MHI Thermal Systems Unveils Waste Heat Technology: ETI-W Centrifugal Heat Pump

Mitsubishi Heavy Industries Thermal Systems (MHI Thermal Systems) launched the newly developed ETI-W centrifugal heat pump for the Japanese market, which effectively uses waste heat generated during factory production processes. It achieves a maximum hot water supply temperature of 90 ℃ and a large capacity of up to 640 kW, suitable for high-temperature applications that were previously handled by conventional boilers.

The new ETI-W centrifugal heat pump will be used across various applications, including:

• Electronics
• Automotive
• Food
• Chemical
• Pharmaceutical
• Heating and hot water supply in commercial facilities

The pump’s coefficient of performance is 4.01 when supplying hot water temperature of 90 ℃, and it’s capable of handling large-scale industrial capacities equivalent to a 1-ton boiler with 640-kW capacity. It is equipped with centrifugal compressors—also utilized on MHI’s centrifugal chillers—that are designed for refrigerant characteristics and high compression ratios.

ETI-W centrifugal heat pump | Image Credit: MHI Thermal Systems

The technology achieves high performance and a small footprint by using an inverter starter panel within the primary unit and a shell-and-tube heat exchanger. On the environmental side, it uses a non-fluorocarbon refrigerant—HFO-1233zd(E)—with a global warming potential of 1 and does not deplete the ozone layer.

MHI’s EC-8

MHI Thermal Systems launched an updated version of its Ene-Conductor Heat Source Control System. The new EC-8 model, arriving in spring 2025, features advanced control capabilities for up to eight centrifugal chillers and peripheral equipment, such as chilled water pumps, cooling water pumps, and cooling towers. Its energy-saving control functions include:

• Controlling the number of centrifugal chillers
• Controlling the variable flow rate of chilled water
• Cooling water

The EC-8 model supports both the individual pump system and the multiple pump system widely used in large-scale facilities built across Southeast Asia and the Middle East. It uses the BACnet protocol and Modbus to enable real-time communication and information exchange between machines and sensors, improving response time. The system contains fewer signal cables, simplifying construction management.

The EC-8 control system automatically selects the air conditioning system’s optimal operating point, cutting power consumption by up to approximately 26% and improving overall energy efficiency. Its repeatable system design and installation workload can be minimized, enabling simple integration at existing and upcoming facilities. According to MHI Thermal Systems, the EC-8 can be installed without modifying the current facility for additional energy savings.

Thermal Energy Storage

In late November 2024, Aisan Industry placed an order with MHI Thermal Systems for a large-scale Aquifer Thermal Energy Storage (ATES) system to provide air conditioning at its Anjo Plant. The ETI-Z25.HP centrifugal chiller has a cooling capacity of 234 refrigeration tons (RT)—823 kW per unit—and supplies both hot and cold water. This ATES implementation project will begin in winter 2025 and represents MHI Thermal Systems’ first practical application outside the Kansai region.

Using high-efficiency centrifugal chillers and control technologies, such as automatic switching of optimal operating modes, may reduce yearly CO₂ emissions by approximately 50%. The system uses HFO-1233zd refrigerant, which has the lowest global warming potential to minimize its environmental impact. Overall, the system offers energy-saving performance, optimal control technology, and improved operational performance.