Economic evaluation of a district cooling system incorporating thermal storage.

Abstract

The following report investigates district cooling systems. This form of technology provides an

alternative means of providing cooling. In a traditional cooling system each building would

include cooling equipment to serve only that building. District cooling differs in that water is

chilled at one location and pumped to two or more buildings. District cooling has many benefits

over traditional cooling systems. This report, however, aims to determine the economic benefits

(if any) of district cooling systems.

The location chosen as a model for this study was the University of Natal (Durban) campus.

This campus currently operates a district cooling system serving six buildings. This study is

hypothetical in nature, as the cooling system is already finalized and operational. The aim of this

dissertation is to answer the question of which would be the more attractive alternative if the

University were in a position of having to install a completely cooling system.

One of the most important steps in this process is the calculation of cooling loads. The cooling

load was estimated for each of the buildings associated with the district cooling system. The

LOADEST software package was used to derive these cooling loads. The accuracy of

LOADEST software was also validated in this study.

The bulk of this report is composed of the preliminary work required to obtain capital and

operating costs for cooling systems, including validation of cooling load calculation software. It

was felt that this prelimiinary work justified inclusion in the final report to provide accurate

representation of the steps taken before any economic evaluation could be reached.

The capital and operating costs of the district cooling system and a more traditional system were

compared. It was found that the district cooling system reduces operating costs significantly,

although it's capital cost is higher than the traditional system against which it was compared.