English

The operation of air-cooled chillers accounts for significant energy consumption in local commercial buildings, and low operational efficiency especially under partial load conditions and poor control are part of reasons for such huge energy consumption. Chiller efficiency can be improved by enhancing heat transfer rate in condensers. This paper considers how the chiller performance can be improved by using water mist to pre-cool ambient air entering the condensers to decrease compressor power.

One of the major factors in HVAC design is the occupant load, both in terms of heat gains and fresh air needs. Internal heat gains that result from human occupancy, commonly use a predicted maximum occupancy and an estimated occupancy diversity factor. This may have two problems. First, the maximum number may be far away from true value, Secondly, in a dynamic organizational environment, it is not easy to get a good estimate of the occupancy diversity factor. This paper comes up with a new approach that informs the HVAC design process by organizational simulation.

District heating and cooling (DHC) systems show a great potential to save energy. However, DHC has a number of problems related to other systems within a building; for example, decrease in the temperature difference between the supply and return water carrying cooling and heating energy affects efficiency. The main reason is that the DHC plant and the building air conditioning systems are operated separately. This study proposes a new energy service in which the operator of the DHC plant controls air conditioning systems at the same time.

One of the most effective methods to reduce energy consumption in buildings is to install the advanced HVAC equipments and to control them properly. This paper describes the optimum HVAC control system through the developed data platform, BACFlex that the simulation is executed using BEMS data, the weather forecasting, etc. The concerned targets are CO2 generation, energy consumption, comfort and cost. The brief structure of the system is explained and an example applied to the school is introduced.

This article introduces two system models to simulate the energy performance of the temperature and humidity independent control air-conditioning system (THICS) and the conventional air-conditioning system (CAS). The energy performance comparison includes three parts of cooling resource, transportation system and terminal devices. A typical office building with these two different systems is numerically analyzed. Beijing and Guangzhou, two major cities in China, are chosen, which lay in temperate zone and tropical zone respectively.

Evaporative cooling is able to generate the cooling medium at a temperature approaching to the ambient wet bulb temperature. In this paper, a low-energy air conditioning strategy is proposed, which is a combination of cooled ceiling (CC), microencapsulated phase change material (MPCM) slurry storage and evaporative cooling technologies.

The modelling and prediction of human thermoregulatory responses and comfort have gone a long way during the past decades. Sophisticated and detailed human models, i.e. the active multi-nodal thermal models with physiological regulatory responses, have been developed and widely adopted in both research and industrial practice. The recent trend is to integrate human models with environmental models in order to provide more insight into the thermal comfort issues, especially in the non-homogeneous and transient conditions.

The noise generated by the crowds and organized fans during sporting events has created a challenge for sport facility management. The new demand for full compliance to National Football League rules on crowd noise, and cities' regulations on noise ordinance require new methods or approaches in measuring such environmental conditions. Given their dynamic range and possible classification, noise levels generated by large crowds have influenced the outcome of games, and recent analysis of the available data shows an increase in noise related penalties.

Control of daylight level using slatted blinds is an effective means of energy saving. But proper judgment on the presence of direct sunlight is indispensable. Lack of a function to disable blind controls in non-existence of direct sunlight may cause dissatisfaction about the view through windows among users of building. Therefore, this study was conducted with the aim of setting threshold values based on daylight conditions so that automatic controls are disabled and slats are horizontalized when direct sunlight is non-existence. 

In this paper, indoor thermal environment of the Terminal 1 of Chengdu Shuangliu International Airport (CSIA) is taken as study object, by means of investigating, measuring and simulating based on computational fluid dynamics (CFD) codes. A total of 569 participants provided 569 sets of physical data and subjective questionnaires, and an indoor thermal comfort meter was used to collect the measured parameters of the indoor environment and the predicted mean vote (PMV). The accepted thermal comfort environment range is obtained.