Consider a steady-flow heat exchanger involving two different fluid streams. Under the conditions of no heat and work interactions between the heat exchanger and the surrounding medium, the amount of heat lost by one fluid will be equal to the amount of heat gained by the other.

Selma made a diagram to compare convection and radiation. which label belongs in the area marked x? must involve temperature differences between substances or objects only occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter