An evaluation model for individual thermal comfort is presented based on the BP neural network. The train data came from a thermal comfort survey. The evaluation results of the model showed a good match with the subject’s real thermal sensation, which indicated that the model can be used to evaluate individual thermal comfort rightly. Taken a room air conditioner as an example, the application of the NNEM in creating a microenvironment for individual was discussed. The result showed that the NNEM can play an important role of connecting individual thermal comfort with the control on the air conditioner.

A strategy based on the data mining (DM) method is developed to detect and diagnose sensor faults based on the past running performance data in heating, ventilating and air conditioning (HVAC) systems, combining a rough set approach and an artificial neural network (ANN). The reduced information is used to develop classification rules and train the neural network to infer appropriate parameters. The differences between measured thermodynamic states and predicted states obtained from models for normal performance (residuals) are used as performance indices for sensor fault detection and diagnosis. Real test results from a real HVAC system show that only the temperature and humidity measurements of many air handling units (AHU) can work very well as the measurements to distinguish simultaneous temperature sensor faults of the supply chilled water (SCW) and return chilled water (RCW).

Conception of combination of gas-engine-driven heat pump (GHP) and water-loop heat pump system (WLHPS) is firstly presented in the paper in order to reduce the energy consumption of air conditioning system further. Design of the new system is introduced through an actual project in China and compared with a conventional air-conditioning system (CACS) and conventional WLHPS (EHP-LHPS) in terms of technical characteristics and payback period. It is found that the payback period of GHP-WLHPS is about 2 years when compared with CACS and 2.6 years with EHP-WLHPS on the average. So it is worth being more widely applied. And several barrier to application are also discussed.

Degradation of formaldehyde with different initial concentration over titanium dioxide was carried out in a photocatalytic reactor. Photocatalytic rates were well described by the simplified Langmuir-Hinshelwood model. The kinetic analysis shows that the apparent first-order reaction coefficient is lower and half-life of photocatalysis is longer for low concentration than for high concentration formaldehyde. A network formation model of the photocatalytic products was established. Experimental results and analysis demonstrate that carbon dioxide concentration and carbon monoxide concentration in gas phase vary exponentially with the illumination time and may be even higher than gas-phase formaldehyde concentration if there is much pre-adsorbed formaldehyde in adsorption equilibrium on catalysts before illumination. Carbon monoxide is found to be one of the by-products during formaldehyde photooxidation.

A new type of air supply system, chair-back air supply system (CASS), in an air conditioned railway carriage in China is firstly presented in the paper by simulating the types of air distribution commonly used in the carriage and by comparing the results with prototype experiment. And evaluations on therma comfort and economy are also carried out. It is found that the CASS has its special advantages of better air distribution and better energy saving by comparing it with the other conventional air supply systems. Furthermore, it is much easier for the system to work in with the setting of air-conditioning units in the lower part of the carriage, which will meet the trend of high-speed of the carriages.