Abstract: A heat exchanger housing containing a filmed heat exchanger coil, the heat exchanger used to either heat or cool gases, and materials suspended in the gases, as they pass through the housing. The heat exchanger housing includes a substantially rectangular body, such as a square body. On the exterior of the heat exchanger housing is placed an inlet and an outlet. In specific implementations, the inlet and the outlet are positioned on opposite sides of the rectangular body. The inlet and outlet are each substantially circular. Joined to the substantially circular inlet and outlet are conical transitions that join to circular carrier lines. The carrier lines direct gases toward or away from the heat exchanger housing. Conical transitions provide a way to direct the gases from the circular carrier lines into the exchanger housing with a minimum of difficulty, with increased efficiency, and with avoidance of problems from metal fatigue at the corners of traditional transitions.

Abstract: An air to air heat exchanger maximizes the space that is available for cooling process air while keeping the pressure drop of the process air through the heat exchanger at a minimum and at the same time utilizes easily available components for manufacture. A pair of headers are provided in the air to air heat exchanger and the headers are connected with a plurality of tubes arranged in a triple tube arrangement such that there are a plurality of sets of three tubes in each set. The sets of tubes are spaced along the length of the headers. Each of the tubes are bent into an "S" shape so each tube has three lengths or sections extending from side to side of the heat exchanger between the input header and output header.