The Challenge
A facility's production equipment (furnaces, compressors, hot presses) continuously generated waste heat, requiring active cooling via fan systems. Annual cooling energy cost was ₹12 lakhs. Simultaneously, the facility heated water for cleaning and process use, consuming ₹8 lakhs annually.
What Became Visible
Thermal analysis revealed equipment generated 150 kW continuous waste heat at 65–75°C. This heat was being dissipated via cooling fan systems. Meanwhile, the facility was heating water from 25°C to 45°C for cleaning — consuming 25–35 kW of heating energy. A heat exchanger could transfer waste heat to the water heating system.
What Changed
Heat recovery system installed: waste heat from production equipment captured via heat exchanger, used to preheat water before electric heater. Cooling fan load reduced due to recovered heat.
How it worked: A 100 kW plate heat exchanger was installed in the waste heat stream. Facility's hot water system now uses waste heat as primary preheating source (raising inlet water from 25°C to 45°C using equipment waste heat), then electric heater supplies final heating to 55°C only when needed.
Results
of 150 kW available
less fan operation
waste heat covers most preheat
cooling + heating reduction
Waste heat is valuable energy that's usually discarded. Capturing and reusing it provides double benefit: reduces waste removal cost (cooling) and reduces other heating costs.
Operational Reality
Most manufacturing facilities with process heating generate 50–150 kW of waste heat. Heat recovery systems recover 30–60% of this, delivering 2–4 year payback.