| Project | Chiller Replacement for MTR Central Computer Centre |
| Description | This is a project to replace the auxiliary air-cooled chillers for the central A/C system at MTRC’s Central Computer Centre. It specially required that sea water cooled chillers should be used and connected to the main cooling towers; and that modification work should be carried out on the existing cooling water system to suit both day and night modes. The project was the first of its kind in Hong Kong, and carried professional risks. M&P successfully completed this project in 1989, and the system is still in operation. |
| Highlight | Modification of Main A/C Equipment to Accommodate Auxiliary A/C System
In early 1980′s when the MTR stations were constructed, fresh water was not allowed to be used for commercial air-conditioning; and hence the MTR station at Central used sea-water cooling. But due to inadequate roof spaces, air-cooled auxiliary chillers were used for the computer centres, to save on the roof space. Unfortunately, being located near the sea-water cooling towers, these air-cooled chillers corroded quickly and required replacement after 7 years. |
| Highlight |
In 1988, in a similar case at Fairmont House, Admiralty air-cooled chillers were replaced with same. These new auxiliary chillers would again face serious corrosion, and suffer a short service life. In 1989, MTRC decided that a sustainable solution should be found for the Central MTR Station: by replacing the existing chillers with sea water-cooled chillers and using the main cooling towers to serve the auxiliary chillers (i.e. without separate auxiliary cooling towers to save on the roof space); and by modifying the main cooling water system to suit both the main and the auxiliary chillers. The decision was made even though such modification of major equipment had never been attempted in Hong Kong. M&P took up the challenge. The main cooling towers were 500TR each, and 5 times the capacity of auxiliary chiller. To prevent over-cooling and to improve on energy efficiency, M&P automated the cooling towers for variable load, and incorporated additional cooling water circuits to cope with the different external temperature conditions. These innovative designs solved the problem, and the system has worked successfully to this date. |