Hi Willie,

At 12:57 PM 1/17/01 -0500, you wrote:
>Just a thought:  Maybe you could datapaq/mole the outside of the machine
>over a few hours and then figure it out based on surface area.

I think it would be difficult to get a good estimate this way as modelling
natural convection off a complex shaped object, which also has big
variations in temperature over its surface area, is going to get messy + a
lot of machines seem to also leak a fair bit of hot air from grills etc. If
the oven throughput was high it would also be neccessary to estimate how
much heat the hot boards coming out of the oven were dumping into the
factory environment, although this isn't too hard (e.g. a 1kg board with an
average heat capacity of around 1000J/kg.K coming out of the oven at 100C
above ambient temperature would deliver 100,000J of heat back into the
factory air. One board every 10s would then be 10kW).

David

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