Hi guys, I kept trying different searches in Google and it kept bringing me to threads on this forum, so I thought it was time to join. I'm trying to calcuate the heat transferred into the environment from an air system and am having a bit of trouble... I really don't have very much experience with this at all and I feel like its a pretty common issue, but I don't know where to start. The situation: I have a system of non-insulated pipes, it starts at one location with warm air flowing through it, at one point the pipe splits and runs to two different air to air coolers. I know the size of the pipes, the materials, the k values, the lenghts of pipe, and the temps at all three end points... but I feel like just using the standard form of Fourier's law that I've found doesn't really work, the temperature inside the pipe isn't constant (it cools from points A-B and A-C) and I feel like there would be a curve made by the heat transfer.. Starting off with a greater value at the beginning, and decreasing as a curve as the air in the tube cooled. Does anyone have any input on what I should be looking for as an equation? I'm seeing a situation where if you had a steam system, for example, and knew the lenght, pipe size, starting temp and environmental temp you could calculate the final temp... but like I said, I knew to this type of situation. Any help would be awesome. Thank you in advance!