Where Are the Key Directions for Green Buildings?

Among building energy consumption, energy used for heating, ventilation, and air conditioning (HVAC) deserves special attention. Therefore, when considering green buildings, the energy-saving potential in this area should be fully taken into account, with controls implemented at various stages including design, construction, commissioning, and operation management.

Design, Construction, and Commissioning – Not One Can Be Missed

A sound design should integrate comfort, economy, efficiency, and advancement, particularly with a reasonable understanding of the application of product technologies. For example, electricity consumption by air conditioners in China is increasing daily. Statistics show that air conditioner electricity consumption accounts for approximately 15% of the nation's total electricity consumption. During summer peak periods, air conditioning load can even reach as high as 40% of total urban electricity load, and this figure continues to rise. Long ago, the state issued a series of national standards concerning air conditioner energy efficiency, including the "Limited Values of Energy Efficiency and Energy Efficiency Grades for Room Air Conditioners," the "Limited Values of Energy Efficiency and Energy Efficiency Grades for Packaged Air Conditioners," and the "Limited Values of Energy Efficiency and Energy Efficiency Grades for Water Chillers." Design personnel should fully understand the energy-saving potential of new products and technologies, try to select products with high performance coefficients, and have a clear understanding of the energy-saving effects of these products.

If energy-efficient green buildings are still just theoretical exercises during the design phase, then construction is the most practical step. Currently, many buildings, including green building projects, suffer from poor construction quality and a disconnect from design, resulting in persistently high energy consumption for some buildings. For instance, some construction companies fail to recognize the importance of valves and instruments in piping systems. Because automatic valves are relatively expensive, they try to reduce the number of valves and instruments during construction to lower costs. Although this does not stop the piping system from operating, operators lack instrument data for reference during operation and cannot adjust valve openings as needed, leading to significant waste.

After the construction phase, system commissioning is an even more critical but easily overlooked issue. On this matter, industry authorities such as Professor Li Xianting from Tsinghua University have repeatedly emphasized its importance, yet industry acceptance remains less than ideal. Their view is that only well-commissioned systems can fully meet requirements and achieve operational energy savings. If system commissioning is unreasonable, the system capacity often has to be increased to meet design requirements, which not only wastes energy but also causes equipment wear and overload.

For example, some office buildings are put into use without proper commissioning. As a result, because the water flow in the podium's piping system significantly exceeds the designed flow rate, the high-rise main building does not receive enough air conditioning water. This forces operators to run two water pumps while operating only one chiller to meet the normal cooling needs of the high-rise offices, resulting in energy waste. Similarly, the quality of operation management determines whether operational energy consumption greatly exceeds expectations. According to requirements, management personnel should be able to operate equipment based on seasonal climate changes and the building's own characteristics. However, most projects lack quantitative indicators for training and assessing management and operations personnel, making it difficult to mobilize their enthusiasm – an area in urgent need of improvement. For example, in one project's air conditioning system with three chillers and three water pumps, because the water flow regulating valves were installed 3 meters above the floor and were inconvenient to operate, the chiller inlet and outlet valves remained open all year. When operating one chiller, two-thirds of the cooling water flowed into the two idle chillers, providing no cooling effect whatsoever. This required running two cooling water pumps to meet the normal cooling needs of a single chiller, causing substantial energy waste.

Government Leadership Remains the Primary Approach

To actively promote the development of green buildings, I believe the following issues need to be properly addressed:

First, strengthen research on energy-using systems. The primary investors in energy-saving equipment research are equipment manufacturers. For equipment manufacturers, research and development of energy-saving equipment can bring certain economic and social benefits within a relatively short period. Driven by this motivation, manufacturers invest substantial human and financial resources, which promotes the development of energy-saving equipment. However, research on energy-using systems is basic research, which is relatively more difficult. Moreover, different projects have different characteristics, requiring tailored solutions based on local conditions. Without relevant government policy support, the economic benefits are difficult to realize in a short time, which restricts research on energy-using systems.

Second, mobilize the enthusiasm of all relevant parties through policies and regulations. Although the state has successively introduced a series of laws and regulations regarding energy conservation, emission reduction, and green buildings in recent years, the relevant systems and management structures still have deficiencies. Economic incentive policies are not sufficiently clear, precise, or strong enough. For design and construction development personnel, green energy-efficient buildings come at the cost of sacrificing certain economic benefits. Therefore, the current rate of compliance with energy efficiency standards remains low. Practice has proven that building energy conservation is unlikely to develop spontaneously; it must be led by the government to advance the construction of a building energy efficiency regulatory system with clearly defined incentive policies. In this regard, the systems, methods, and reward and punishment policies that countries such as Singapore have been promoting in recent years are worth learning from.

In summary, to promote the development of green energy-efficient buildings, we must start from the aspects of design, construction, commissioning, and operation management, incorporate building energy efficiency projects into the construction process, and form a long-term management mechanism. At the same time, we should actively explore energy performance contracting (EPC) models, promote building energy efficiency work following a market-oriented approach, and fully realize the social and economic benefits of green buildings. Relevant government departments should also provide necessary policy support, adhere to the principles of adapting measures to local conditions, implementing measures step by step, and making steady progress, so as to achieve the ultimate goals of saving energy, protecting the environment, and realizing sustainable social development.