In this paper exergy analysis is used to assess the performance of the three most common air conditioning plant schemes: all-air, dual-duct and fan-coil systems. The results are presented in terms of flow diagrams to provide a clear picture of the exergy flow across the systems. The most relevant outcomes are that the air cooling and dehumidification is the process most responsible for the exer...

The National Renewable Energy Laboratory (NREL) has developed a transient air conditioning (A/C) system model using SINDA/FLUINT analysis software. It captures all the relevant physics of transient A/C system performance, including two-phase flow effects in the evaporator and condenser, system mass effects, air side heat transfer on the condenser/evaporator, vehicle speed effects, temperature-d...

ENSC 461 (S 11) Gas Vapor Mixtures and HVAC 1 Gas Vapor Mixtures and HVAC Atmospheric air normally contains some water vapor (moisture). The dry-air contains no water. Although the amount of water vapor in the air is small, it plays a major role in human comfort and thus in air-conditioning applications. The temperature of air in air-conditioning applications ranges from about -10 to 50°C. In t...

The frrst part of this paper presents carbon dioxide air conditioning units which were installed in two city buses. The two buses were tested "on-the-road" during summer 1997 in Bad Hersfeld, Germany. By the end of 1997, the air condition systems of the two buses had been running together for more than 860 hours proving that C02 systems fulfill important on-the-road requirements. In the second ...

Air conditioning control systems are commonly installed in restaurants, commercial buildings, office buildings and institutional buildings in Hong Kong. The systems invariably involve the use of fans for moving the air, filters for cleansing, ducts for air distribution, a control system for regulating the amount of heating or cooling automatically and a refrigerating plant connected to the heat...

The classical conditioning of the eyelid motor system in alert behaving rabbits has been used to study the expression of Fos in the hippocampus, and in the occipital, parietal, piriform and temporal cortices. Animals were classically conditioned with both delay and trace conditioning paradigms. As conditioned stimulus, both short and long (20 and 100 ms) tones (600 Hz, 90 dB) or short, weak (20...

The introduction of new refrigerants into the marketplace to replace CFC's banned by the Montreal Protocol has generated new research, required a review of many refrigeration concepts, and has raised new safety issues. One aspect that required further study occurred because some of the new refrigerants have a higher working pressure in the refrigeration and air conditioning equipment. This caus...