What's more efficient, a single-pass or multiple-pass heat exchanger?
There are several factors that go into the performance of a heat exchanger. First is surface area but equally important is the overall heat transfer coefficient and that can be affected by the velocity of the fluids flowing through the exchanger. Finally the approach temperature is also important. The closer the temperature of the two steams get the more heat is transferred. Having said all of that, the number of passes is only a factor in how these variables are achieved and of course it can also set the cost of the exchanger. Bottom line, you can not say a single pass or multiple pass is more efficient.
