Fan Coil Cooling Sizing

When using the Fan coil cooling sizing method, the Cooling design calculation is made through a detailed EnergyPlus simulation using Compact HVAC Fan coil equipment. A diagram of the system layout used is shown in the Fan Coil Units topic.

Each zone has it's own Fan coil unit with a fan (generating no pickup), a water-cooled cooling coil, an outside air controller and a zone terminal box with a damper to reduce supply air flow. More specifically:

No economiser,
No heat recovery,
No heating coil,
Zero pressure rise fan,
No humidification/dehumidification,
Outside airflow rate and operation schedule defined by the data under the Mechanical Ventilation header on the HVAC tab at the zone level (see note below about outside air flow rates),
Cooling coil availability defined by the schedule under the Cooling header on the HVAC tab at the zone level,
Zone design cooling temperature setpoints are defined by the data under Environmental Control on the Activity tab.

Unlike the ASHRAE cooling sizing option, Fan coil can be used in conjunction with Natural ventilation.

Design supply temperature

The constant dry-bulb air temperature of the air supplied for cooling the zone

Note: the Fan coil outside air flow can be fully on or fully off but cannot reduce to fractional values in between. You may therefore get higher outside air delivery rates than with the other methods if you are using Schedules and your Mechanical ventilation operation schedule has fractional values.