AHU/FCU Selection Calculator
Calculate Air Handling Unit and Fan Coil Unit sizing requirements
Space Requirements
Design Conditions
°C
%
°C
%
AHU Configuration
Calculation Results
Required Airflow
-
m³/h (- CFM)
Coil Capacity
-
kW (Total)
CHW Flow Rate
-
L/min
Fan Power
-
kW
Airflow Analysis
Fresh Air:
-
Return Air:
-
Supply Air Velocity:
-
Air Changes (ACH):
-
Coil Specifications
Sensible Heat:
-
Latent Heat:
-
SHR:
-
Coil Face Velocity:
-
Equipment Selection
Design Reference
Typical Air Change Rates (ACH)
| Space Type | ACH |
|---|---|
| Office | 6-10 |
| Conference Room | 10-15 |
| Classroom | 6-10 |
| Restaurant | 10-15 |
| Hospital Ward | 6-12 |
| Clean Room (ISO 7) | 30-60 |
Typical Pressure Drops
| Component | Pressure Drop (Pa) |
|---|---|
| Pre-filter (G4) | 50-80 |
| Medium Filter (F7) | 100-150 |
| HEPA (H13) | 250-350 |
| Cooling Coil (6-row) | 150-250 |
| Heat Recovery | 150-300 |
| Ductwork (typical) | 200-500 |
FCU Selection Tips
- • Select FCU at medium speed for design capacity
- • High speed provides ~15% more capacity
- • Consider noise level (NC rating) for space type
- • 4-way cassette: 600×600mm or 900×900mm ceiling grid
- • Concealed units need return air path
AHU Selection Tips
- • Face velocity: 2.0-2.5 m/s (typical)
- • EC fans offer 30-50% energy savings
- • Consider maintenance access space
- • Add 10-15% safety factor to airflow
- • VFD required for VAV systems