Join Date: Aug 2010
Location: Lake Orion, MI
Thanked 19 Times in 13 Posts
HID lights and heat build up - here is the mathematic analysis behind our issues...
First, we start with looking at where the energy goes?
Visible Light 8%
Infra Red 73% (needed to keep the filament warm)
Total Radiant Energy 81%
Heat (Conduct + Convect) 19%
Heat (cond+conv+IR) 92%
Visible Light 27% (This is the reason we switch...)
Infra Red 17%
UV 19% (Unwanted side effect - don't stare at HIDs too long, you'll get snowblind!!!)
Total Radiant Energy 63%
Heat (Conduct + Convect) 37%
Heat (cond+conv+IR) 54%
Since I switched a 55w incandescent to 100w HID in my High beams, this is my story:
A 55W incandescent will generate 10.5W of heat and 50,6W (92%) of heat + IR. The Infrared is needed to keep the filament warm to maintain glow so a necessary evil. A 100W HID will generate 37W of heat and 54W of heat and infrared.
Depending on the heat disappation (conduction and convection components in my lens), theoretically, I might see as much as 4 times the heat build up. If you figure the infrared component too, I will only see a 8% heat increase compared to 55W halogens. This will be interesting. Currently, my lights are holding the 100w/55W HIDs without any problem, which leads me to beleive that the Infrared component is contributing significantly more than 0 to the overall heat build-up in the Halogens; Hence, The required delta heat disappation will be in the lower ranges, and which is the reason that my setup works without melting anything.
So far so good.
Last edited by Anders; 04-26-2012 at 02:41 PM.