Evaluation of Air Conditioning Maintenance Costs of the Faculty of Engineering, Khon Kaen University, to Provide as Criteria for Decision-Making in Estimating the Budget for Replacement Procurement

Abstract

The Faculty of Engineering, Khon Kaen University, has a large number of air conditioning units with high acquisition and maintenance costs, yet past replacement decisions were based mainly on asset age and physical condition, without a systematic analysis of life-cycle cost data. This research therefore aimed to analyze the accumulated maintenance costs of air conditioning units and to estimate the replacement budget for the Faculty of Engineering, Khon Kaen University, by applying public asset management concepts together with Life Cycle Cost (LCC) analysis and the Repair-to-Replacement Ratio (R/R Ratio) as decision-making criteria. The methodology employed secondary data analysis using asset databases, maintenance histories, and market price data. Descriptive statistics were used to calculate the repair-to-replacement ratio for each unit, and assets were classified into three categories: less than 30% “Retain”, 30–60% “Monitor”, and greater than 60% “Replace”. Scenario analysis was also conducted to compare full replacement and phased replacement strategies. The results showed that, among 1,075 air conditioning units, the average R/R Ratio was approximately 9.5%, with units classified as 90.2% “Retain”, 6.6% “Monitor”, and 3.2% “Replace”. Replacing only the units requiring immediate action would require a budget of approximately 1.06 million baht, and including the “Monitor” group would require a total of approximately 4.53 million baht. These findings provide a set of financial decision-making criteria for budgeting and asset replacement that can reduce inefficient maintenance expenditures and long-term budget burdens, support transparent and accountable procurement processes, strengthen data-driven asset management systems, and serve as a replicable model for asset management within higher education institutions.