Energy-Saving Renovations Reduce Annual Utility Costs for HVAC Heat Sources by 500 Million Yen (60%) | EXPERTISE

Moving Away from the Building with the Highest Carbon Dioxide Emissions in Kyoto

The Kyoto Station Building (completed in 1997) was a building with extremely high energy consumption—more than 130 percent of the average for buildings of its type. In 2010, a proposal process was launched to transform it into an energy-efficient building, and Nikken Sekkei was selected for the project.
From the project’s inception through design, construction, and operation, Nikken Sekkei served as the client’s technical consultant, providing comprehensive management of the performance verification team and contractors, and successfully completed the energy-saving retrofit within the planned budget and schedule.
Here, we will briefly explain the initiatives that led to a 60 percent reduction in utility costs.

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Kyoto Station Building (Completed in 1997)

Collaboration with Japan's Leading Experts

For this project, the Building Services Commissioning Association (comprising Professor Emeritus Harunori Yoshida of Kyoto University, Professor Takashi Yanagihara of Tokyo Denki University, and Professor Yasuyoshi Akashi of the University of Tokyo　Professor Yasuyoshi Akashi, and Professor Yoshiyuki Shimoda of Osaka University, among others) formed the energy-saving performance verification team. Nikkenseki collaborated closely with the verification team, pooling their expertise to handle the renovation design and supervision.
Performance verification meetings have been held from the initial design phase through the present, and energy-saving improvements continue to be implemented. This initiative has been selected for the Ministry of Land, Infrastructure, Transport and Tourism’s “Pioneering Project for CO₂ Reduction in Housing and Buildings (Heisei 26, 2nd Round).”

Total floor area: 238,555 m²; designed by Hiroshi Hara + Atelier Fai Architectural Research Institute

Implementing Energy-Saving Renovations Without Interrupting Business Operations

Although the Kyoto Station Building primarily uses steam as its heat source, it was estimated that approximately 25% of the heat from the high-temperature steam was being lost due to the facility’s east-west orientation.On the other hand, since switching to LED lighting had created a surplus in contracted power capacity, it was decided to reduce steam usage and switch to a heating system primarily based on inverter-controlled turbo units, which are the most efficient for producing chilled water.
For the renovation, we conducted a thorough preliminary survey and determined the heat source capacity required for each month, thereby reducing the total heat source capacity.Furthermore, during the heat source conversion work, we operated only the heat sources necessary at that time and utilized the remaining idle space for replacement, enabling us to update the heat sources without any impact on normal operations.

Upgrade to a system centered on inverter turbochargers

Achieved a 56% reduction in energy consumption in the first year!

Following the renovation, energy consumption in the spring, summer, and fall generally achieved a 60% reduction compared to the target. In contrast, the reduction in winter was only about 50%, falling short of the target; however, we plan to further reduce consumption in the future through measures such as converting steam to hot water.

Actual Energy Consumption in Renovated Areas

Costs for Renovating Aging and Deteriorating Facilities + Investment Amounts for Performance Improvements

BIM Model of the Heat Source Machine Room on the 3rd Basement Floor: Renovation Concept

Kyosuke Takano

Executive Officer
Engineering Department
Representative of the Sustainable Engineering Group

In 1989, after completing his graduate studies at the Waseda University, he joined Nikken Sekkei. As a mechanical engineer in the MEP department, he gained experience on new construction and renovation projects and engaged in comprehensive project management.Since 2016, in the Life Cycle Design Division, he has been in charge of renovation projects focused on comprehensive energy conservation and environmental sustainability for both architecture and building systems. For the Kyoto Station Building Heating and Air Conditioning Renovation Project, he received the Energy Conservation Grand Prize, the Japan Society of Heating, Air-Conditioning and Sanitary Engineers Renovation Award, and the Carbon Neutrality Grand Prize.He promotes a business model that continuously provides LCD (Life Cycle Design) services to address client challenges, handling a wide range of tasks including building systems deterioration diagnostics, the formulation of medium- to long-term maintenance plans, heritage preservation, asset utilization, and carbon neutrality initiatives. He is a Certified Building Systems Engineer and a Certified Building Systems Diagnostics Technician.

Energy-saving renovations reduced annual utility costs for air conditioning heat sources by 500 million yen (60 percent)

Collaboration with Japan's Leading Experts

Implementing Energy-Saving Renovations Without Interrupting Business Operations

Achieved a 56% reduction in energy consumption in the first year!

Kyosuke Takano

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