Heating installations
Efficiency numbers for existing systems
Efficiency numbers depend from both the technology of a heating system and its actual operation. In determining efficiency numbers theoretically an ideal operation is assumed. In existing systems operation usually has major impacts. Therefor efficiency numbers can only be estimated. This was done for typical systems:

Anyway measures
Heating systems are restricted in their lifetime. It is recommended to replace components after their expected useful life (Anyway measures)

Retrofit measures
Basically we have identified 3 classes of measures. They include
1. Adaption of system to actual demand
2. Replacement of heat generation part
3. Control of system operation
The first class of measures will modify the efficiency number to its theoretical value
The second class of measures requires some investments which however has a short payback time.
The third class of measures is the basis of proper operation and will make the achievements of the first two measures sustainable