A feasibility study of investement a water cooled chiller system to replace an air cooled chiller system : a case study of a computer parts assembly plant
Abstract:
A chiller system is one of fundamental systems in most kind of industries and large
buildings. It usually consumes a majority of electrical expense. This study aims to reduce
the electrical expense of a computer parts assembly plant consumed by a chiller system.
The case study assembly plant currently uses an air cooled chiller system that consumes
a gross electric expense more than 13 millions bath/year and additionally 400,000
baht/year of maintenance cost. This study therefore has studied a feasibility of investment
to replace a current air cooled chiller system by a water cooled chiller system.
Engineering economy techniques are used to evaluate the proposed system in terms of
economy, payback period, and rate of return. Project management is used to create a
rough project plan of a system installation in case if the proposed alternative is accepted.
The economy analysis shows that an investment of 16,831,000 baht for a water cooled
chiller system, with 16 years of life-time, will consume 6,664,676 baht/year of electrical
expense and maintenance cost while the current system totally consumes 14,264,594
baht/year. In other word, the electrical expense will annually be saved 53% by the
proposed system. NPV of the current systems expense is 134,752,607 baht while the
proposed systems is 63,810,130 baht. The proposed system has 44.3% of IRR and
payback period is 2 years 3 months. Therefore, the proposed alternative is accepted. In
order to replace the current system by a water cooled chiller system, the project manager
will need 194 days to complete the project within the budget of 16,831,000 baht.