# 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.

## 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*;- 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*.

### 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; - 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*;- 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*.

### 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*.

### 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.

**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*and_{conv,H}*Not utilized heat loss of pipe-runs*; - 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*.