LED Light is efficient. Far more efficient than the HID, fluorescent or
incandescent bulbs they replace. But not all energy LED consumes is
converted to light. Some of the energy is used to create heat. And while
LED is far more efficient than the other light sources at producing
light and very little heat, the heat it produces must be removed.
Why do you need cooling?
the heat from the LEDs extends the life of the product. Think of an LED
light installed inside a cooler or freezer area. The ambient air is
cold. The entire air source of the cooler area acts as a heat sink,
keeping the LEDs performing extremely well and efficient for years. And
while it is impractical to only install LEDs inside a cool environment,
having a heat sink to remove this heat is the next best thing.
Removing Heat: Active Cooling
what is active cooling? Typically, this means fan. This type of cooling
has been used for decades on other types of electronics: computers,
laptops, TV’s and amplifiers. Fan’s blow a steady stream of air onto a a
heat sink and transfers the air away. If inside an enclosed fixture,
this hot air is then moved to the fixture itself, thus acting as a
secondary larger heat sink. It creates airflow inside the enclosed
fixture, creating turbulence over the face of the LED’s, removing any
static heat that might built up that might build up without the present
Within the LED industry, there had been a debate on
whether fans are good or not. Some who think they are bad claim they are
a point of failure. And over the years, we have heard these types of
arguments as well. However, the truth of the matter are fans are
extremely robust and rarely fails. MyLEDLightingGuide has sold 1000’s of
active fan retrofit kits over the past 10 years, and have maybe seen 2
failures. In both cases, water intrusion into the fixture caused the
fans to fail.
The benefit to an active fan solution is the
physical size of the heat sink required is significantly smaller. So
retrofitting an existing fixture, replacing the bulb and ballast with a LED Retrofit Kit, makes sense. Without the active fan, the heat sink would be too large to fit into the existing fixture.
Removing Heat: Passive Cooling
why not use a fan all the time? Well, you don’t need to. Lighting
designers can integrate the heat-sink as the fixture housing, combining
both form with function. Take our LED UFO High Bays.
The UFO part of the fixture is the heat sink. It is significantly large
enough to absorb the heat produced by the LEDs, and radiate the heat
away from the fixture. These types of fixtures are typically not
installed inside other fixtures, so it can utilize what ever available
air flow is available to help remove air that is available. Outdoors,
there are available breezes that can effectively remove heat. So
creating a stylish fixture that radiates heat away is practical and
economical. Engineers can easily design the right size heat sink to
accommodate the removal of heat for the fixture they are designing.
So What Better?
They are both good. Both are perfect for the solution they were
designed to solve. Fans are extremely robust. So you should not let the
fan, if a retrofit is your best option, be the deciding factor on moving
forward with either an active cooling or passive cooling solution.
Reposted from MyLEDLightingGuide Blog