Measurements of individual chiller systems compared to district cooling solutions

Panel: 6. Innovations in buildings and appliances

This is a peer-reviewed paper.

Authors:
Johannes Jungbauer, Euroheat & Power, Belgium
Pär Dalin, Capital Cooling, Sweden
David Serrano Garcia, Districlima, Spain
Damien Terouanne, Climespace, France
Alexander Wallisch, Fernwärme Wien, Austria
Niko Wirgentius, Helsinki Energy, Finland

Abstract

Today 40% of commercial and institutional buildings in Europe have cooling systems and energy demand is set to grow substantially. The energy demand related to cooling/air-conditioning purposes is often underestimated or not known by customers (and political decision makers,) as the electricity used for chillers is hidden in the building’s total electricity bill and the delivered cooling energy is not even measured.

The main barrier for the improvement of this situation is the fact that customers rely on chiller performance coefficients to estimate their consumption, which are provided by manufacturers. The first part of the paper shows that these coefficients were not reached in the actual measurements of individual chiller systems of buildings in France, Finland and Sweden.

Individual installations operate in some cases only at a third of the efficiency indicated by manufacturers. Results collected from more than a year of measurements show that average Energy efficiency ratio (EER) values measured varied between 0.84 and 2.87 in Paris and Finland. The EER in Gothenburg was 2.8. The planed figures for this plants were EER 4 and higher.

The main finding is that there is a wide gap between theoretical EER values and real-life performances of chiller systems and that the results were nearly the same in all cities.

In a second step the paper presents measurement of the primary energy factor (PEF) of District Cooling systems, which can be regarded as a sustainable alternative to conventional cooling solutions.

The method of calculation the PEF of District Cooling systems is explained and the different results presented. Also for District Cooling system, depending on local preconditions, the calculated values differ from system to system.

In a last step the paper compares the measured EER values of the individual chiller systems, which are converted into PEF with those of existing DC networks throughout Europe.