COOLING

TECHNICAL VIEW

By : Ibrahem Batta

& emad shakhsheer

To Dr Alaa almasri

Parts

• LIQUID COOLING.

• AIR COOLING.

AIR COOLING.

HEAT SINKS

* Heat sinks are needed when the heat transfer to the ambient air directly from the top of the device is not sufficient to keep the semiconductor device within the allowable temperature range.

* heat sink was supplanted in higher power applications .

* increasing the thermal conductance of components and increasing the fin area exposed to the airflow is very important.

THERMAL INTERFACE MATERIALS

• TIM is essential when two or more solid surfaces are in the heat path.

• The air gaps created by multiple voids of "contacting" hard surfaces are simply too large a thermal barrier for even modest power applications.

• The first tactic in overcoming this barrier is to fill the voids and eliminate air by introducing a third material to the heat path that is fluidic and wets the surfaces.

Cont.

• An important property of any TIM is its thermal conductivity.

• grease and Elastomeric pads are used as TIM.

COOLING FANS AND BLOWERS

• Cooling fans and blowers are essential to systems

that produce a significant amount of heat like

computers and other electronic components.

• Different systems are

engineered to work with

specific types of fans.

• Cooling fans come in all

shapes and sizes.

as well as voltage,

airflow, and case size.

Difference Between Fans and Blowers

Axial fans:

• Create an air flow that is parallel to the axis of the fan blade.

• designed to work with systems that have low back air pressure and high rate air flow.

• less noise.

• Quite common and the most economical cooling solution.

• they are normally used in computers.

CONT.

Blowers :

• Send air on a perpendicular direction in relation

to its axis.

• Designed to work with systems that have high

impedance (i.e. high back pressure) and low rate air flow.

• It produce a more concentrated airflow

in a system, So they tend to generate

a significant amount of noise.

• they are used in Servers.

AC AND DC COOLING FANS

AC Fans DC FANs property

110v , 220v 5V, 12V, or 24V voltages

50 Hz , 60 Hz 0 frequency

Constant Variable Air Flow speed

high Low ( 60 percent less) Power consuming

Higher level

Lower level

Electro Magnetic

and

Radio Frequency

Interference

shorter longer Life

CONT.

• The difference in the cost between AC fan and DC fan is

negligible.

• When choosing fan for your applications, it is important

to look at the cooling requirements of the system and

applications, the fan type, the air flow, and AC or DC

power operation.

• AC fans are used when DC voltage is not available.

• All types of computer equipment rely on DC cooling fans.

SERVERS COOLING

SERVERS COOLING

The main two properties of cooling

devices are:

•1- Redundancy.

•2- Hot\Cold Swap.

Same as hard disks and power supply.

IBM X SERIES 255

IBM X SERIES 255

IBM BLADE CENTER H:

COOLING SUBSYSTEM

BladeCenter H rear chassis

Hot-swap customer serviceable

fan packs Hot-swap customer serviceable

AC blower units

COOLING OF RACKS WITH CONDITIONED AIR

Supply Air Raised Floor

Front In – Rear Out

Supply Air Raised Floor

Front In – Top Out

Front or Footprint Inlet

COOLING OF RACKS WITH CONDITIONED AIR

AIRFLOW

Liquid cooling (water)

What is liquid cooling ?

• Liquid (Water)cooling is a method of heat removal

from electrical components . As opposed to air

cooling, water is used as the heat conductor.

History

• Cooling hot computer components with various fluids has been in use since at least as far back as the development of Cray-2 in 1982.

• Through the 1990s, water cooling for home PCs slowly gained.

• it started to become noticeably more prevalent after the introduction of AMD's hot-running Athlon processor in mid 2000

Cont.

• As of 2011, there are several manufacturers of water cooling components and kits, and some custom computer retailers include various setups of water cooling for their high performance systems.

• Apple's Power Mac G5 was the first mainstream desktop computer to have water cooling as standard.

• Dell followed suit by shipping their XPS computers with liquid cooling.

Component.

Cont.

cont.

cont.

cont.

Radiators have different FPI (fins per inch) and therefor optimized for different type

of fans, the ones with high FPI are optimal with powerful fans where ones with low

FPI are better for lower RPM fans.

cont.

cont.

Video

Criteria and water flow

Advantages of liquid cooling over air cooling

• water's higher specific heat capacity, density, and

thermal conductivity. This allows water to transmit

heat over greater distances with much less

volumetric flow and reduced temperature difference.

• Drawing heat away from the processor and outside

of the system. This allows for higher clock speeds in

the processor as the ambient temperatures of the

CPU core are still within the manufacturer's

specifications.

Advantages cont.

• The water jacket around an engine is also very

effective at deadening mechanical noises, which

makes the engine quieter, Many high performance

CPUs require fan speeds in excess of 7000 rpm that

generate noise of 60+ decibels of noise.

• No DUST and no need to open computer to clean it.

Disadvantages.

• Costs significantly more than an air-cooled engine

system, approx. 600$.

• Size and weight ,need large area inside and out

side the computer require larger desktop system

cases to fit all of these parts within the computer

case itself ,approx.6.5Kg.

• and technical skills required to install a kit , suitable

tubes length , leaks could cause severe damage to

the components inside of the system.

cont.

• Leaking .

• Condensation, due to the ambient air right around

the pelt being cold.

• Water freezes at 0℃.

Usage

• Water cooling can be used to cool many computer

components.

• especially the CPU.

• GPU.

• Northbridge's.

• Southbridge's.

• Hard disk drives.

• Memory.

• Voltage regulator modules (VRMs).

• Power supplies can be water-cooled.

Coolant.

• This coolant contains a high quality anti-corrosion agent

for various materials including copper, aluminum, and

plastic, that prevents corrosion for long term operation.

• Material : Propylene Glycol & Anti-Corrosion Agent.

• Freezing Point : -9℃.

• Exchange Cycle : 1 year.

Liquid vs. Air cooling

Liquid Air

Cost high low

size big small

compatibility Specific CPU All CPU

safety less more

Skill required yes no

efficiency high moderate

spread low high

THANK YOU FOR YOUR ATTENTION