1. Thermal Management Solutions from APW President Systems

2. … the story so far In the beginning power dissipation
levels in Cabinets were low ……………….
With the advent of rack mount servers, the power dissipations increased ………..
Now, with use of 1U Servers becoming
widespread, these levels are set to cross.
Floor space in Data Centres is expensive.
The trend is to pack as many servers in
one cabinet as possible
But conventional cooling methods are inadequate when the “ceiling” is reached
typically watts
typically watts
6 KW in a 42U cabinet!
$ 20,000.00/sq.ft
3.6 KW in a cabinet

3. So what do we do? We start with the basics!
Fundamentals of Heat Transfer…. revisited
What happens inside Electronic Equipment
What happens inside Cabinets containing electronic equipment
Typical arrangements in Datacentres and Computer rooms
Introducing the CoolRack from President – and how it works
The CoolRack – a real life solution
What the CoolRack solution will do for you
A summary of benefits
More COOLING options from President

4. General Cooling Methods
At todays power levels
radiation and conduction methods are inadequate. Heat has to be “convected”
away by moving fresh
air past the heat-emitting devices
All electrical components
and devices emit heat.
At low energy levels radiation is a good enough way to dissipate this heat
At higher dissipation
levels, radiation alone
will not suffice and heat
has to be conducted
away by using heatsinks 1 2 3

5. Current Trends Individual fans for critical devices Power Dissipation
Todays high performance Rack-Mount Servers consume as much as 300 Watts of power in a 1U high format. This power is dissipated as heat within the cabinet
1U Server
2U Server
3U Server
A 1U Server
uncovered
Current Trends
Power Dissipation
Packing Density
DC fans to evacuate the heat
Individual fans for critical devices
Prevention of hot spots forming
due to still air

6. Internal view showing devices with heat sinks for conduction and DC fans set up to create strong air currents from the front of the equipment towards the rear.

8. In general, professional grade equipment have adequate cooling provisions designed into them so that they are able perform normally to their published specifications given the required ambient conditions…… provided those required ambient conditions are maintained unimpaired. Equipment stacked inside a Cabinet encounter a very different environment from the free- standing equipment in an air-conditioned room.

9. Conventional cooling methods for computer equipment in cabinets … generally adopted arrangements
Light thermal loads
When heat dissipation is 300 watts or less, no special arrangements for airflow are needed. The metal skin of the cabinet provides sufficient heat transfer through radiation.

10. Exhaust fans
cause cabinet
air to flow to
the top
The warmed up air flows out from the top after collecting heat from the equipment inside
Moderate thermal loads
Air is drawn into the cabinets through vents at the sides
Note: This arrangement works fine as long as cabinets are not placed
side-by-side, as this will prevent airflow into the cabinets
When heat loads are between 300 – 600 watts conventional arrangements for dissipating the heat by means of air convection are adequate.

11. Heavy thermal loads
In the case of rack-mounted Servers that have their air intakes in the front, or rows of cabinets placed side-by-side, air flow MUST be from the front to the rear of the cabinets
When the heat load inside cabinets with rack- mounted Servers exceeds 1000 watts, then strong airflow has to be set up in the front-to-back direction. But these conventional methods have limitations

12. The type of arrangements for cooling of equipment inside
cabinets just seen is the conventional approach. These worked fine till now when heat loads were fairly light. But these methods have severe limitations in todays situation.
Conventional cooling methods are 30 years old
Conventional designs compromise equipment reliability
Conventional cooling systems are expensive to build
Conventional design is expensive to operate
here’s why……….

13. In many Computer Centres it is common to have the AC Inlet and Return ducts running along the top of the room. This results in airflow patterns that are far from ideal for the equipment inside the Cabinets.
Incoming air at
16-18 C
Return air temp.is
25-28 C at best
Inlet air will take the line of least resistance.A large proportion will flow into the return duct
Air exiting the cabinets
Will be at C
Air flowing down is diluted by the room air.Temp.will rise to C by the time it is drawn in at the bottom of the cabinets

14. The newer computer facilities may have both false ceilings and raised plenums with the inlet AC ducts below the raised floors while the return air ducts are above. This leads to more effective equipment cooling
Air temp
at top of
will be C
Most incoming air still
flows into the room.Its
temp.rises to C
Inlet air at C
Is drawn into the
Cabinets at the bottom
Air inflow at C

15. Same room showing cabinets positioned over the AC inlet
Return air ducts
Incoming air at deg. C

16. Airflow patterns and temperatures in a typical Computer centre
“Delta T” is 10 deg typically

17. Possibilities with the “CoolRack” arrangement
A “ Delta T” of as
much as 20 deg is
possible

18. How does the CoolRack concept work ?
Conventional Datacentre set-up
With a delta T of degC and 3.6 kilowatts power dissipation
Airflow required = 569 CFM
With the CoolRack set-up
And a delta T of 20 degC, with 3.6 kilowatts power dissipation
Airflow required = 284 CFM
Thus the CoolRack method uses half the airflow !
Half the airflow means a 50% reduction in Air Handling capacity
Each AC unit transfers twice as much heat energy
Reducing the airflow by half means 50% fewer fans motors

19. The CoolRack approach reduces the cost to cool a data centre by 14%
In a typical data centre, fan energy accounts for 28% of the total cooling plant
energy
The CoolRack approach reduces the cost to cool a data centre by 14%
It also reduces the initial investment outlays because …..
Half as many AC units are needed, and associated ducting
Reduced cooling plant size (due to less fan motor heat)
Reduced emergency power requirements
Leading to a net saving on initial investments of 5% or more

20. Introducing the CoolRack --- a configured solution for your thermal problems

21. CoolRack – an internal view

22. Presidents CoolRack
A side view showing the
Internal airflow paths

23. Same views - but showing airflow arrangements

24. Slides giving the efficiencies and savings to be gained from the Cool Rack approach and other quantitative data

25. Summary of benefits

26. Presidents CoolRack - the reality

29. Inside the CoolRack: Accessories include vertical Cable Managers and an AC Power Channel with high- reliability universal IEC Sockets. Note also the provisions for Cable entry

31. Here’s what has been happening
39 Servers in 42U of
Cabinet space!

32. Fans shown mounted directly on the
Rear Door so as to create a front-to-
back air flow

34. Benefits of the CoolRack solution
Ability to house more Servers in a Cabinet ……. Upto 42 in a 42U cabinet
Equipment runs cooler- therefore more reliability…… MTBF is increased
Optimal use of the AC plant capacity …………… less capacity needed
Initial costs for Air Conditioning plant reduced …… upto 7% savings
Running costs for electrical energy reduced ………. upto 14%

35. What will the CoolRack do for you ?
Provide the means for utilizing your air conditioning capacity more efficiently
More efficient use of AC capacity means that you need use less cooling power
Net Result
Increased MTBF
Savings in investment and operating costs