Reversible heat pump for an office building in Arnulfstraße
Refurbishment, modernization and functional expansion of the cooling supply system
Project start
November 2024
Location / Location
Munich
Customer
aik Immobilien-Investmentgesellschaft mbH
Description
IBIG was commissioned with the planning, tendering and construction management of the technical trades. In the course of the work, the roof center received a completely renewed system technology. The centerpiece is an air-cooled and reversible heat pump, which provides both cooling and heating for part of the building. Thanks to the existing pipe network, operation can switch between heating and cooling functions (Change-Over).
As early as the planning phase, IBIG was able to demonstrate that this solution was not only technically but also economically convincing. The existing heating system was retained as a reserve to cover peak loads.
A separate cable network was installed for the IT infrastructure. In heating mode, it automatically disconnects from the office supply. Cooling then takes place via a recooler.
The result: A future-proofenergy-efficient overall solution that combines operational reliability, cost-effectiveness and sustainability.
Initial situation
The existing water-cooled chiller from 2002 with an output of around 200 kW was defective. The associated pumps and drycoolers were controlled via an MSR control cabinet whose taxing was discontinued due to age. Refurbishment was absolutely essential. At the same time, the available space was limited and there were high requirements for sound insulation.
Project objective
The primary aim of the project was to quickly recommission the cooling supply so that the newly rented office space from be able to cool the newly rented office space from mid-August 2025. In addition, a future-proof solution was to be developed that combines efficiency, sustainability and the requirements of the current F-Gas Regulation. At the same time, it was necessary to bring the overall system technology up to date. The focus here was on integrating a reversible heat pump. Another focus was on replacing all critical system components – in particular the chiller, pumps and I&C technology – to ensure long-term operational reliability.
Implementation
As part of the measures implemented, the chiller, which had previously been installed indoors, was replaced by a reversible heat pump installed outdoors. It was integrated into the existing pipe network via a buffer tank and a plate heat exchanger. In addition, a recooler with an output of around 10 kW was used to provide free cooling for the server rooms in winter.
The hydraulics were fundamentally overhauled to improve controllability and efficiency. Pumps, valves and sensors were renewed, and with the new MSR system (ISP-Klima), the system was equipped with modern control and monitoring technology.
Transfer boxes were installed on the supplied floors as an interface between the new ISP air conditioning system and the tenants’ own control systems. These indicate the current operating status of the system (heating or cooling, fault) by means of color signals and also provide the information via potential-free contacts. In this way, the tenants’ own systems in the office areas can be operated reliably.
