Motivation

The motivation to tackle the COOL-QUARTER-PLUS project is based on the constant and unstoppable increase in the cooling requirements of the global building stock. The rapid growth of cities and their densification and sealing are combining with the effects of climate change to become massive drivers of this development. Passive urban and building-related cooling concepts are integral components of solution approaches, but are now also reaching their limits in Central Europe and urban heat islands are spreading. The massive increase in the sale of decentralised cooling units is a consequence of this development. However, these often have poor efficiency and high noise levels, cause uncomfortable draughts and are increasingly becoming a problem for the appearance of building façades. The associated rapid rise in energy consumption is diametrically opposed to the necessary reduction in greenhouse gas emissions and the implementation of energy-plus neighbourhoods.

Goal

The aim of COOL-QUARTER-PLUS is to counter the current trend towards inefficient individual appliances with coordinated cooling concepts at neighbourhood level. The focus here is on office and research districts, as district-centred measures are more likely to be implemented in these districts than in heterogeneous residential or mixed districts due to the ownership structure and central operational management.

Method

The method uses data from a real research neighbourhood to set up the simulation model of a reference neighbourhood and validate it in terms of energy technology. Based on this, decentralised and district-centred cooling concepts are developed and mapped in dynamic simulation models. Individual cooling concepts are also assessed using life cycle assessment (LCA) and cycle costing (LCC).

Results

The results show that the networking of PV systems in the reference neighbourhood generates clear advantages over individual building-related systems. Different available installation areas and different cooling requirements can be balanced out between the individual buildings, which means that a higher proportion of the generated electrical energy can be used in the neighbourhood. The thermal coupling of cooling units to a neighbourhood cooling network must be considered in a more differentiated way in this context. Cooling networks connecting buildings cause both financial and ecological costs as well as thermal losses during operation. Whether this expenditure is worthwhile from an energy, economic and ecological point of view depends on the respective configuration and mode of operation. The most energy-efficient energy systems are those that combine the two functions of cooling and heating and operate them interchangeably as part of an overall concept.

Another aspect of the project is to design the cooling operation to be as demand-orientated as possible. To this end, machine learning models are being developed to predict the energy requirements and thermal behaviour of rooms. Based on this, a user-centred optimisation is implemented that minimises energy consumption and at the same time actively involves the users in order to take their comfort needs into account in a targeted manner.

Project management

Institute of Thermal Engineering / Graz University of Technology

Project or cooperation partners

• Institute of Software Technology, TU Graz
• Institute of Electrical Power Systems, TU Graz
• Institute of Technology and Testing of Construction Materials
• EQUA Solutions AG
• simulation services technical solutions GmbH
• TB-Starchel Ingenieurbüro GmbH

Institute of Thermal Engineering
Graz University of Technology
Dr. Thomas Mach
Inffeldgasse 25b
A-8010 Graz
Tel.: +43 (316) 873 7814
E-mail: thomas.mach@tugraz.at
Web: www.iwt.tugraz.at