SH | Use of thermostatic valves

EEN Karlsruhe

This measure was implemented within the scope of the Energy Efficiency Network of the City of Karlsruhe (EnergieEffizienz-Netzwerk Karlsruhe).

Project page



Angiomed GmbH & Co. Medizintechnik KG in Karlsruhe has existed for more than thirty years now and has belonged to the American company C.R. BARD Inc. since 1993. The product range stretches from catheters for the specialist fields of radiology, urology and oncology up to stents, of which the production is technologically very complex and which today form the main product group of Angiomed GmbH & Co. Medizintechnik KG. Due to the use of these products on humans, the quality standards are very high.


Angiomed GmbH & Co. Medizin­tech­­­­nik KG
Wachhausstrasse 6
76227 Karlsruhe

+49 (0) 721 / 94 45 0

Contact person
Mr Tara


Title of Measure
Use of thermostatic valves on ceiling air heaters

Brief description
Due to a missing control device, there is a constant stream of air through the heating circuits of the ceiling air heaters all year round, which means that heat is also released into the room when the ventilators are not in operation. The unwanted stream, especially outside the heating period, can be avoided through the use of simple thermostatic valves. The measure was carried out in 2009.

Success record

  • Investment
    €600 – non-recurring
  • Energy carrier(s)
    Fuel oil
  • Annual savings
    Amount of energy: 9.9 MWh
    CO2 emissions: 2 t
    Energy costs: €690
  • Cost effectiveness
    Payback: 0.9 a
    Internal rate of return: 115 %


Copyright notice

This example of ‘Best Practice’ was compiled using images and text with kind permission of the company involved and the project partners. Any reproduction of contents or extracts thereof requires prior written permission by LEEN GmbH.

Calculation basis

The specific parameters shown in the following table have been used to calculate the reduction in CO2 emissions and the savings in energy costs. All details on fuels refer to the calorific value.


Energy carrier Electricity Natural gas Fuel oil District heat Wood pellets
Spec. costs 120 €/MWh 55 €/MWh 70 €/MWh 60 €/MWh 40 €/MWh
Spec. emissions 462 kg/MWh 182 kg/MWh 298 kg/MWh 76 kg/MWh 0 kg/MWh

Evaluation practice

The stated investment does not always take the full costs into account, but often refers here to an avoidable-cost approach. Furthermore, in the case of investments in energy efficiency, mostly only the risk ratio (payback period), but not a profitability ratio such as e.g. the net present value or the internal rate of return are taken into account for the economic evaluation. This practice based solely on the risk ratio leads to a systematic exclusion of profitable investments with an operating life of more than five years and thus systematically to too high energy costs due to excluded profitable rationalisation options. For this reason, the internal rate of return is always given in addition to the payback period for the stated measures.

Internal rate of return vs. payback period

Internal rate of return vs. payback period


Best Practice