Fan coils provide conditioned air to an area by recirculating air through the coils. A four-pipe fan coil unit consists of a fan, air filter, chilled water cooling coil, and hot water heating coil.
Required Objects
The four pipe fan coil must have the following properties.
- It must be connected to a hot water loop.
- It must be connected to a chilled water loop.
- It must be attached to a conditioned zone.
Design Assumptions
If the Draw Ventilation property is selected, the following will occur.
- The unit will provide the design outdoor air flow.
- The fan will run constantly during occupied hours.
If the Draw Ventilation property is not selected, the following will occur.
- The unit will not provide any ventilation.
- The fan will cycle on and off to meet conditioning needs.
| Property | Value | Notes |
|---|---|---|
| System air flow | Constant | |
| Cooling supply air temperature | 12.78°C | |
| Heating supply air temperature | 40°C |
Cooling Coil
The cooling coil has the following assumptions.
| Property | Value | Notes |
|---|---|---|
| Design coil leaving air temperature | 12.78°C | |
| Chilled water design inlet temperature | N/A | Set by the chilled water loop. |
| Chilled water design outlet temperature | N/A | Set by the chilled water loop. |
Heating Coil
The heating coil has the following assumptions.
| Property | Value | Notes |
|---|---|---|
| Coil leaving air temperature | 40°C | |
| Hot water design inlet temperature | N/A | Set by the hot water loop. |
| Hot water design outlet temperature | N/A | Set by the hot water loop. |
Supply Fan
The supply fan has the following assumptions.
| Property | Value | Notes |
|---|---|---|
| Pressure rise | 250 Pa | |
| Total efficiency | 70% | |
| Motor efficiency | 94% |