Knowledge
Understanding heat recovery systems
Heat recovery systems use the waste heat generated in processes instead of releasing it unused into the environment. This cuts energy costs and environmental impact. Here we explain how these systems work, the benefits they offer and what matters for efficiency and maintenance.
Reviewed by Dipl.-Ing. Wolfgang Buschmeier and M.Sc. Marius Buschmeier
Energy efficiency
Heat exchanger efficiency depends on the design, the temperature difference between the media and the materials used; as a rule it lies between 50 and 90 percent. To increase the efficiency of a system, four levers matter:
- regular maintenance and cleaning to preserve performance and avoid leaks,
- insulation against heat losses,
- optimised control systems for demand-based operation,
- integration into an energy management system that optimises consumption and generation.
How to calculate the efficiency of a heat exchanger in concrete terms is explained on our heat exchanger efficiency page.
Conclusion
Energy savings from day one, climate protection through reduced CO2 emissions, profitability through payback often within a few years: heat recovery is one of the most effective energy measures in existing plants. Request a tailor-made quotation from our experts today.
- Energy savings: Waste heat from industrial processes or heating systems is converted into usable energy - energy consumption and costs drop significantly.
- Environmental protection: Efficient use of waste heat reduces emissions of greenhouse gases and other pollutants.
- Cost efficiency: The energy saved offsets the investment over time; the need for separate heating or cooling systems may also decrease.
- Resource conservation: Lower primary energy demand conserves limited energy sources.
- Improved energy efficiency: Buildings and processes become more efficient - with potential advantages in public funding programmes.
- Less dependence on fossil fuels: A step towards a more sustainable energy supply.
- Flexibility: Systems are developed in various sizes and types to match the building or process.
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Capturing waste heat
Heat exchangers absorb heat from exhaust air, flue gases or cooling systems that would otherwise be released unused.
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Heat transfer
The captured heat is transferred to another medium in the heat exchanger - for example water or air - without the media coming into direct contact.
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Using the recovered energy
In industrial plants the recovered heat warms other processes or generates steam; in buildings it serves space heating, hot water preparation or supply air heating.
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Returning the cooled medium
The cooled medium returns to the process or the environment - the cycle repeats continuously.
Maintenance and servicing
- Inspection of piping, heat exchangers, fans, filters and controls
- Cleaning of components - fouled heat exchangers and clogged filters directly cost performance
- Checking and adjusting the control systems for optimum efficiency
- Leak testing of all connections and seals
- Checking driven machinery such as fans for function and wear
- Repair work: repairing or replacing worn components
Frequently asked questions
What efficiency do heat exchangers in heat recovery systems achieve?
Efficiency depends on design, temperature difference and materials. As a rule, heat exchanger efficiency lies between 50 and 90 percent.
Where are heat recovery systems used?
Primarily in industrial plants and in building ventilation systems - wherever waste heat occurs in exhaust air, flue gases or cooling systems.
How quickly does a heat recovery system pay for itself?
That depends on energy prices and utilisation. Every AWS-Technik quotation includes a profitability and payback forecast - systems often pay for themselves within a few years.
Send us your operating parameters
Media, capacity, temperatures — we size the right heat exchanger and get back to you with a quote.