Heat source dimensioning

Product	InstalSystem 5
Type of article	TIP&TRICK
Source for translation	2022-12-14

Problem description

The way in which the heat source is dimensioned depends on the type of designed installation and on the Method of calculating Φ specified in the General data window.

1. Method of calculating Φ selection.

Solution

Heating installations without Flat stations

For dimensioning the heat source the following values should be taken into account:

• Design heat load of building – in the case when thermal calculations of a building based on Calculations acc. to standard;
  

  

  2. Design heat load of building for the installations without Flat stations.

  
  
• the total value of: Spec. total rooms heat loss Φ_H, Not utilized heat loss of pipe-runs and Losses of radiant systems to outside of source feed area - in the case when thermal calculations of a building based on Calculated acc. to coefficient or User specified.
  

  

  3. Spec. total rooms heat loss Φ_H for the installations without Flat stations.

  
  

4. Not utilized heat loss of pipe-runs and Losses of radiant systems to outside of source feed area for the installations without Flat stations.

Heating installations with Flat stations

For such type of installations there are two variants for the heat source dimensioning in the heating period:

• if the heat source lacks a buffer tank - heat source dimensioning should adopt the Total output value;
  

  

  5. Total output for the installations with Flat stations.

  
  
• if the heat source includes a buffer tank - the indicated Total output value is the peak power that the buffer tank is supposed to deliver to the installation. For dimensioning the heat source the following values should be taken into account:
  • Design heat load of building – in the case when thermal calculations of a building based on Calculations acc. to standard;
    

    

    6. Design heat load of building for the installations with Flat stations.

    
    
  • the total value of: Spec. total rooms heat loss Φ_H, Not utilized heat loss of pipe-runs and Losses of radiant systems to outside of source feed area - in the case when thermal calculations of a building based on Calculated acc. to coefficient or User specified.
    

    

    7. Spec. total rooms heat loss Φ_H for the installations with Flat stations.

    
    

    

    8. Not utilized heat loss of pipe-runs and Losses of radiant systems to outside of source feed area for the installations with Flat stations.

    
    

Total output of heat exchangers in flat stations in summer

In summer period, when the flat stations are operating in DHW heating mode, the heating capacity ordered from the heat source can be reduced. The value of Total output of heat exchangers in flat stations in summer can be found in the General results heating.

9. Total output of heat exchangers in flat stations in summer.

The difference between the Heat quantity carried by pipe-run on the first section from the heat source and Total output of the heat source

There is a difference between the values of Heat quantity carried by pipe-run on the first section from the heat source and Total output of the heat source based on the results of the heating system calculations. The reason is in the different methods of calculation.

Heat quantity carried by pipe-run of the first section is calculated from required output of the heating system and it is summarized sequentially by pipe sections.

10. Heat quantity carried by pipe-run on the first section from the heat source.

ATTENTION! The value of the Heat quantity carried by pipe-run is for information only.

Total output of the heat source includes:

• for Convectional heating systems - Total output of convectors Φ_conv,H and Not utilized heat loss of pipe-runs;
  

  

  11. Total output for Convectional heating systems.

  
  
• for Radiant heating systems - Total output of radiant heaters Φ_rh,H, Not utilized heat loss of pipe-runs and Losses of radiant systems to outside of source feed area.
  

  

  12. Total output for Radiant heating systems.