Applying Thermostatic Mixing Valves for Trouble free Operation

[@lesliepercival6915]

After finding the system curve for my hydronic system, I found a pump whose pump curve crossed at exactly the operating point I needed. However, then I read idronics 7 and discovered that I need two thermostatic mixing valves as per Figure 6.3. But these double my total head loss! Will the second pump on the bypass loop compensate for this once the system is up and running through the two mixing valves?

[@CaleffiHydronicSolutions]

Thanks for the question! Yes you need to calculate the flow resistance of every fitting pipe, device in the circuit, then confirm that the circulator can provide the adequate GPM at that pressure drop. In Idronics 16 we take you through an example of how to calculate the pressure drop in a circuit. The drawings and pictures help explain the procedure. www.caleffi.com/usa/en-us/technical-magazine We hope this helps.