## 4 Eco-Friendly Air-Conditioning
In conclusion, advancements in green refrigerants, heat recovery technologies, energy-efficient components, and sustainable manufacturing practices collectively contribute to a more sustainable approach to outdoor cooling, establishing new industry standards for energy efficiency and sustainability, and providing essential solutions in the face of significant climate change-related challenges [45]. Multiple reasons, including consumer demand for sustainable goods, technology breakthroughs, and more rigorous environmental legislation, are influencing the continuous change in the air conditioning sector towards eco-friendly solutions. The transition towards green refrigerants is notable because it signals a break from the usage of HCFCs and HFCs, recognised as significant contributors to global warming and ozone depletion. Adopting alternative refrigerants such as hydrofluorocatene, ammonia, and carbon dioxide is a systemic reaction to global environmental concerns and not only a technical shift. This is bolstered by international accords such as the Montreal Protocol, which has established timelines for eliminating ozone-depleting compounds and fostered innovation in the industry. Heat recovery technology is an essential innovation in the search for environmentally friendly air conditioning [45]. These systems cut energy consumption by collecting and recycling waste heat and contribute to energy efficiency and sustainability objectives. This is particularly significant in commercial and industrial contexts, where substantial waste heat may be recycled for other energy-intensive activities, producing a more connected and efficient energy ecosystem [46]. This multifaceted approach to sustainability emphasises energy-efficient components such as high-efficiency compressors, fans, and heat exchangers. These components are intended to perform optimally, decreasing the air conditioning system's total energy consumption. This coincides with environmental goals and translates into economic gains via lower operating costs, creating a win-win outcome for both customers and the environment [47]. Sustainable manufacturing techniques are expanding the notion of environmental friendliness beyond the product to include its entire lifespan, from production to disposal. Manufacturers increasingly emphasise eliminating waste, employing recycled or recyclable materials, and decreasing energy and water usage throughout the manufacturing pro cess. These behaviours adhere to the circular economy's ideas, encouraging a regenerative approach to production and consumption. Compliance with regulations acts as both a catalyst and a foundation for these adjustments. Laws such as the Montreal Protocol [48] have placed the sector on the road to greater sustainability by regulating the phase-out of dangerous compounds and encouraging the use of energy-efficient technology. These rules sometimes include economic incentives, such as tax breaks or subsidies, which make it financially feasible for businesses to participate in the research and development of environmentally friendly technology [44]. In conclusion, the transition to ecologically friendly outdoor air conditioning systems involves a complete endeavour involving various stakeholders, including manufacturers, regulators, and consumers. Advances in green refrigerants, heat recovery technology, energy-efficient components, and sustainable manufacturing processes lead to a more sustainable approach to outdoor cooling. These achievements are vital for facing the substantial problems faced by climate change and environmental degradation as they establish new industry standards for energy efficiency and sustainability. Figure 5 is a graphical figure to explain the eco-friendly air conditioning.