The Ins and Outs of Temperature Control Units

If the fluid is returning to the TCU lower than the setpoint, this means energy is being transferred from the fluid into the process. [...]the TCU is heating the system. Indirect designs still use a cooling valve, but the process loop's fluid is isolated from the cooling source fluid with a heat exchanger. For this reason, simply assuming that all 1-hp pumps are the same can create scenarios where either the required flow rate is not achieved, or energy (and operating costs) are wasted because a 2-hp pump was installed when another manufacturer's 1-hp design could provide the same performance. Laminar or turbulent flows are governed by a ratio known as the Reynolds number, which considers the density of the fluid, flow speed and viscosity over a defined length.