## 5 Conclusions  
The implementation of an air-to-water heat pump assisted by a photovoltaic system in rural medical centers represents a sustainable and highly efficient solution for air conditioning and hot water production. This system, constructed from two-liter plastic soda bottles, is an innovative construction that allows for heat insulation and, at the same time, better cooling of the internal environment without negatively affecting the interior from external conditions such as snowfall or extreme heat waves. Furthermore, solar energy is used to power the heat pump compressor and the electrical system of the small rural medical center. This implementation of solar energy significantly reduces electricity consumption from the grid and lowers the facility's carbon footprint. In rural areas, where access to conventional energy sources may be limited or expensive, this technology guarantees greater energy, which is especially important in contexts where the continuity of medical services is critical. Furthermore, the combination of renewable technologies helps stabilize long-term operating costs by mitigating the impact of energy price volatility. The seasonal efficiency of heat pumps can exceed COP values of 3, meaning that for every kWh of electricity consumed, more than 3 kWh of thermal energy is generated, optimizing energy  
Figure 5: The PV size and performance for the developed sustainable building: (**a**) Energy system evaluation under fully integrated and standard control in green building development; (**b**) \(SP_{gsg,grid}\) and \(SP_{gsg}\) evaluated under standard conditions and fully integrated conditions; (**c**) comparative SSR and SCR indicators. efficiency. The use of solar energy further improves the overall performance of the system, reducing payback times compared to conventional systems. It is even more important to avoid fossil fuels such as gasoline or diesel, which, in critical environments like healthcare, can be more harmful due to the odor, fuel combustion, and risk of internal accidents due to improper handling. This also translates into improved thermal comfort and health in rural medical spaces, where a stable and adequate temperature is essential for clinical care. The versatility of this system allows it to be adapted to different scales of demand, making it ideal for doctors' offices, health centers, or small rural clinics. Furthermore, the social and environmental benefits of the system are equally significant. By promoting the use of renewable energy in rural areas, a more equitable and inclusive energy transition is fostered, aligned with the Sustainable Development Goals (SDGs), particularly goals 3 (good health and well-being), 7 (affordable and clean energy), and 13 (climate action). Reducing greenhouse gas emissions contributes to mitigating climate change, while the use of a clean energy source like solar improves public perception of sustainable technologies. Furthermore, the installation of these systems can generate local employment in assembly, maintenance, and operation tasks, strengthening the community economy. Their relatively low maintenance and long component lifespan ensure continuous operation with minimal interruptions, which is crucial in healthcare facilities. It is also important to consider that this solution can be integrated into hybrid systems with a grid backup or generators to ensure continuous operation in low solar radiation conditions. Overall, the photovoltaic-supported air-to-water heat pump is presented as a technically and economically viable option, improving the energy resilience of rural medical centers and elevating the quality of medical care while promoting environmentally responsible practices. Solar-powered heat pumps have limitations that are associated with intermittent solar radiation, which can affect their performance on cloudy days or at night. Furthermore, system efficiency depends on an adequate thermal or electrical storage capacity to cover demands when solar production is not available.