Author Topic: Calculating tenability of radiation  (Read 2387 times)

Offline GB

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Calculating tenability of radiation
« on: November 11, 2018, 06:34:49 PM »
I have a scenario where I am trying to measure the radiative heat transfer and subsequent tenability within an open plan apartment and the relationship between cooking facilities and the means of escape.

I am considering using the calculation where:

q=Stefan-boltzman constant x T(absolute temp in Kelvin) x A (area of emitting body)

Would the forum agree this is the correct formula or is there another formula to prove that the radiative heat does not exceed 2.5Kw/m2?

If anyone has used this formula, is the temperature measured at the source of at the various points along the MoE?

Offline lyledunn

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Re: Calculating tenability of radiation
« Reply #1 on: November 12, 2018, 08:11:46 AM »
I am not familiar with the formula. However, in dynamic context any constant involved surely means that the validity of the outcome is time limited?

Offline Tom Sutton

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Re: Calculating tenability of radiation
« Reply #2 on: November 12, 2018, 04:20:18 PM »
My mathematics is limited to long division but a very long time ago we use to use a nomogram to measure the safe width of corridors, the information in the paper may be relevant to your OP.

Check out www.iafss.org/publications/frn/765/-1/view/frn_765.pdf you never know.
« Last Edit: November 12, 2018, 04:21:59 PM by Tom Sutton »
All my responses only apply to England and Wales and they are an overview of the subject, hopefully it will point you in the right direction and always treat with caution.

Offline Fishy

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Re: Calculating tenability of radiation
« Reply #3 on: November 13, 2018, 08:58:10 AM »
It's been a while since I've done these, but it doesn't look right to me.  There's no emissivity in the equation, nor is there a configuration factor.  What you've got looks similar in form to the calculation for an emitted heat flux (I1 = εσT4), if you had assumed an emissivity of one, but that doesn't tell you what's falling on the 'receiver' (i.e. the occupants).

If I recall correctly, the SFPE Handbook is the 'go to' reference for this type of calculation.