Bởi vì điều hòa nhiệt độ bay hơi đòi hỏi tương đối ít năng lượng, và bởi vì sự hiện diện của ánh nắng mặt trời mạnh thường trùng hợp với nhu cầu làm mát, một liên kết giữa năng lượng EAC và năng lượng mặt trời sẽ xuất hiện hấp dẫn (xem hình và cho một sơ đồ và hình ảnh một). | Solar Evaporative Air-Conditioning Because evaporative aứ-conditioners requữe relatively little energy and because the presence of strong sunshine often coincides with the need for cooling a link between EAC and solar energy appears attractive see Figures and for a schematic diagram and a picture . Only a few suppliers offer solar-powered aữ-conditioners however even in the southwestern United States the heart of the EAC industry. Companies supplying these devices apparently aim for other markets such as developing countries where grid electricity is not yet common. The Market It is apparent from Table that only a very few sources are suppliers of solar EAC. Moreover inquir- Figure . A Solar-Powered Evaporative Air-Conditioner Solar PV panel array Ambient aứ in Axial fan Evaporating pad media Air distribution baffle Water storage with recirculating pump Supply air out Source ECI. 37 38 Evaporative Air-Conditioning Applications for Environmentally Friendly Cooling Table . Available Packaged Solar Evaporative Air-Conditioning Equipment Supplier Type Rated capacity Required solar capacity Approximate cost including PV modules Jade Mountain Window 25 m3 min 60 Wp US 1 400 Jade Mountain Home 75 m3 min 300 Wp US 4 500 Solar Energie Technik Portable 10 m3 min 110 Wp US 2 500 Source Authors. ies of suppliers indicate that only a few units have been sold so far probably only a few hundred worldwide to date . The attractiveness of solar EAC depends largely on the availability and cost of electric power. Because photovoltaic PV power may cost US kWh or more compared with US kWh for power from the grid PVs are most likely to be cost effective where grid power does not yet reach. Nevertheless solar evaporative aữ-conditioning is a proven technology that can be very useful and efficient in such circumstances. Optimizing Evaporative Air-Conditioning Design for Solar Operation Because of the high investment cost of solar panels 90 percent of the cost of