& Elsevier]

Abstract: This paper explores the potential of reducing the annual energy consumption of a central air-conditioned building through advanced evaporative cooling systems. The building considered is a typical three floor library building of a University. The regenerative evaporative cooling technology is coupled with the liquid cooled water chiller system to accomplish the energy conservation objective. Comparisons of the regenerative evaporative cooling are made with simple evaporative cooling to bring out the importance such a system. The well-known building simulation software, TRNSYS is used to carry out the heat load calculations and the dynamic simulations of the building. Annual energy consumptions of different components of the air-conditioning system are estimated for the existing water chiller system as well as for both coupled evaporative cooling systems (simple and regenerative). The annual energy consumptions, the indoor temperature, the relative humidity and the thermal comfort index ‘PMV’ are compared for all the three different air-conditioning systems. The coupling of direct and regenerative evaporative cooling technologies with water chiller system has shown, respectively, 12.09% and 15.69% savings in annual energy consumption of the building, while maintaining PMV between −1 and +1 for most of the hours in the year. [ABSTRACT FROM AUTHOR]