NAC wall: An open cycle solar-DEC with naturally driven ventilation

This paper presents the general concept of the NAC (Natural Air Conditioning)-wall system and some experimental results on a first prototype. The originality of the system is to perform a solar DEC (Desiccant, Evaporative Cooling) open cycle by exploiting natural buoyancy driven ventilation, thus avoiding the use of fans.

The supply air is dehumidified by a zeolite based adsorption bed and is cooled indirectly by an evaporative cooler, through a low pressure heat exchanger.

Low-energy cooling conception in office buildings.

Air conditioning is widely used in the office building sector in the French Mediterranean region. Though often a «sine qua non» for renting office space, there is however a widespread feeling that operating and maintaining air-conditioning systems can be troublesome (unreliability, regulation and maintenance difficulties, non uniform comfort conditions, high prices are frequently lamented).