# Energy Optimization in Hotels: Strategies for Efficiency in Hot Water Systems
## 4 Results and Discussion
### Comparison of Results with Literature  
The reviewed studies provide a broad overview of the evolution and diversification of heat recovery technologies in air conditioning and hot water systems. Most of the contributions emphasize improvements in COP and energy efficiency, highlighting strategies such as optimizing mass flow rates, temperature control, and integrating storage systems. However, many of these studies are conducted under ideal or controlled conditions, which may limit their applicability in real-world hotel environments, where the demand fluctuates significantly throughout the day and seasons.  
The present study builds upon these prior contributions but distinguishes itself by integrating a rule-based operational strategy and evaluating its impact over a complete 24-h period. Unlike earlier approaches, this model captures the operational dynamics of DHW systems typical of tropical climates, accounting for realistic occupancy patterns and consumption behaviors. Additionally, by simulating different levels of auxiliary heating usage, the methodology allows for a more granular analysis of cost-effectiveness and environmental performance. This makes the current research a valuable step forward in bridging the gap between theoretical efficiency and practical implementation in hotel infrastructures.  
Table 4 presents a comparative summary of recent studies focused on heat recovery technologies in air conditioning and domestic hot water systems. The table highlights the technological approaches, key operational variables, and main outcomes reported in the literature. This comparison provides a foundation for understanding the performance potential of different configurations, as well as the limitations and opportunities that exist when applying these systems in real-world scenarios. Particular attention is given to studies that propose optimization strategies, either through improved component design or operational rules, which are relevant to the methodology adopted in the present research.  
The flexibility of the model and the computational tools employed facilitate its adaptation to various facilities in tropical regions, as well as the exploration of dynamic adaptation scenarios, including periods of low occupancy and smaller hotels, providing a solid foundation for evaluating and improving energy strategies in these contexts.  
\begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline \multirow{2}{*}{**Equipment**} & \multirow{2}{*}{
\begin{tabular}{c} **Total** \\ **Power (kW)** \\ \end{tabular} } & \multicolumn{2}{c}{**Current System**} & \multicolumn{2}{c}{**Optimized System**} \\ \cline{3-8}  & & **Operating** & **Energy Cost** & **Emissions** & **Operating** & **Energy Cost** & **Emissions** \\  & & **Time (h)** & **(S/Year)** & **(kgCO\({}_{\text{2}}\))** & **Time (h)** & **(S/Year)** & **(kgCO\({}_{\text{2}}\))** \\ \hline \hline \(\text{B}_{\text{CIRC}}\) & 2.20 & 24 & 13.55 & 1292 & 24 & 5.53 & 527.59 \\ \(\text{B}_{\text{SCSC}}\) & 1.50 & 24 & 58.45 & 5287 & 24 & 27.48 & 2620 \\ \(\text{C}_{\text{LIC}}\) & 99.00 & 18 & 4644 & 282.6 & 6 & 1172.39 & 192.19 \\ \hline Total & 102.7 & 24 & 4713 & 6862 & 24 & 1205.41 & 3219 \\ Savings & & & & & & 3507.6 & 3643 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Economic analysis and associated environmental impact.  
\begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Cost Items** & **Unit** & **Current System** & **Optimized (100\% Use)** & **Optimized (25\% Use)** \\ \hline Initial cost & USD & 1591.97 & 1591.97 & 1591.97 \\ Operation (energy) & USD & 4713.01 & 3153.26 & 1172.39 \\ Maintenance & USD & 37.06 & 37.06 & 37.06 \\ LCC (Life Cycle Cost) & USD & 113,251.00 & 86,068.46 & 50,615.34 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Life cycle cost and environmental impact of the operating strategies.