## 4 Case Study  
### Geographical Site, Buildings, Existing Plants and Energy and Water Supply  
In December 2017, an integrated AWG machine was tested in a worker village in the industrial side of Dubai. In Figure 2, the installation site is shown. The worker village is placed at about 15 km from the shore and 5 km from the weather station of the Al Makatoum International Airport.  
The worker village is composed by tens of residential buildings, each of them housing 200 guests. There are various common kitchen buildings, where meals are prepared and served in turns. Kitchens are equipped by an air conditioning system, composed by fans, moving external air inside an air duct, air vents and splits. The fans work continuously during the year, providing about 12 m\({}^{3}\)/h of fresh air, while the splits were estimated to work continuously only from April to October, with an average EER of 3.5, providing the air cooling and dehumidification. It was estimated that cooling starts working when the outside temperature is over 20 \({}^{\circ}\)C, because, due to internal loads, in such a case, air changes by themselves are not enough to give internal comfort.  
The tap water comes from the desalinisation system. Such a water is employed for domestic uses, such as showers, toilets and general washing, not for human consumption. It was estimated that each building, housing 200 guests, working in turns, needed to heat 18,000 L/day of tap water, from 10 \({}^{\circ}\)C to 50 \({}^{\circ}\)C. The installed heating plant is represented by 24 electrical boilers of 2 kW of power each, with an efficiency of 95% and about 18 h of daily work. Drinking water is provided to guests by means of bottled water. To each guest, 2 L/day of drinking water are supplied by means of half-litre bottles (four bottles/day).  
The kitchen building is equipped by an LPG boiler of 125 kW, with a calculated efficiency of 70%, connected to a hot water tank of about 3 m\({}^{3}\). The daily provided hot water is between 20,000 and 22,000 L/day, and the required temperature is 50 \({}^{\circ}\)C. The cold water, for domestic uses, comes from the municipality, which delivers desalinated water by means of the aquduct.  
The test was carried out in a worker village, because such a kind of settlements are diffused in United Arab Emirates (UAE). Actually, Ministerial Resolution 44 of 2022 establishes that, whenever 50 or more workers, with earnings under 1500 AED/month, are employed, they must be accommodated in proper settlements that should answer to precise standards regulated by the law. In particular, besides proper room sizes, it is specified that the accommodations must be provided with drinking water, common kitchens, air conditioning and hot and cold domestic water [41]. Due to the technology peculiarities, described in Section 2, the integrated AWG machines employment can be particularly effective whenever more than one useful effect of the reverse cycle is required at the same time. In the case of the worker villages, all the potentialities of an integrated AWG machine can be required, because, following the Ministerial Resolution 44 of 2022 rules, there are needs of drinking water, cold and dry air and heating energy for domestic water, all at the same time. Thus, worker villages are a good benchmark for integrated AWG installation.