Save Money with Heat Exchangers

A heat exchanger in an air handling unit is almost always a worthwhile investment - regardless of whether the exchanger in question is a rotary or a plate type.

All our units save so much energy that the investment can be repaid in no time.

Where significant air volumes are treated, the amortisation period may be less than a year in some cases.

There is generally a solution for any air volume that offers a maximum payback time of two and a half years.

Air-to-Air Heat Exchangers: Comparison of Payback Times

Viability: Example of Axalta Coating Systems

The savings and amortisation effect can be seen in the following viability calculation using the example of Wuppertal-based Axalta Coating Systems Germany GmbH. Despite an estimated investment outlay of some €625,000 in an overall ventilation system with twelve heat wheels and despite additional energy requirements for ventilators, the potential energy savings are so great that the investment was repaid in just 16 months.

Exhaust Air from Paint Manufacture/Workshop Air

System 12 rotary heat exchangers (RWTs) - rotor diameters from 2150 to 5000 mm
Airflow 900.000 m³/h
Rotor heat recovery 2.740 kW
Production hours per year 6.200 h/a (52Wo x 5T x 24h)
Annual heat recovery 16.988.000 kWh
Gas cost per kWh 0,0329 €/kWh (estimated)
Savings per year 558.905,- €

Additional Costs for Fans in Ventilation System

Volume flow 1 900.000 m³/h
Pressure loss 1 100 Pa
Volume flow 2 900.000 m³/h
Pressure loss 2 159 Pa
Electricity requirement 92,5 kW
Production hours per year 6.200 h
Electricity cost per kWh 0,1395 €/kWh (estimated)
Additional electricity costs 80.003,- €

Additional Costs for Rotor Drive Motor

Rating 0,55 kW
Production hours per year 6.200 h
Additional electricity costs 5.708,- €

Amortisation of Ventilation System Overall

Interest rate used for calculation 4 %
Income from interest per year 22.356,- € from cost savings
Maintenance costs 2.000,- € (estimated)
Estimated investment 625.000,- € (estimated)
Payback period 1.33 years or approx. 16 months

Design and calculation: Klingenburg GmbH