Can anyone explain these to me? I understand how they would send warm water through the coil in the winter and cold water in the summer. Did a unit yesterday where both the heat and the cooling system seemed to work. How could both the chiller and the hot water be hooked up at the same time?
Also, starting to see Sharkbite flex tubes on water heaters. I see Sharkbite makes them specifically for water heaters so they are OK?
If you got both heating and cooling out of it, then this sounds like a single-fluid, two-pipe, water-source heat pump system. You’re in the right climate for it. They work well. Here’s a photo of one. This one operated with a cooling tower during the summer, and a gas fired hydronic boiler in the winter. Loops can work two ways: 1) either with a closed building loop and open cooling tower loop (interface is a plate and frame exchanger) and a hydronic boiler installed in the closed loop (and shut off in winter), or 2) with a single open loop and cooling tower, with a bypass to a hydronic boiler in the winter.
Or, what you saw was a two-pipe fan coil system with a single thermal fluid loop, with chilled water in the summer and hot water in winter. These loops work in three ways: 1) cooling-only, 2) heat-only in cold weather, 3) free-cooling mode in the fall and spring (if there’s a cooling tower present). But you couldn’t get both heating and cooling out of it unless it was a four-pipe system.
Four pipe systems are exactly that: supply and return chilled water, supply and return hot water.
Another possibility is a water-source DX unit with electric heat coils. Or a chilled water fan coil unit with electric heat coils. A photo of the dataplate would settle this.