## 4 Analysis and Discussion  
To compare the systems, a lifecycle of ten years was considered because swimming pools use chlorine, which is corrosive. Even though ASHRAE recommends 15 years for  
Figure 6: Internal content of a desiccant wheel (adapted from [22]).  
heat pumps, the 10-year value is based on the ASHRAE Equipment Life Expectancy chart for self-contained machine [32]. Specific information about swimming pools is not found in the ASHRAE standards, so in the simulation performed, an equipment use factor of 40%/year was used, due to temperature variations and possible openings of mobile roofs in the summer.  
Equation (5) shows a 10-year interpretation of the TEWI indicator for dehumidification [24,28]:  
\[\begin{array}{l}\text{TEWI}_{\text{Dehumidification}}=\text{GWP}\text{ (direct, refrigerant leaks including EOLC) +}\\ \text{Power input}\cdot\text{Use factor}\cdot\text{8760}\cdot\text{8}\cdot 10\end{array} \tag{5}\]  
The classified variables are indirect emissions, which are the fluid used is fluid R 410A with GWP = 2088, with a refrigerant weight of 5 kg per equipment (10 kg for a total of 2 machines) [33]. A useful life of 10 years was the considered with a leakage rate of 12.5% per year (\(L_{annual}\)) and a recovery rate of 70% (\(\alpha_{recovery}\)) of the refrigerant fluid [34]. The values are the same regardless of the countries in question. By applying Equation (2), the direct emissions component was 323,640 kg (CO\({}_{2}\)) [35, 36, 33, 34].  
The annual energy emissions in Brazil were 240,510 kg (CO\({}_{2}\)) for the refrigeration de-humidification system and 351,520 kg (CO\({}_{2}\)) for the desiccant wheel system. In the USA, it is 1,139,710 kg (CO\({}_{2}\)) for the dehumidification system refrigeration and 166,573 kg CO\({}_{2}\) for the desiccant wheel system, as shown in Figure 7. The total emission values are shown in Figure 8 for both countries.  
Figure 8: Refrigeration vs. desiccant wheel emissions for Brazil vs. the USA.  
Figure 7: CO\({}_{2}\) emissions for 10 years [4].  
It is possible to verify that the best eco-energy option for Brazil is the desiccant wheel, while for the USA it is the refrigeration system. This difference is due to a more sustainable energy matrix. The weight of the GWP of the refrigerant fluid is very high, specifically in a refrigeration dehumidification system in Brazil. Throughout the life of the equipment, the refrigerant gas is responsible for 57.5% of kgCO\({}_{2}\) emissions, while in the USA, the refrigerant fluid only contributes 22%.  
Another important observation is that the two options have a difference of 38% in Brazil and 12% in the USA, that is, the desiccant wheel option in Brazil is much better than the refrigeration option in the USA.  
Since the difference is small in the USA, it must be considered that the desiccant wheel has a lower noise level and also fewer moving parts; therefore, it can be an advantage to use such technology, but it is worth remembering that the corrosion of copper coil is greater than that of silica wheels. Although they are not yet highly commercial, there are refrigerants, such as HFO (based on hydrofluoroolefin), with a low GWP value of 466 that may be strong alternatives in the near future. The simulation is extended to the comparison with this new alternative refrigerant [36; 37; 38], as shown in Figure 9.  
Using low GWP refrigerant such as R454-B, the best option for dehumidifying swimming pools is refrigeration, but even so in countries with more sustainable energy matrices such as Brazil, the refrigeration system was only 12% more efficient in terms of emissions, that is, even with HFO the refrigerant gas it has a large environmental impact.