L1s - Fan Coil Units (FCUs)

What is an FCU?

A Fan Coil Unit (FCU) is a relatively small HVAC unit containing a fan and heating and/or cooling coil used to condition a local space.

What usually provides heating/cooling to an FCU?

Chilled water, hot water, electric heat, or sometimes refrigerant depending on the design.

What is a 2-pipe versus 4-pipe FCU?

2-pipe: one water circuit normally switches seasonally between heating and cooling.

4-pipe: separate hot-water and chilled-water circuits allow heating or cooling as required.

What should be commissioned?

Fan speeds, coil valves, thermostat, heating/cooling operation, condensate drain, filters, airflow, and BAS interface.

Common FCU problems?

Air in coils, plugged strainers, stuck valves, failed fans, blocked condensate drains, and poor thermostat/sensor location.