Hi, I would really like some insight here, I don't know what I'm doing! also, sorry if i get the terms wrong and miss the obvious, this isn't my field. I will try to keep this short: I think that if you have a solid object, with a Heating element in the centre, and the surface in ambient temperature, then any point inside that object will have a steady state temperature determined only by the difference between the element and the ambient, with some coefficient related to position. (like the midpoint of a rod will always be half way between its to ends). can this idea be carried over to a sealed container with a fan/heater inside, and the ambient heat-sink on the outside? meaning, say ambient was 20°, and my fan heater was putting out 40°. if I pick a random point and measure its SS temp as 25°, will that point always have a SS temperature given by the formula ambient + (heater - ambient)/4 ---------------------------------------- I'm thinking mainly of forced convection, where the airflow stays the same but the heater and ambient temperatures vary. I don't think pressure would have much to do with it, because the container is very sealed. I suppose the question is will the airflow from the heater have a different pattern depending on its temperature? if it is the same pattern for all temperatures, then the heatflow will be along the same paths, and behave like a solid object. is this model likely to work out? what assumptions have i made? is there a better (and still simple) model? thanks very much! edit: is there a better place for this question? Mechanical Engineering perhaps, or even Classical Physics?