What factors affect the pressure or flow loss?
The internal flow area is the major controlling factor. The next most significant factor is the internal design of the tube. A high-density lanced offset (turbulence producing fin) can produce twice the pressure loss as laminar fins in the same size tube. Tube length is the next biggest consideration. A tube twice as long as another will have nearly twice the drag at the same air velocity. For the lowest possible pressure loss in a given space, orient the tanks so that you have many short tubes. Clearly, this optimizes the internal flow area. However, it can also drastically affect thermal performance. The packaging issues cannot be ignored. For example, tank height has to be about 2 ½” in most cases. Say our total available face area is 20″ x 10″ (not an unusual proportion). If we chose to apply our “many short tube” rule, this would mean that our tube length would be 5″ (10-(2*2.5)=5). The tanks consume half of our available face area. Our core face area is 100 in^2 (5 * 20 = 100). O
