When building your loop there should be a list of things that come to mind, flow and pressure should be near the top of that list. Pressure drop is the measurement of inlet pressure minus outlet pressure, or the pressure lost of flow through the radiator.
I have the line from my wash basin in the mud room hooked up to the gate valve controlling flow, which then runs into the King flow meter. The bottom port on the flow meter is the inlet, top port is the outlet. The outlet runs down to the Delrin T which I have Bitspower 1/2″ barbs on for the normal flow, and the negative pressure line connects via an EnzoTech 1/4″ fitting. After the negative pressure T, the component in testing is attached. I always use Bitspower 1/2″ fittings, that keeps everything on a common test platform…well from a fitting perspective anyhow. At the outlet of the component is the positive pressure T fitting, again with Bitspower 1/2″ fittings and an EnzoTech 1/4″ fitting for the pressure line. The tubing the runs back into the wash basin and down the drain.
Some of you are looking at the pressure drop curves and scratching your heads thinking: wait a minute, you added another radiator…how can the pressure drop be lower? Back to the start here; Pressure drop is a method of measuring energy loss (flow in this case) or restriction through the component. With a parallel setup like the MCR Stack, you are giving the water more paths to flow and lessening the restriction or loss through the radiator. The MCR series was not a restrictive radiator to begin with, but the parallel setup brings even less restriction to your loop, you should have no concerns about adding a MCR320-Stack to your existing MCR320 and the resulting restriction or flow rates.
Now to the thermal tests, but before we do, lets make a stop and cover the Test Specification and Methodology prior to diving in.