Clean and economical air conditioning system

2001/09/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Arkitektura

Air conditioners consume a lot of energy, and if fossil fuels are burned, they emit carbon dioxide into the air. To solve these two problems, scientists at the University of Nottingham, David Etheridge and David Rae, have devised a clean and economical climate control system. The system is especially suitable for the climate of Northern Europe, that is, for areas where it is not very hot, since the temperature drops about 2-3 °C. The bases of the system are natural ventilation and phase change materials (PCM). These materials can be solid or liquid depending on the temperature.

During the day, through the fan, the warm air of the room is driven to tanks with solid PCM. The PCM absorbs heat from the air and slowly dissolves, while refrigerated air is pumped back into the room. At night the reverse process occurs.

First, the sense of the fan is changed and the cold night air is introduced into the room. Then, this cold air follows the same route as hot air during the day, but this time the PCM is in liquid state and solidifies when it comes into contact with cold air. The detached heat warms the air of the room and it is pumped out of it. In this way, the PCM is resolidified and is willing to repeat the same process the next day. For the system prototype, scientists used sodium sulfate as PCM.