Retrofit

Building Owner

Hongkong Land Limited

Building/Project Name

Chater House

Systems

HVAC - Waterside Air Conditioning System
Building Automation /Management System

Building Types

Commercial - Office

Description of the building:

Chater House is at the hub of Hongkong Land's portfolio in Central, with telecommunications, electrical and mechanical features designed for the specific needs of investment banking and financial services.
One of the four iconic buildings under LANDMARK, representing the epitome of top-tier luxury shopping and lifestyle experiences.

Retrofitted initiative:

Centralised chilled water plant:

Replace 5 of the existing 12 air-cooled chillers into 3 water-cooled chillers. The water-cooled chillers were installed and connected with the remaining air-cooled chillers. Cooling towers were installed on the roof for heat rejection. A variable flow, decoupled chilled water system is adopted.
Chilled water plant control:

Converting from manual operation to automatic plant operation, a new BMS system is installed with energy optimisation strategies for better control and equipment monitoring, including the upfeed pumps, condensing water pumps, cooling towers, make-up tank, condensing water tank and water-cool chillers. The air-cooled chillers and new water-cooled chillers work seamlessly to meet the building cooling load in an energy efficient manner.

Observed benefits other than energy saving:

Reduced operator resources in plant operations with adoption of automatic chiller plant operation.
Larger overall cooling capacity (5 existing 300Ton ACC replaced with 3 new 750Ton WCC).
New chillers and chilled water pipes now housed indoor are better protected and less prone to outdoor damages.
Lower noise level since outdoor air-cooled chillers are commonly known to produce higher noise levels via chiller condenser fans.
Less vibration.
Enhanced reliability of chilled water supply with the presence of both water-cooled chillers and air-cooled chillers.
Longer service life of water-cooled centrifugal chillers than air-cooled screw chillers.

General observations of the retrofitting project:

Space utilisation is the key since extra space is needed to install cooling towers and condensing water pumps for water cooled systems.
Plan for upfeeding water to make up the water loss during operation of cooling towers.
Equipment delivery is another critical challenge. Unlike air cooled chillers which are mostly modular design, larger capacity water cooled chillers tend to have a long bundle of evaporator and condenser.
Energy saving is significant.

Other information:

Cost		Saving
Total cost:	Around HKD 23 million (2010)	Savings/year breakdown:	>45% total energy consumption saving >3.35 MWh saving per year Saving in parts replacement and service cost of air-cooled chillers and saving in manpower resources in plant operation >HKD 2 million
Cost breakdown:	Mechanical and Electrical work over HKD 13 million Chiller Supply over HKD 10 million
		Payback:	(HKD 23 million – HKD 2 million) / HKD 4.36 million = 4.82 years
Name of the consultant and contractor
Consultant: WSP (Hong Kong) Ltd. Contractor: The Jardine Engineering Corp., Ltd.