air conditioning

One of the major means of air diffusion for air conditioning equipment is the displacement ventilation. The stack effect is used by introducing at a very low speed, in the lower part of the room, some air whose temperature is close to the one of the desired atmosphere.

This paper aims at estimating the thermal comfort in environment created by a proposed passive evaporating cooling system. The evaporative effect from water falling along guides is used to produce a reduction in the temperature of the air entering the building.

This paper introduces a new strategy approach for the room air conditioning including classification and terminology. The aim of the classification is not to value one strategy over another (piston, stratification, zoning and mixing strategies are presented with their advantages and drawbacks, design criteria and applications) , it is up to the designer to select the most desirable strategy for each case. A clear classification of the ideal strategies will help the evaluation of the present room air distribution methods in different operating conditions.

This paper deals with the results of a large-scale survey performed to develop new notions about ACT (adaptive comfort temperature) in buildings in humid sub-tropical Hong-Kong ; the aim was to determine the adaptive interface relationship between indoor comfort temperature and outdoor air temperature in order to preset the indoor air temperature as a function of the oudoor air temperature.

The use of humidistats to control air conditioners may create mold problems mainly in houses unoccupied for an extended period. This article looks for the best approach to control humidity in empty homes during hot and humid summers. Several solutions are proposed.

The article discusses the design of the system with heat recovery to be used for the ventilation/air conditioning of a swimming pool building, in which air reaches high temperatures and humidities. The systems described and analysed use heat recovery through air to air heat exchanger or heat recovery through heat exchanger and heat pump.

This paper shows that it is possible to calculate the optimal outdoor air rate at different outdoor temperatures in the economiser cycle. The price of heat must increase 3 times before the optimal outdoor air rate during heating gets lower than during cooling. The optimal outdoor air rate during heating is determined primarily by the price of heat. The optimal outdoor air rate during cooling is determined primarily by the price of cooling capacity.

Using results from dynamic simulations, the article compares the energy consumption for the air conditioning of an industrial building with mixing and displacement ventilation.

In that study, Volatile Organic Compounds levels found in two tropical office buildings are analysed. The concentrations have been measured under different conditions of ventilation (normal occupancy with ventilating system working, and with the ventilation system shut down).

The article describes the different types of cold beams used to cool rooms from cold water. Passive cold beams mainly exchange through radiation and natural convection ; they include no fresh air introduction. Active cold beams are mainly based on forced convection, hot air from the room being induced by fresh air. Mix systems try to combine radiation and forced convection. Main characteristics and advantages of cold beams as well as system design rules are also briefly given.