A heat-recovery proposal becomes more useful when it names the heat consumer. Without a demand that coincides with compressor operation, an impressive available-heat figure can describe energy that the plant still has to reject.
Atlas Copco’s energy-recovery guidance identifies compressor cooling design, distance to the consumer, required temperature and continuity of heat demand as important project variables. Those inputs should come before a savings calculation.
Choose the useful route
Kaeser describes two broad approaches: using warm cooling air for space heating, or transferring heat into water for services or production. They create different integration questions.
For air recovery, identify the heating season and the destination for the warm air. For water recovery, establish the temperature the user needs and the heat-exchanger arrangement suited to the compressor and water conditions. The temperature available from one equipment configuration should not be promised for every machine.
The compressor must also retain its cooling function when recovered heat is not wanted. Ask the equipment supplier how the proposed arrangement rejects surplus heat and maintains the required operating conditions.
Make coincidence visible in the calculation
Consider a simplified screening example, not a measured installation:
- An assessment establishes 50 kW of usable thermal output at the consumer’s required conditions.
- That output and the heating demand overlap for 2,000 hours per year.
- Useful recovered heat would be 100,000 kWh per year, before any additional losses not already included in the assessment.
The result follows from 50 multiplied by 2,000. It is thermal energy, not an equal amount of avoided compressor electricity. If overlap is only half as long, the useful heat halves too. A different heating system’s efficiency and operating cost are separate inputs to an economic comparison.
Ask for an integration schedule
Map compressor operation against the heat user’s working hours and seasonal demand. Identify the temperature at each side of the exchanger and the distance between source and consumer. Specify which pumps, controls and maintenance tasks the project adds.
For verification, agree how delivered heat will be established and which existing heating duty it replaces. Report unused available heat separately. This keeps a technically feasible recovery project tied to a real plant requirement and makes the eventual result easier to assess.
