🔍 Key Concepts

• One-pipe vs. two-pipe hydronic systems – how the water actually flows through coils/radiators • Series connection of heating coils – what happens to water temperature as it moves from one coil to the next • Effect of heat transfer – how giving up heat to each coil changes the water temperature

💭 Think About

• Visualize the piping: does the same stream of water pass through coil 1, then coil 2, then coil 3, or does each coil get its own supply and return? • If hot water gives up heat to a coil (to warm the space), will the water leaving that coil be hotter, colder, or the same as when it entered? • If the water temperature is changing as it flows, would the next coil see the same inlet temperature or a different one?

✅ Before You Answer

• Be clear on whether a one-pipe system sends water through coils in series or in parallel. • Decide whether the water temperature should drop or rise as it moves from one coil to the next in a heating system. • Match the correct combination: same vs. different inlet temperature at each coil, and rising vs. dropping water temperature along the line.