Interactive calculations of radiant systems
|Type of article||FUNCTION AND TOOL|
|Source for translation||2022-08-25|
Interactive radiant systems calculations enables fast manual adjustment of selected parameters of a radiant system in given application (Heating/Cooling). In the Interactive radiant systems calculations window the following can be adjusted:
- the value of Pipe spacing,
- the value of Temp. diff. supply-return
- the value of No. of H/C Areas,
- the value of θs,H rad for selected control circuits in a heating system,
- the value of θs,C rad for selected control circuits in a cooling system.
After modifying the value of:
- Pipe spacing
- No. of H/C Areas
- θs,H rad / θs,C rad
it is necessary to click the Calculate button to verify the effects of the changes made on calculation results. The calculations are carried out only in part within the scope covering only the radiant systems. In the interactive calculation phase, the pressure drops and settings on the control valves/rotameters on the manifold are determined on the assumption that the pressure upstream of the manifold has the value of the required minimum available pressure for this manifold. Once the window is closed and the full calculation of the heating/cooling systems has been carried out, pressure drops and setpoints are redetermined because the hydraulic calculation of the entire system is carried out, as a result of which the pressure upstream of a given manifold may be higher than the minimum required.
In the case of a change of the Temp. diff. supply-return value it is not necessary to click the Calculate button, parameters are updated constantly.
After closing the Interactive radiant systems calculations window a full calculation of the heating/cooling systems must be carried out, as the project is in a non-calculated status, which is indicated, among other things, by a message on the status bar:
Attention! The project has not been calculated or data have been modifed since last calculation.
Location in the program
- The Interactive radiant systems calculations icon is available in the Main tools bar in section Calculations.
- Keyboard shortcut: Ctrl + Shift + F10.
Examples of use
Which scopes are available for Interactive radiant systems calculations and which windows are editable depends on the selected use of source.
- Heating use - in the Interactive radiant systems calculations window it is possible to modify parameters in the Heating tab, the Cooling tab is empty.
- Heating and cooling efficiency use - in the Interactive radiant systems calculations window it is possible to modify parameters in the Heating tab, the Cooling tab displays all values, but these cannot be modified.
- Cooling use - in the Interactive radiant systems calculations window it is possible to modify parameters in the Cooling tab, the Heating tab is empty.
Other possibilities in the Interactive radiant systems calculations window
- Filtering Heating/Cooling Zone connected to given manifold.
- The display/hiding of Heating/cooling floor components of the Heated/cooled by pipe feeds and Without pipes types is possible with the use of the Show also "Zones heated by feed pipes or with no pipes" checkbox.
- Restoration of automatic calculation settings - Restore AUTO settings.
Selecting the method of presenting manifolds
The Show tree according to field enables the management of the methods of presenting manifolds, with the following options available:
- Building structure - Double apartment manifold components are displayed in a tree in the order consistent with their presence on subsequent floors and within the building unit to which they are assigned.
- Control circuits - Double apartment manifold components are arranged in groups with control circuits of the same supply temperature.
Modifying the supply temperature in a control circuit
To change the supply temperature for a selected control circuit one of the following must be done:
- Enter the value for the circuit in the θs,H rad field.
- Check the Optimize box.
- Switch the status of the field into the AUTO mode (calculator icon), so that the manner of determining the values for θs,H rad is consistent with the settings in the General data window in section Thermal systems/ Sources, and then press the Calculate button.
Adjustment of the number of Heating/Cooling Areas
- When the number of H/C Areas is changed manually, the default values of Temp. diff. supply-return (computer status) are restored for all H/C Areas belonging to given H/C Areas Zone.
Adjustment value of Pipe spacing
- As a result of manual adjustment of Pipe spacing the program can change the value of Heating-cooling surface, but the automatic mode of Heating/Cooling Zone division is not disabled.
Change in the value of Pipe spacing in a single Heating-cooling surface changes that parameter in all H/C Area elements present within the common Heating/Cooling Zone.
Display of the balancing valve setting and of the covering
- The selected covering is displayed in the Interactive radiant systems calculations window.
- The field Valve setting is displayed with a value in the Interactive radiant systems calculations window.
Adjustment of Temp. diff. supply-return
- Modification of this value may, among other things, have an effect on the elimination of the diagnostics message:
- water velocity in pipe not sufficient for self-venting.
If the Temp. diff. supply-return value is modified, it is not necessary to click the Calculate button.
Take vmin into account
The minimum flow velocity in a pipe (v_min) can be taken into account in calculations when the Minimum velocity box is checked on the respective tab in the General data window (Floor systems / Wall systems / Ceiling systems). In the AUTO mode the intial value for the selected pipe type is taken from the catalog of the selected system.
The consequence of adjusting parameters in Interactive radiant systems calculations is the rejection of the option of optimum supply temperature determination in a radiant system according to the criterion selected in General data:
- heat output and press. drop,
- min. investment costs.
This rejection is indicated by the program with diagnostics messages at the hint level:
- there is a better spacing in heat output terms than the one specified,
- there is a better spacing in cost terms than the one specified,
- there is a better spacing in heat output and flow terms than the one specified.
The list of diagnostics messages in the Interactive radiant systems calculations window may differ from that in the Diagnostics window. Any adjustments in the design should be based on the list of messages created after calculations are made for the appropriate scope of the design, e.g. Heating and cooling systems, that is in the Diagnostics window.
Rules of highlighting the fields which are editable in the calculations window:
- Changing a value in a field causes the cell to be highlighted with another colour and presentation of that value.
- No colour highlighting after completed calculation.