Commercial Generator Size Calculator
Calculate the right generator size for your commercial facility by entering your equipment details below.
Facility Information
HVAC Equipment
Motors and Machinery
General Loads
List of the Top 10 Best Generators:
Commercial Generator Sizing Guide
Common Commercial Generator Sizes
| Application | Typical Size Range | Common Uses |
|---|---|---|
| Small Commercial | 20-50 kW | Small offices, retail stores |
| Medium Commercial | 50-150 kW | Restaurants, medical offices |
| Large Commercial | 150-500 kW | Large retail, warehouses |
| Industrial | 500-2000 kW | Manufacturing, data centers |
Common Equipment Power Requirements
| Equipment | Running kW | Starting kVA |
|---|---|---|
| Air Handler (20 HP) | 15 | 45 |
| Chiller (100 Ton) | 110 | 330 |
| Motor (25 HP) | 18.7 | 56 |
| Air Compressor | 15 | 45 |
| Elevator | 20 | 60 |
Important Sizing Considerations
1. Load Analysis
Consider all types of loads:
- Critical loads requiring immediate backup
- Motor starting requirements
- Power factor correction
- Future expansion needs
2. Voltage Requirements
Common voltage configurations:
- 208V three phase for light commercial
- 480V three phase for industrial
- Power quality requirements
- Voltage drop considerations
3. Installation Requirements
Key installation factors:
- Local codes and permits
- Noise restrictions
- Fuel availability
- Environmental conditions
Frequently Asked Questions
What's the difference between kW and kVA?
kW represents real power (actual work performed), while kVA represents apparent power (total power supplied). The relationship depends on power factor: kW = kVA × Power Factor.
Why is power factor important?
Power factor affects the actual power available from a generator. A low power factor means you need a larger generator to supply the same usable power. Commercial facilities typically aim for a power factor of 0.8 or higher.
Should I consider redundancy?
For critical operations, redundancy configurations like N+1 or 2N should be considered. This ensures continuous operation even during maintenance or failures.