Power and installation:
- For every horsepower, a compressor delivers 4-5 cfm (m3/hr), at 100 psi (7 bar) pressure .
- A 50 HP air compressor can produce up to 12 gallons / 45 liters of water per day (with only 8 running hours daily).
- Air receivers should be sized about 4 gallon capacity for each CFM of compressor capacity. That's 9 liters per m3/h in metric units.
For example, a small 20 cfm compressor needs an 80 gallon air receiver.
Costs and energy savings:
- On average, compressed air costs about 30 cents per 1000 cfm (1700 m3/hr). This depends on the size of the compressor and includes electricity, purchase price of compressor and maintenance costs.
- A 50 HP air compressor will cost you about 25.000 dollars in electricity cost per year (at 6.000 running hours per year).
- Every 2 psi (0.15 bar) of pressure drop in your system will cost you 1% extra in energy cost (this adds up quickly!!!)
|Pressure - Rule of Thumb|
- Lowering Compressor Inlet Air Temperature 10° F (5.5 °C) will result in a 2% energy savings.
- A two stage reciprocating air compressor is about 15% more efficient compared to a single stage unit.