Dantherm Presentation in INTELEC 2015 conference

1. © Dantherm A/S
The Effect of Free Cooling on Reducing Total
Energy Consumption for Telecommunication
Base Stations
Ehsan B. Haghighi
PhD, Thermal Specialist
Dantherm Cooling AB, Sweden
INTELEC 2015, Osaka, Japan

2. © Dantherm A/STitle of presentation DD/MM/YY Author Confidentiality level
• I have the best power system!
• I have the best battery technology!
• I have the most optimum power conversion
technique!
• I have the best recovery and mitigation system!
• I have the highest quality ICT equipment!
• But I still need “something” else to guarantee I
am running my system!
What do I need to run a telecommunication
base station (BTS)!?

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Introduction
Simplified energy model
A case study
Results
Conclusion
Content

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Typical air conditioning system and total
energy consumption in a BTS

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Re-designing building envelopes
Improving air conditioning systems
Optimizing indoor air flow distribution
Adding monitoring and controlling units
Improving energy management and using renewable energy
sources
and ...
Sharing the cooling load between air conditioning and free
cooling systems
Energy reduction strategies

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WHAT IS FREE COOLING?

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How does it work…

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SHARING FREE COOLING AND
AIR CONDITIONING SYSTEMS!

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How does it work…

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A simplified energy model
INFSOLENVITCOOL QQQQQ 
)( ioENV TTUAQ 
“HVAC engineer's handbook” and
“ASHRAE Handbook Fundamentals”
)( ioPINF TTnVCQ  

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Controlling strategy
if TSET<=TO => Air Conditioning
if TSET>TO => Free Cooling
Assumption: the effect of mixing the fresh air with the warm indoor air
already inside the envelope is ignored

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A case study
L=4 m, W=3 m, and H=2.8 m
QIT=4 kW and U=1.5 W/m2K
number of air changes = 1.5 per hour
TSET=25 °C

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Locations
Copenhagen (Denmark)
San Francisco (USA)
Shanghai (China)
Dubai (UEA)
Weather data: ASHRAE (for 0.4% cumulative frequency of occurrence)

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Results: Copenhagen (Denmark)

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Results: San Francisco (USA)

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Results: Shanghai (China)

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Results: Dubai (UEA)

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Results: the effect of indoor set temperature

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Results: the effect of building materials

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NOT ONLY DIRECT FREE COOLING,
BUT ALSO INDIRECT FREE COOLING
SUCH AS:
• HEAT EXCHANGERS
• THERMOSIPHONS

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How does it work…

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How does it work…

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New cooling solutions to improve energy
management in BTSs are necessary.
Fresh outdoor air (either direct: a fan or
blower, or indirect: air-to-air or
thermosiphon heat exchangers) to cool IT
equipment is efficient and cost-reducing in
many places all over the world.
By increasing the indoor set point
temperature the share of free cooling and
savings can be increased.
Conclusion

25. © Dantherm A/S
Ehsan B. Haghighi
PhD, Thermal Specialist
Dantherm Cooling AB, Sweden
https://www.dantherm.com
ebh@dantherm.com
Thanks a lot for your
attention!