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Mike M
01-19-2008, 07:01 AM
Does "heat sink" only mean absorb heat, or is the term also inclusive of getting rid of heat rather than just receiving it and storing it?

Other than aluminum being good for disipating heat quickly, I have no idea about heat sink properties of copper, or brass or bronze, other than brass and bronze retain a lot of heat. My assuption for a good heat sink: not only does the material need to pull off heat from the lamp, but also get rid of it. Also, is spun metal better for this than cast? Thin wall better than thick or vise-versa?

Do heat sinks extend lamp life and keep sealants healthy?

Tanks,

Mike

Pro-Scapes
01-19-2008, 07:45 AM
your right... allum is very good at disapaiting heat. A heat sink can have fins or or other shape that basically just increases surface area to help remove that heat.

Some applications like computer processor heatsinks use a fan directly mounted to the sink aiding in airflow over these fins. Any fixture in which you place a lamp in and then seal it will esentially become a small oven. and over time cook anything inside. I am unsure of the properties of brass and copper and bronze at disapaiting heat. I know allum is way up there. Pull an allum pan from the oven and moments later you can comfortably touch it.

irrig8r
01-19-2008, 10:47 AM
Good questions Mike. Been thinking about them myself regarding LEDs, and I know Billy is right about aluminum. The main issue being it doesn't hold up as well to the elements as brass or copper. Solve that issue and I think you have a viable long-lived, low maintenance fixture.

INTEGRA Bespoke Lighting
01-19-2008, 11:55 AM
A good heat sink can have several different qualities. Certainly aluminum is a good metal for transferring heat, but it is not dense like brass is. A good aluminum heat sink example would be the Nightscaping Guardian, Stylist, etc. These are extruded aluminum that use fins to increase surface area which makes up for the lower density.

Copper is also an excellent heat conductor of heat. All of the best chef's in the world use Copper pots and pans for this reason; The heat is absorbed and spread quickly and evenly through the material. Brass is pretty good as well, but generally for another reason....

Another way to create a good heat sink is with thermal mass or density. Cast Brass, Bronze, and solid billet Copper make excellent heat sinks because of their dense thermal mass. They absorb a lot of heat into that mass, where it travels evenly and completely thorugh the mass and is equally shed off the back side. Add to that mass some form of fins or otherwise increase the surface space and you have an amazing heat sink.

CAST Treelights & Bullet Uplights, HUNZA DL & WS, Nightscaping Guardian & Stylist, Lumiere 203BR, and others like them are excellent for shedding heat.

There was some talk not too long ago about CSA altering their standards and introducing a heat threshold into their lighting specifications in a effort to reduce the number of burns suffered by people contacting hot fixtures.... not sure what ever happened with that.

Regards.