A project requires both medium temperature (140° F at design) and low temperature (105° F at design) radiant floor panels. The system will also supply domestic hot water using an indirect water heater. The installer proposes the system shown in Figure 1. Assume each zone circuit requires a flow rate of 4 gpm when operating. Since the mod/con boiler has 1-inch pipe connections, the installer decides to use a 1 inch domestic hot water tempering valve to lower the water supply temperature to the lower temperature zones. He also decides to pipe the entire system with 1-inch tubing.
Can you spot at least six design or installation details that are going to create problems?