Maintenance cost of chiller plants in Hong Kong

Abstract

Research findings about maintenance costs of chiller plants - a ubiquitous installation in large buildings, are rare. The study reported in this paper was conducted through inspection of 40 maintenance contracts, their associated monthly service reports and payment records, and interviews with the contract administrators. Routine maintenance cost was found to dominate among the maintenance resources. Repair maintenance work accounts for a less, but significant portion. The cost incurred for emergency maintenance work is minimal and condition analysis is seldom applied. Large chiller plants, by virtue of their scale, can economise on their maintenance cost. Total maintenance cost varies with plant age following a 'bell-shape' pattern, with relatively less expenditure for new and old plants whereas that incurred for middle-aged plants spreads over a wide range. Factors that potentially affect the cost relation between preventive maintenance and corrective maintenance have been identified. Apart from investigating their effects clearer, future work is needed to explore how to improve the practice of recording plant faults, which are crucial performance data to reflect whether the costs spent on maintenance are value-for-money. Practical application: The study has revealed the significance of various maintenance cost elements and the empirical cost relation between preventive maintenance and corrective maintenance. The effects of plant capacity, age of plant, operation period and heat rejection method on maintenance cost have also been analysed. Understanding the influence of these factors can help practitioners prepare maintenance budgets and perform benchmarking exercises. Besides, the lack of proper record of plant faults, as identified, is a barrier, which needs to be overcome before evaluating the value of maintenance service.