1. Importance of Energy Conservation in HVAC Systems
   In recent years, severe smog in China has significantly affected people’s daily lives and health. The rapid urbanization and industrialization have led to enormous energy consumption. With the introduction of China’s sustainable development strategy, energy conservation and emission reduction have become primary goals. Currently, building energy consumption accounts for over 30% of the total energy consumption in the country, and this figure continues to rise. HVAC systems are essential equipment in modern urban buildings, and the different installation technologies significantly impact their energy consumption. HVAC systems rely on electricity to operate, consuming large amounts of non-renewable energy.
2. Current Status of Energy Conservation in Heating and Air Conditioning Systems
   Although China is continuously improving its energy-saving design and innovation capabilities for HVAC systems, many issues remain. Research on HVAC energy conservation in China started much later than in developed countries, leaving many technologies still immature. There are significant design problems in equipment, and the lack of technological advancement leads to substantial flaws during the design phase. The importance of energy conservation in HVAC design is paramount, yet research in this area is weak, and relevant departments often overlook its significance. This results in high costs during the design and construction of HVAC systems, leading to high energy consumption during operation, which negatively impacts efficiency and increases the burden on users, hindering energy savings and environmental protection. Effective energy conservation in HVAC systems requires collaboration among designers, operators, and users. Despite increasing demands for energy conservation and environmental protection, new technologies are still in their infancy and have not been effectively applied to HVAC systems. Construction units often believe that meeting design and installation standards is sufficient, neglecting the need for adequate training for management personnel. Operators often lack understanding of how to adjust HVAC systems based on outdoor temperature parameters, leading to significant resource waste. People’s awareness of energy conservation remains low; although low-carbon economy and lifestyle are promoted, many do not fully grasp the concepts. The pursuit of comfort often overshadows energy conservation, leading to excessive energy consumption.
3. Proposed Energy Conservation Measures
   In summer, the exhaust temperature of air conditioning systems is significantly lower than that of outdoor fresh air, with lower humidity levels as well. Heat recovery devices can be used to exchange heat between exhaust air and fresh air, effectively reducing the temperature and humidity of the incoming air. In winter, the exhaust temperature is higher than the outdoor temperature. Heat recovery devices can preheat and humidify fresh air. Specifically, heat exchangers can be installed at exhaust outlets to utilize the residual heat from exhaust air to warm incoming air, achieving waste heat recovery. Current heat recovery devices mainly include sensible heat recovery and total heat recovery types, significantly enhancing energy reuse and conservation. Natural gas is a primary energy source in cities, but its direct combustion leads to substantial energy waste. Generating electricity from natural gas and using the residual heat for heating and cooling can improve energy utilization efficiency.

When selecting pumps, excess capacity often leads to throttling losses at partially opened outlet valves,    affecting the cooling efficiency of the main unit. Variable frequency drive technology can be employed     to fully open valves, resulting in significant energy savings. By adjusting the power of the main unit        according to the actual load of the air conditioning system and analyzing the cooling load within buildings, multiple plans can be developed to identify the most effective solution for reducing energy consumption. Moreover, compressors can absorb large amounts of low-grade heat energy from heat sources, raising the temperature for reuse. Heat pump technology can achieve this goal, allowing for large-scale utilization of low-temperature heat energy from rivers, urban sewage systems, industrial wastewater, soil, or air. This technology effectively saves primary energy by converting low-temperature energy into high-temperature energy for use. Under certain conditions, heat pumps can also provide cooling, reducing primary energy consumption and minimizing emissions of pollutants generated by energy combustion, making it a vital new energy-saving technology for sustainable development.

We should vigorously promote energy-efficient HVAC systems. Although many energy-saving HVAC products are available in the market, their prices are often not ideal, leading consumers to choose cheaper options over more efficient products. This situation calls for market price regulation by the government and relevant departments to ensure that energy-efficient products are more accessible. During the research and design process, it is crucial to guarantee quality and energy-saving effectiveness while minimizing costs by using lower-cost construction materials, thus promoting broader adoption of energy-efficient products. Market regulators should strengthen oversight of HVAC energy-saving products, as the market is still dominated by a few large enterprises with relevant technologies, leading to monopolistic tendencies. It is essential to raise public awareness about the importance of energy conservation. While there have been achievements in promoting energy-saving concepts and environmental protection, practical implementation remains lacking. Enhancing designers’ awareness of energy conservation and introducing advanced energy-saving technologies and concepts will help strengthen the energy-saving consciousness in HVAC systems.

4. Problems in Energy Conservation Design of HVAC Systems
   With the construction of resource-saving and environmentally friendly societies, the building industry faces higher demands for energy conservation and environmental protection, especially concerning HVAC systems. Different design schemes lead to significant variations in evaluation results. The lack of reasonable design scheme evaluations often renders energy-saving designs ineffective. The energy-saving effectiveness of HVAC systems is directly influenced by design quality. However, designers often overlook energy conservation issues, and the building industry’s design philosophy primarily caters to developers, who prioritize their economic interests and aim to shorten design and construction cycles. Consequently, design units focus on quantity over quality, leading to overlooked design issues that increase installation costs and energy consumption during operation, exceeding national regulations.

Many errors or omissions occur during the HVAC design process, which are difficult for designers to recognize. This necessitates careful review of design drawings by audit personnel to identify and address existing issues. However, in practice, the auditing department often functions merely as a formality, failing to fulfill its role, resulting in significant quality risks and increased energy consumption during operation. Some organizations believe that merely meeting design and construction requirements is sufficient for energy-saving plans, neglecting training for HVAC equipment and operators. This lack of understanding leads to significant energy consumption due to operator randomness and delays. Effective energy conservation design in HVAC systems is crucial, especially as global energy consumption rises rapidly, with building energy consumption increasing annually. While there is a focus on vehicle energy consumption, building energy consumption is often overlooked. Research on HVAC energy conservation is essential as resource scarcity drives up energy prices, causing fatigue and frustration. Effective energy conservation can reduce costs and yield significant social benefits while mitigating environmental pollution caused by energy use. For instance, burning fossil fuels releases large amounts of CO2, nitrogen oxides, sulfur compounds, and particulate matter. Researching energy conservation in HVAC systems can reduce emissions and effectively control environmental impacts.