Williams Comfort Products Fan Coil Piping Instructions

Ensuring the correct inlet and outlet locations is vital for both chilled and hot water coils. Otherwise, HVAC equipment may fail to properly warm or cool the space. If you’ve been called for an installation, you may need some Williams Comfort Products fan coil piping instructions to help get you started. 

The following steps are applicable to the Williams Comfort Products Horizontal model.

Fan Coil Piping Tips

Before you begin piping, you need to determine whether you’re installing a two-pipe or four-pipe fan coil.

Two-Pipe Coil

A two-pipe coil only has one inlet and one outlet. Consider the following tips for proper piping:

• Pipe sensor location – Be sure to clamp the pipe sensor onto the water supply line as close to the incoming water source as possible. This helps it sense water temperature at its set point.
• Inlet & outlet location – The inlet is always at the bottom of the coil and the outlet is at the top. Coils should always be piped so that the inlet is always on the row farthest downstream from the incoming air. 
• Circuit variations – The coils may have more than one circuit. Due to various circuit options, the inlet and outlet may change position. 

Four-Pipe Coil

These coils have dedicated chilled water coils and hot water coils, each with their own inlet and outlet. Consider these tips for piping:

• Number of pipes – Because there’s two dedicated coils, there will be four pipes total. Each coil has its own inlet and outlet. 
• Common tube sheet – All coils will have a common tube sheet for four pipe coils.
• Control wiring – The controls are wired so either the chilled water coil is running or the hot-water coil is running. They will never run at the same time. 
• Pipe sensor – Since each coil is controlled individually, a pipe sensor isn’t necessary. 

Hose Kits

If you’re using a hose kit, keep the following in mind:

• Hosing location – Be careful not to install hoses over any electrical components such as j-boxes and actuators.
• Hosing insulation – It’s recommended that flex hoses be field insulated during installation. 
• Inspect hoses – Before you install the flex hose, check it to ensure the metallic sealing surface is flat and smooth with no sharp edges or scratches.
• Inspect the gasket – Check the sealing gasket is properly installed onto the end of the hose.
• Union connection – Be careful not to over tighten the threaded union connection or it can damage the gasket or sealing surface. It’s recommended to hand tighten the union and then use a wrench no more than a ¼ turn.
  • Note: Don’t apply pipe dope or thread sealant to the sealing surface or pipe threads.