Water Extraction from Air by Refrigeration—Experimental Results from an Integrated System Application

Water is an indispensable resource for life. Several technologies have been studied and used in the past to extract water from the ground, the air or the sea. The technologies vary depending on community needs and resources. In developed countries, air conditioning systems are widespread, and the use of condensed water from air conditioning systems is of potential interest. In hot and dry climates, in arid regions where refrigeration processes represent a basic need for indoor comfort, advantages of an integrated design of HVAC (Heating, Ventilation and Air Conditioning) systems optimized for water production rather than for air treatment could be evaluated. In the current work, a real application, which embodies savings of both energy and drinking water, is presented. It represents an evolution of a previously studied integrated system to simultaneously provide air conditioning and water to a hotel. The main target of this system is to meet drinking water requirements and, secondly, to provide domestic water heating and primary air for a non-conditioned zone. Main features of the integrated system are outlined, the needs of the hotel are described, and calculations of water and energy savings are presented. Moreover, a simulation tool was developed with the aim to evaluate possible water savings in a one-year period and to improve the efficiency of the system. A method to verify the effectiveness of the integrated system is also described.