8/7/2019 Basics of Heat Transfer - Water cooling systems, pc
liquid cooling kit, cpu, video card, hard drive
1/2
SolidsDiamond 1000 - 2500
Silver 429
Copper 401
Gold 318
Aluminum 237Brass (37/15 Cu/Zn)159
Iron, pure 80.4Carbon Steel 54Bronze 50
Lead 35.3
Titanium, pure 21.9Stainless Steel 16.3
Ice (H2O @ -5C) 1.6
Glass 1.2 - 1.4Concrete 1.1
Rubber 0.16
Wood 0.12 - 0.04
LiquidsMercury 8.3
Water 0.67
3M Flourinert Fc-430.66
Methanol 0.25
Glycol, Antifreeze 0.25Ethanol 0.14
Liquid Nitrogen 0.14
GasesHydrogen 0.18
Helium 0.15
Air 0.026
Nitrogen 0.025
Oxygen 0.023
SolidsHuman Body 3.47
Concrete 3.3
Ice (H2O @ -5C) 2.1
Wood 1.7 - 2.7
Rubber 1.6
LiquidsWater 4.184
Methanol 2.55
Ethanol 2.48
Glycol, Antifreeze 2.38
Liquid Nitrogen 2.04Benzene 1.72
GasesHydrogen 14.32
Helium 5.23
Steam (at 110C) 1.97
Nitrogen 1.04
Air (at 100C) 1.0Oxygen 0.91
Moving Heat
As the First Law of Thermodynamics implies, matter and energy
can not be created or
destroyed (only converted between the two). Likewise, heat-the
movement of energy
from a hotter object to a cooler object-is never eliminated, but
only moved elsewhere.
This is the role of all cooling systems.
To acc omplish this, there are three primary modes of heat
transfer. Some forms oftransfer can be duplicated using multiple
methods (both natural and forced), but every
cooling system uses these same basic processes:
Conduction - the transfer of heat through matter with no net
displacement of the matter
Convection - the circulatory motion of a gas or liquid causedby
the variation of its density and the action of gravity
Radiation - the process of transferring heat by emitting
electromagnetic energy in the form of waves or particles
Thermal Conductivity
Thermal Conductivity is the amount of heat a particular
substance can carry through itin unit time. Usually expressed in
W/(mK), the units represent how many Watt s of heat
can be conducted through a one meter thickness of said material
with a one Kelvin
temperature difference between the two ends.
(Note: "Thermal Conductivity" is the measure of heat flowing
through a length, not to be
confused with "Thermal Conductance", which is the measure of
heat though a surface.)
Specific Heat Capacity
Specific Heat Capacity is the amount of heat a particular
substance can hold. Typically
expressed in KJ/(kgK), the rate depicts how many kilojoules of
energy are required to
change the temperature of one kilogram of said substance by one
Kelvin.
New Products!
*Specials*
Accessories
Cooling Blocks
Cooling Systems
Fans, Grills
Fittings, Nozzles
Heat Exchangers
Instruments
Liquid Coolant
LN2, DICE
Power Supplies
Pumps
Replacement Parts
Reservoirs
Software, Controllers
Tubing
Tubing Wrap
Valves, Fill Ports
GPU Hole Spacing
Quick Disc onnect Help
VGA Card Photos
Water cooling computers and electronics for11 years. Over460
active products!
Search (?)
2/23/2011 Basics of Heat Transfer - Water cooling
koolance.com/technical//002.html 1/2
8/7/2019 Basics of Heat Transfer - Water cooling systems, pc
liquid cooling kit, cpu, video card, hard drive
2/2
Aluminum 0.89
Glass 0.84Carbon 0.71
Diamond 0.50
Iron / Steel 0.45
Copper 0.39
Silver 0.23
Lead 0.13Gold 0.13
3M Flourinert FC-431.47
Freon 11 0.87Mercury 0.14
Previous: Introduc tion Next: Thermal Int erface Compound
What do all of these numbers mean in a liquid cooling
system?
The above thermal conductivity shows why copper is the preferred
cold plate material
for cooling systems. It is extremely close to silver in
performance at a fraction of thecost. Like most metals however,
copper doesn't hold heat for very long-- it needs to be
absorbed by something else.
The specific heat capacities show water to be the best liquid
for holding heat.
Practically, it is also the best for transferring it.
This would indicate the ideal configuration is to use copper to
transfer heat from the
processor, and to use water to absorb and move away the heat.
Although there aremany other factors involved, here you have the
basic foundation of a liquid cooling
system.
Lega l Po li ci es Contact
2/23/2011 Basics of Heat Transfer - Water cooling
koolance.com/technical//002.html 2/2
