The central air-conditioning system commissioning project, completed jointly by the International Campus, Zhejiang University and the China Academy of Building Research, passed the assessment of experts on October 25, 2019. According to the data collected, the total energy consumption of the system was reduced by 28.7%, the indoor air conditioner noise decreased by an average of 3.9 decibels, and the indoor temperature variations were decreased by 2℃. This project has not only achieved positive energy saving results, but also improved the indoor comfort level of all the buildings on International Campus.
What is “commissioning”?
The technology of “Commissioning” originated in Europe and the United States. It’s use is mainly for the comprehensive implementation of “diagnose and treat” methods on building facilities systems which are already completed and in normal use, making the building facilities systems achieve comfortable and efficient operations.
The effects of “commissioning”
More comfortable and healthy indoor environment
The main indoor environment comfort level measuring indexes such as temperature, air quality and ambient noise have been significantly improved.
By adjusting the wind pressure and air volume uniformity, the original phenomenon of "warm overhead, chilly underfoot" has been apparently improved. Using the rooms in the Arts and Sciences Building as an example, the air temperature difference between the air outlet and the ground was reduced from 4.2℃ to 2℃. By setting and cleaning all the air conditioning system filters, the indoor fresh air exchange and cleanliness was improved. Adjusting the indoor fan coil, eliminated air leakage problems and other related issues and the noise from the indoor air conditioners were significantly reduced with an average of decreasing amplitude 3.9dB.
More efficient and low-carbon energy efficiency
By system “commissioning”, the air conditioning system energy efficiency has been greatly improved. Considering the measured energy consumption of air conditioning during the summer of 2018 and 2019 at the East Lake Complex for example, the total energy consumption of the system was decreased by 28.7%, saving 121,200 kWh of electricity. By the project “commissioning”, it is estimated that the annual energy consumption of the air conditioning systems of the whole university will decrease by more than 20%, saving energy consumption of about 400,000 kWh.
Safer and more sustainable operation guarantee
By “commissioning”, this project specially formed the operating instructions of the air conditioning system at the International Campus. The instructions will provide engineers of facility management and operation with more intuitive and easy-to-operate guidance on air conditioning system operation and maintenance. This will ensure the safe and sustainable use of the air conditioning system and a healthy, comfortable, and green indoor environment for teachers and students. It will also help the International Campus reach its goal of sustainable campus operations.
Main works of “commissioning”
The entire project was completed over one year, covering two air-conditioning cooling seasons and one heating season and the technicians conducted site surveys and tests for 93 days.
174 equipment system drawings were reviewed and analyzed and equipment performance of 223 air conditioning systems were tested on site.
More than 6000 items of test data were recorded and formed the statistical analysis text of 388 pages of field operation records.
According to the test results and the problems reported by users, 776 points of unreasonable operation or installation were identified.
It was reported that the air conditioning system project “Commissioning” was included in the National "13th five-year" key research and development program. It is not only a demonstration project for research on the key technologies of low-cost adaptation and operation management of large public buildings, but also the first large-scale university building project implemented by China Academy of Building Research. It will help guide practical engineering application with the research results of low-cost adaptive technology. The implementation of this project has achieved positive environmental and economic benefits and will also provide a model for sustainable operation of air conditioning systems in large public buildings and educational buildings throughout China.
