**8.2. Thermodynamic cycle cost**

For the air-conditioning systems, there are just a few certified companies to build these devices. People have lack of information about the uncommercial devices. Considering than a conventional air-conditioning by compression is based on an evaporator, a condenser and a compressor, two of those heat exchangers are the same for an absorption cycle, but the metal is so different. In compression systems, aluminum and copper are used for the cycle. In an absorption cycle, the metal for the heat exchanger is stainless steel to avoid corrosion problems. This is a disadvantage for the cost because the cost of the stainless steel is higher than copper. Nowadays, the SS 304 has an average price about 1.62 USD by pound; aluminum has an almost constant price about 1.58 USD by pound, and copper has unstable price around 2.87 USD by pound.

**Figure 10.** Cost for solar concentrator parts.

The heat exchanger areas are not the same for copper, aluminum or stainless steel because the thermal conductivity is quite different: copper is 386 W/mK, aluminum is 204 W/mK, and SS is 45 W/mK. This means that the thermal conductivity of the stainless steel is nine times lower than the copper.

Therefore, the four heat exchanger for the thermodynamic cycle must be costly, compared with a conventional compression air-conditioning, about 4.5 times the cost, based on the thermal conductivity and the cost today.
