heat calcs

[potter 2]

Any body any good at heat calculations.
I have a sealed space of 66cubic mts.about 8 x4 x2 and a bit  Ambient temp 12 c . how much heat/energy would it need to take that space up to 230 c. in 30 minutes           Ive tried one formula that gave me millions of joules that became some strange figure in watt/hrs But can i have an answer as MWatts  to compare with fire loadings of known size....If you are really good ..tell how did you do it.

[John Webb]

If a fire has a size of 1MWatt, then it's putting out 1M joules every second as one watt=1 joule/sec
So if you've calculated the total heat release rate of the fire in joules, then you also need to have the duration of the fire in seconds. So we have:
(Total heat release)/(duration of fire in seconds)= average size of fire in Watts

Hope this helps.