Halogen Bulb

[heavenly]

Hi

How to calculate heat emitted on a alluminium parabolic reflector from a 250w halogen bulb.

Duration of ligh on ; 15Min

Thanking You
John

 

[m777182]

I would rather measure it then calculate it.
m777182

 

[scalleke]

A 250 W Halogen bulb will give of a certain no of lumens. 1715 lumen = 1 KW/m^2.

The Al relector will reflect part of the energy and absorb some to heat itself up. The reflection / absorbtion ratio will depend on many factors such as the surface treatment of the Al reflector.

HOw hot the reflector will get will then be determined by the thickness od the reflector and it's insulation as a lot of the heat will be immediately lost to the ambient air.

Too many variables. m777182 is right make a test set up and measure it. Change ambient temperatures. Air speed and reflector position to try to establish correlation.

best regards.

scalleke

 

[IRstuff]

A typical bulb is well less than 50% efficient, so the majority of the heat on the reflector comes from just the heating of the filament.

TTFN

 

[EdStainless]

Worst case, all 250W as radiation load.
Need to look at reflectance/absorption values for Al. You would need this information as a function of wavelength. And you will need the wavelength output for the lamp.
You will need to measure it, it gets too complicated.

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Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm