1.3 Centralized Heat Pump System for the Whole Building

Heat distribution and temperatures levels

Separate production of space heating and DHW. The heat pump providing exclusively space heating may be optimized for this purpose. In case of an underfloor heating system, temperature required is significantly lower than for DHW. 

Size of building, number of apartments

For all sizes of buildings, but often used for bigger buildings. For smaller and average buildings there is less need for bivalent systems.

DHW and storage characteristic

Fossil or biomass heat generator can easily provide high DHW temperatures, avoiding the problem of legionella. Storage tank is recommended to provide reliability of the system and to allow for a more stable operation of the fossil generator.

Energy standard, insulation level 

More applicable for older, not refurbished buildings with a higher heating energy demand. This solution is generally not to be recommend for new buildings due to the use of fossil energy sources. It can be a practicable solution if the investor wishes to exchange only one of the existing heat generators.

Complexity of installation

In case of retrofitting, exchanging only one mode may reduce the complexity of the planned construction work.

Heat Sources

All heat sources possible. The possibility to cover only heating demand with the heat pump, without the DHW, may be beneficial if the heat source for the heat pump is limited.  

Specific issues of the concept

The heat distribution of both functions (space heating In case of retrofitting, this solution allows for exchange of only one heat generator towards to complete “heat pump only” solution in the second time step. 

Positive aspects

• Interim solution for larger MFB’s in a phased approach
• Easy legionella prevention

Negative aspects

• High distribution losses
• Partial use of fossil fuel