The Metropolitan building (235 Dong Khoi, District 1, Ho Chi Minh City), with the main function of an office for rent, was built in May 1996. Since 2004, seeing the importance of saving electricity in terms of economy as well as environment, the Directorate of the building has invested in renovating energy using equipment to save costs and meet development demand. With investment solutions, the annual power consumption of the building has been reduced by about 11.9%.

Joining the Energy Efficiency Building Competition IV/2010 organized by Ho Chi Minh city Energy Efficiency Center under the leadership of the Ministry of Construction and the Ministry of Industry and Trade, The Metropolitan’s Directorate hopes that the solutions successfully applied in the building will actively contribute to promoting the implementation of energy conservation and environmental protection in constructions in Vietnam.

An advantage of the Metropolitan is being located on the crossroads of Dong Khoi and Nguyen Du, the two most beautiful streets of District 1, HCM city. With that advantage, all sides of the building are installed with glasses to create a modern architecture. In the two fronts, the glass windows are designed as 2-storey arched door frames, creating a harmonious architecture with the ancient architectural style of the Notre Dame Cathedral. The glass window system has also significantly reduced power consumption for lighting of the building by making the most of natural light.

Although being built in 1996, The Metropolitan is a result of the joint venture cooperation between Binh Minh Construction One-Member Co., Ltd and Saigon Metropolitan Limited (in British Virgin Island), a foreign partner, so the construction was completed with the highest quality. The exterior of the building uses granite which can reduce heat radiation to the building as well as minimize heat transfer through the walls. According to designers, wall temperature inside the building when using stones will be 3-5oC lower than when using regular paint.

Besides, the light yellow paint covering the walls of the building also helps save energy because this is one of the colors which have relatively low solar radiation absorption coefficient compared to other colors, just about 0.58. In the upper floors, the building uses heat resistant paint, suitable with the tropical environment of Vietnam.

Joining the competition with the type of renovated building, the Metropolitan mostly saves power through replacing and renovating available facilities and equipment or making the best of existing advantages such as natural light and wind. For example, with the chiller system, the cold water flow was previously controlled by TYA, causing high hindrance of pipelines, making the pump increase the capacity. Installing inverters to control water temperature, the building has saved 528,000 kwh per year      

Also with the chiller system, when the outdoor temperature is low (in the morning & evening) or when the number of employees as well as electrical devices reduces at noon, the central air conditioning system still operates with two 500Ton chillers, leading to energy waste since the capacity excesses the demand. To deal with that problem, technical staff of the building have operated only one 500T chiller or one 500T chiller    and one 250T chiller at low load hours which are from 7am to 8am, from 11am to 13pm and from 4 pm to 6 pm. That way, each year, the building has saved over 79 thousand Kwh.

Compared with T10 lamps used before, the current 1.2 m and 0.6 m T8 lamp system reduces 20% of electricity consumption, equivalent to 19,000 kWh per year. In addition, for aesthetic lighting of the building, all decorative lights use 14W compact bulbs. These bulbs can save 735 kwh per year compared with previous halogen lamps.

In particular, at The Metropolitan, the work of management has always been considered to bring high efficiency. Currently, the building is using a device management software that allows managers to observe operating condition in areas such as chiller, elevator ... to timely apply adjustment measures.

Besides, Board of Directors has also decided to replace some CRT screens of computers and televisions by compact, modern and economical LCD screens. Computers and office machines are set in stand by mode or energy saver mode to save power. At the same time, the managers often propagate and remind the staff in the building to use electrical devices reasonablly to avoid energy waste.

Currently, the "Energy Efficiency Building Competition 2010" has gone through the preliminary round with 35 buildings which are eligible to go to the next round. In particular, The Metropolitan has the honor to represent "Green architecture" of Ho Chi Minh City to continue to participate in the finals which will take place in Hanoi.

Minh Duc