Screw Compressor Heat Recovery Calculator

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📌 Disclaimer

This tool provides estimates only based on the assumptions stated above (IEA 2024 factors, full heat utilization, screw compressor profiles). Actual energy recovery, cost savings, and emission reductions depend on site‑specific conditions, actual operating hours, heat demand, equipment efficiency, and local energy prices. Results are for preliminary assessment and informational purposes only – they do not constitute a guarantee, professional engineering advice, or a financial promise. Always verify with a qualified engineer and use real‑world data before making investment decisions.

User Guide

Step 1: Gather Your Compressor Data

Before opening the tool, you need to find specific data about your compressed air system, usually found in the compressor’s technical datasheet or SCADA system.

Step 2: Fill in the Inputs (Left Side)

Thermodynamic Inputs

  • Recovery Potential Loaded (Q1) [kW]: Enter the heat recovery potential when the compressor is running at full load. (Default: 160 kW).
    • Tip: This is usually 70% to 94% of the motor shaft power. If your compressor motor is 200 kW, you might enter 180 here.
  • Recovery Potential Off-loaded (Q2) [kW]: Enter the heat recovered when the compressor is idling/venting. (Default: 20 kW).
  • Demand Period (TR) [hrs/yr]: How many hours per year does the compressor run? (Default: 4000).
    • Example: 24/7 operation = 8760 hrs. Single shift = 2000 hrs.
  • Duty Cycle (K1 / K2) [%]:
    • K1 (Loaded): Percentage of time the compressor runs under load. (Default: 85%).
    • K2 (Off-loaded): Percentage of time it runs idle. (Default: 15%).
    • Note: These two numbers must add up to 100%.

Step 3: Fill in the Inputs (Right Side)

Environmental & Financial

  • Displaced Fuel Type: Select what energy source the recovered heat is replacing.
    • Natural Gas: If you are replacing a boiler.
    • Grid Electricity: If the heat replaces electric heaters.
  • Currency & Rate:
    • Select your currency (USD, EUR, etc.).
    • Rate: Enter the price you pay for energy.
      • If you selected Natural Gas, enter the price per kWh (e.g., 0.15).
      • If you selected Grid Electricity, enter your electricity rate per kWh.
  • Source Efficiency (η) [%]: Enter the efficiency of the system being replaced.
    • If replacing a gas boiler: Enter 85-90%.
    • If replacing electric heating: Enter 100%.

Step 4: Run the Analysis

  • Click the blue EXECUTE ANALYSIS button.

Step 5: Read the Results

The bottom panel will display three key figures:

  1. Recovered Energy (kWh/yr): The total thermal energy available from your compressor annually. This is a measure of the resource you have.
  2. Financial Offset ($/€/¥): The amount of money you will save per year because you are not paying for the fuel you selected in Step 3.
  3. CO2 Avoided (Tonnes/yr): The total carbon dioxide emissions prevented per year.

Example Scenario

Let’s say you have a 250 kW compressor running 24/7.

  1. Q1: Enter 220 (Heat recovery potential).
  2. Q2: Enter 30 (Heat when idle).
  3. TR: Enter 8000 (Hours per year).
  4. K1: 85 / K2: 15.
  5. Fuel: Select “Natural Gas”.
  6. Rate: Enter 0.15.
  7. Efficiency: Enter 90.
  8. Click EXECUTE.
  9. Result: The tool will show you how much money and CO₂ you save by using that recovered heat for your factory heating.