239 Xuan Thuy, Cau Giay
|Type of Building:||Office Building|
|New / Refurbished:||Refurbished|
|Year of construction:||1995|
|Gross Floor Area:||10000 sq.m|
HITC has been in operation since 1995 and became the first Class A building for office rentals in Hanoi. HITC was also the first Office Building to receive the ISO Certificate for Quality Management. There were more than 10 energy efficiency measures were implemented since 1997 but most measures were carried out during 2006 to 2009 creating significant energy saving of 410,000 kWh or 14% energy reduction. Most of measures are unique and were developed and installed by HITC engineers in accordance with the building conditions, thus allowing reasonable price but achieving higher level of energy efficiency for the building.
Third Party verified: No
Source of information: HITC Ltd.
Method of data collection: interview with service manager and data collection via email
+84 4 38 341 326
+84 913 208 060
• Cladding for the building includes vitreous tile (low moisture absorption) and reflective glazing which can reflect up to 90% of Infrared (IR) radiation.
• Many windows are installed with insulation film to further reduce the heat absorption.
Most major functional areas are arranged near the glazed walls to maximize natural light collection. Calculations show that up to 45% of the floor area are lit by daylight.
The HVAC system is composed of Packaged Air Conditioners with Water Cooled Condensers. The schematic diagram for the system prior to upgrade is as below:
Prior to upgrade, condensers of package units located at each floor (4 units per floor) were cooled by 2 cooling towers. Originally, the design of the system was that cooling tower 1 supplied cooled water from floor 3 to floor 8, and cooling tower 2 served floor 1 and 2. With such a configuration, the system had to run at full power regardless of actual cooling requirements, resulting in a major inefficiency in power consumption. From 2003 to 2009, the building applied the following solutions to help optimize the system in accordance with actual cooling requirements:
1. Connection of two separate pipelines for the cooling towers:
• Prior to the upgrade, the piping system for the two cooling towers was separated. The two pipelines were joined so that one cooling tower can run for all floors or/and one pump can run for any cooling tower during low demand for cooling.
• Installation of new valves to local package units: New valves were installed to the local package units at each floor to block off the distribution of cool water to floors with package units not working. This solution helps optimize the performance of the pumps.
2. Installation of Variable Speed Drive (VSD) motors for the 45kW pump:
There are 2 pumps with capacity of 45kW and 30kW respectively for the 2 cooling towers. A VSD motor was installed for the 45kW pump, allowing for a flexible configuration of the pumps. When the required motor power is smaller than 35kW, only the 45kW pump is working. And when it goes up to more than any of the two capacities, the smaller pump will run at full power and the larger at actually requirement. With such flexible configuration, the 2 pumps can run at different power from 0 to 80 kW to avoid unnecessary capacity.
3. Usage of new fan blade, different pulleys and motor systems for the cooling tower:
The load of the cooling tower was reduced by 3 strategies:
• The original fan blade for the cooling tower was replaced by a new one with adjustable angle of incidence. It helps increase the wind velocity so that the output temperature for cooling water can be significantly reduced
• Different pulleys were used to demultiply the speed
• Different motor capacity were used so that the fan can be operated at lower capacity during cold winter days, reducing the power consumption
4. Installation of the Central Air Temperature Control System:
A software was installed together with the existing thermostat system to control and minimize temperature fluctuation and allow for reduced temperature increment (from ± 1.50C to ± 0.10C).
5. Replacement of 150 magnetic ballasts of 15 W by electronic ones of 2.5 W
Magnetic ballasts consume from 5-10W itself compared to electronic ballasts which consume as little as 2-4W. All of the magnetic ballasts were replaced by electronic ballasts for fluorescent lamps to have more energy efficient lighting.
For electricity equipment:
6. Installation of capacitors for the building electrical system
Capacitors were installed for the whole building electrical system to smooth the output of power supplies. The power factor Cos Phi was raised from 0.85 to 0.99 and was translated to a saving of 16% for the overall electrical bills.
7. Installation of auto sensors for escalators
Originally, escalators were designed to run with 22kW capacity for 12 hourscontinuously. HITC developed and installed auto sensor devices for the 2 escalators for those to run only when there is traffic and stand by when there is no traffic.
Commitment to energy efficiency policies:
General Director of HITC, Mr. Preben Hjortlund affirms: “We provide quality for our clients and their satisfaction is our brand name”. Using energy efficient is one of the quality factors of HITC which can be seen clearly in its policy on energy management since the very first days of its operation. This policy has been maintained and consolidated which helps HITC in finding areas of inefficient energy consuming for improvement. HITC commits to maintain and improve its energy saving policy in order to become one of the most energy efficient Buildings in Hanoi.
Digital time control central system:
A control central system was developed and put into operation to program waste water pump, lamps, etc equipment to work only during normal or off-peak hours or to turn off or stand by when usage is not required. Hardware for the control system was supplied by Siemens, while software for the system was designed by partners in Vietnam following HITC’s order.
Schedules for monthly, quarterly, annually maintenance are set for every equipment/device. Preventative maintenance proves to be very effective at HITC to optimise equipment performance and increase lifespan.