A Cost Effective, Energy Efficient Solution For The Heat Of The Tropics


Graha Kencana Building
in Jakarta, Indonesia

With a hot and humid tropical climate, cooling
is one of Indonesia’s largest energy demands.
On average, 50% to 60% of a commercial
building’s electricity expenditure is used for
air conditioning. 1
The Graha Kencana office tower is a great
example of the move towards greener buildings.
By replacing its outdated air conditioning with
Hitachi’s SET FREE Variable Refrigerant Flow
system, the Graha Kencana tower has made
significant energy savings, and has benefited
from numerous other positive effects.

Key outcomes
✓✓ Maximized Cost Efficiency — VRF has enabled substantial savings
on cost by reducing energy consumption and the frequency of
maintenance. Easy centralized control from the building manager’s
office creates more opportunities for energy-saving optimization.
✓✓ Environmental Performance — Graha Kencana is more
environmentally-friendly, using less energy to fulfill the same demand
for cooling. Additionally, the building is now using R410A instead of
R22 refrigerant, thus eliminating ozone-depleting emissions.
✓✓ Uncompromised Comfort — Air conditioning is now exceptionally
quiet, resulting in higher satisfaction amongst building occupants.
A progressive installation ensured minimal disruption to tenants.

Issues to be addressed
With an average annual temperature of 27.6°C2 , cooling is required throughout the year in the
Jakarta area. Previously, the Graha Kencana building was using aging water-cooled packaged
units, which required dedicated air handling unit (AHU) rooms on each floor. This system was
problematic for a number of reasons:
• Poor energy efficiency, resulting in higher operations costs.
• Constant maintenance, spare parts were difficult to procure, and the water piping needed
regular leak repairs and cleaning.
• Reliance on ozone-depleting R22 refrigerant, which has been increasing in price as it is being
phased out in accordance with the Montreal Protocol.
• Disruptive noise, as the AHU rooms were on each floor, which disturbed adjacent occupants.

Key stakeholder requirements
The Building Owner — required a reliable and durable system future-proofed to perform
over the course of many years. Switching from water-cooled units to a VRF system induced
significant non-negligible retrofitting, but the high energy efficiency of Hitachi VRF will allow
the Graha Kencana to save on operational and maintenance costs well into the future.

Our solution
A combination of Side-Flow and Top-Flow compact outdoor units from the SET FREE
range was selected for optimum performance and efficiency.
Top-Flow outdoor units were installed on the roof of the building, delivering air conditioning
to major parts of the building. Side-Flow units were installed on the 2nd floor balcony, which
connect to the ground floor indoor units. This flexible combination leverages the building
space to optimize the refrigerant piping layout, limiting the need for retrofitting work. For
simplified and discreet integration, 46 of the 51 indoor units are ducted concealed types with
high static pressure up to 180Pa.
For the Graha Kencana building, SET FREE system provides:
• Energy Efficiency — By modulating the compressor speed (inverter) and refrigerant flow
in each outdoor unit, the system can adapt to fluctuations in energy demands (such as in
meeting rooms which are busy at certain times of day), minimizing any unnecessary usage.
• Reliability — Hitachi’s original Scroll Compressors are synonymous with superior
reliability. As a leading pioneer of Scroll Technology since 1983, our experience and
expertise in manufacturing ensures excellent quality and durability.
• Outdoor Installation — The use of outdoor units on the roof and balcony eliminated the
need for AHU rooms on each floor, freeing up space for other applications. Additionally,
the retrofitting work was done progressively over the weekends, minimizing disruption to
building occupants during installation.
• Quiet Indoor Units — Noisy AHU rooms have been replaced with discreet ducted units,
which produce noise levels as low as 42dB(A).