Reversible heat pump for an office building in Arnulfstraße
Refurbishment and upgrade of the cooling and heating system using reversible heat pump technology
Project start
November 2024
Location / Location
Munich
Customer
aik Immobilien-Investmentgesellschaft mbH
Description
IBIG was commissioned with the design, tendering and site supervision of the building services systems. As part of the project, the cooling plant in the rooftop plant room was completely renewed.
The new system is centred around an air-cooled reversible air-to-water heat pump, which provides both cooling and part of the building’s heating demand. Operation is based on the existing two-pipe change-over system.
During the design phase, IBIG demonstrated that this solution represents the optimal approach from both a technical and economic perspective. The existing heating system was retained for peak load coverage and as a backup.
A separate hydraulic circuit was implemented for IT cooling. In cooling mode, the system is supplied by the heat pump, while in winter operation, free cooling is provided via a dry cooler.
The result is a future-proof, energy-efficient system with high operational reliability and flexibility.
Initial situation
The existing water-cooled chiller from 2002, with a cooling capacity of approximately 200 kW, had failed. The associated pumps and dry cooler were controlled via a control cabinet with obsolete control components that were no longer available.
Replacement of the system was therefore unavoidable. In addition, space constraints and strict noise protection requirements had to be considered.
Project objective
The primary objective was to restore the cooling supply in time to ensure usability of the newly leased office spaces from August 2025 onwards.
Furthermore, a future-oriented system concept was to be developed that meets current requirements in terms of energy efficiency, sustainability and compliance with the EU F-Gas Regulation.
The aim of the project was to restore the cooling supply on time to ensure that the newly rented office space could be used from August 2025.
The focus was on integrating a reversible heat pump and renewing key system components – in particular the cooling generation, pump systems and building management system (BMS) – to ensure long-term, reliable and efficient operation.
The focus was on the integration of a reversible heat pump and the complete renewal of central system components – in particular the cooling generation, pump technology and I&C systems – to ensure long-term safe and efficient operation.
Implementation
As part of the project, the previously indoor-installed chiller was replaced with an outdoor-installed reversible air-to-water heat pump.
The system was hydraulically integrated into the existing network via a buffer tank and a plate heat exchanger for hydraulic separation.
A dedicated cooling circuit was implemented for the IT infrastructure. In addition, a dry cooler with a capacity of approximately 10 kW was installed to provide energy-efficient free cooling for the server rooms during winter operation.
The hydraulic system was completely redesigned and optimised in terms of controllability and energy efficiency. All pumps, valves and sensors were replaced.
A new building management system (BMS) was implemented, providing modern control and monitoring functionality.
To interface with tenant systems, transfer stations were installed on the served floors. These provide system status information (heating, cooling, fault) via visual indicators and potential-free contacts, ensuring reliable integration with tenant-side control systems.
Transfer stations were installed on the supplied floors to connect the tenants’ systems. These provide operating statuses such as heating, cooling and faults via color signals and potential-free contacts and enable secure integration into the respective tenant systems.
