2.3.4. Editing the floor heating system<br>

### 2.3.4. Editing the floor heating system

To start editing the floor heating system click on the “Installation” tab in the lower right corner of the screen (during editing of the construction the “Construction” layer is active). The crosshatching inside the rooms disappears and the construction components (rooms, walls, windows, etc.) become inaccessible for editing.

We can distinguish several substages of this stage:

1. Specifying the heating zones.

2. Entering the manifolds and sources.

3. Checking creation of virtual connections and the correctness of connections.

4. Final configuration of data of system components.

Re 1. Specifying the heating zones

The editing of the system should start with the entering of heating zones in the rooms that are to be furnished with floor heating. Select the “Heating zone” component (on the “Radiant” toolbar) and click anywhere within a room to be furnished with floor heating. The HZ is inserted into the room and is represented by a green line enclosing an area. The heating zone is inserted automatically with spacing from the walls maintained in accordance with the settings in the general data of the project (see “Options / General data”).

The heating zone covers the whole area of the room. It is also possible to restrict the HZ to part of the room only. To do this insert a standard heating zone in the room and then press the right mouse button to display the pop-up menu and select “Change type to freely modifiable” and drag the vertexes of the polygon to define the required heating zone.

It is also possible to insert heating zones to all rooms at one time with one click of the mouse. Click on in the “Radiant” toolbar or select “Insert HZ in each room” in the “Edit” menu.

! The program does not check the correctness of the floor structure, whether the individual heating zones are too large or whether they are of proper shape.

! Heating zones should not be divided before calculations are made, even in large rooms. After making the first calculations, information is provided on how many circuits (separate HZ’s) the room should be divided into in order to obtain proper pressure drops, flow rates or in order not to exceed the maximum length of the circuit.

Heating zones have a range of data that can be displayed and amended in the data table. HZ data may be specified immediately after inserting each individual heating zone, or collectively after inserting all HZ’s (see item 4). The use of the F3 (“Repeat last operation”) function key may be very helpful when inserting HZ’s.

Re 2. Entering manifolds and connecting them to the source

After placing HZ’s in all rooms that are to be furnished with floor heating, the appropriate number of manifolds must be provided. After placing a manifold you have to specify its data, because these data have an effect on the possibility of editing connections.

! It is not necessary to specify in the data table the number of outlet ports in the manifold (corresponding to HZ’s), because these will be appended automatically when pipe feeds will be connected to the manifold in the AUTO mode.

If no default type of manifold is specified in general data, you must select one of the available types. Every manifold must be connected to the source by means of pipe-runs. One source may supply several manifolds. If the manifolds are placed on different storeys (and different sheets), remote connections must be made between the sheet with the source and the sheet with the manifold.

Re 3. Checking creation of virtual connections and the correctness of connections

Press the F7 key and go to the general data window and make sure that the “Create virtual connections” box is checked. By default the box is checked, as there is no need to enter pipe feeds at the initial stage of design.

To check the connections within the system press the Shift+F2 key combination (“Check connections”). Connection diagnostics are run and a window is opened with the results presented. If you click a selected message in this window the component to which it applies will be indicated. If there are no messages, that means that all connections have been made properly and there are no components without connection.

Connection checking is not indispensable because errors, if any, will be located during the diagnostic run after calculations are made (see section 2.3.5). Nevertheless it is recommended, as it enables rectifying all errors of this type before proceeding with detailed specification of data of HZ’s and pipe feeds.

Re 4. Final configuration of data of system components

After inserting the system components it is necessary to check and append their data in the table. The data are displayed after marking a component (or several components of the same type).

Heating zone data

To mark a heating zone click on the rectangle describing the given HZ – this facilitates marking feed lines or other components within the heating zone.

As was the case with rooms, most of the data here is also assigned by default. However, data that differ from the default values have to be entered by the user. Most important data include type of floor covering and temperature below room. If the temperature below room has been specified at the construction level, then it will be displayed on the Installation layer without possibility to change it. Temperature below room may vary for different HZ’s within the same room. This way you can handle for instance a room, part of which is situated over a basement, while its remaining part lies on ground. In this case enter “-“ in the “ti/qi below” field on the “Construction” layer. Then it will be possible to edit temperature below room in HZ data after drawing one or more HZ’s.

! Specifying a temperature below for a given HZ which differs significantly from other temperatures below room may result in the increase or decrease of the thickness of heating zone structure (an offset between HZ’s).

The type of floor covering determines its thermal resistance and has a significant effect on calculation results. If there are no instructions on the covering to be used, then the most favourable of the available types or the standard value of 0.1 should be specified.

Heating zone symbol and room temperature are determined on the basis of room data. HZ symbol can be changed for every HZ, whereas in order to change the room temperature you must select the “Construction” tab and change the relevant data of the room with the HZ in question.

Attention should be paid to the field for determining type of heating zone. This field enables specifying a specific type of heating zone – a HZ heated by pipe feeds. Such zone will not be linked to a manifold, and the heat loss assigned to it will be covered, as much as possible, by heat from pipe feeds linked to other HZ’s. The need to have such a type of HZ results from the fact that many data items, such as type of floor covering, insulation layer, pipe fastening type and other, are necessary to calculate the heating capacity of pipe feeds.

The “Effective area” indicates the effective heating zone area of given HZ determined by the application. This value is lower (sometimes much lower) than the area within wall faces for the given HZ because the strips along walls, which are not covered by floor heating, and occupied area (e.g. by furniture) are deducted.

In some cases peripheral zones can be defined. A peripheral zone consists of part of or the whole HZ with increased maximum permissible floor temperature. During automatic distribution of heat losses among HZ’s in a room it ensures higher output from a square metre of surface in peripheral zones. You can introduce PZ before first calculations are made, in order to deliver more heat, for instance, near glazed walls, or later, to increase heat output in underheated rooms. Three different structural solutions of the peripheral zone are available:

- The entire HZ is defined as a PZ (symbol sPZ). Should be used when the area of PZ is large. This is an advantageous solution as it ensures other operating parameters of the PZ in relation to OZ (other temperature difference), thus enabling substantial increase of output per square metre with the same supply temperature. It also facilitates hydraulic control.

- Part of HZ constitutes a peripheral zone formed by compacting the pipe arrangement (symbol cPZ). This solution enables slight increase of heat output in the peripheral zone because the mean temperature of the heating medium in PZ and OZ is in this case the same and the congestion of pipe arrangement produces a moderate effect.

- Part of HZ constitutes a peripheral zone, and it is the initial (upstream) part of the heating circuit (symbol uPZ). As in the case of cPZ, pipe layout is congested. The heating medium flows through the PZ first and then flows to the. This solution ensures much higher heat output in the peripheral zone than the cPZ option. It can also be applied when a given pipe pattern (pipe spacing) causes the maximum floor temperature to be exceeded and is therefore not applicable. Introduction of an integrated PZ at the start of the circuit cools down the heating medium in the area where the maximum floor temperature can be higher and ensures that the limit value is not exceeded in the occupied zone.

! In the case of a single pipe meander pattern the compacted peripheral zone is not available, as the compacted part of the heating circuit forms the beginning of the circuit and it is therefore a peripheral zone of the uPZ type.
The cPZ type is available for those pipe pattern options where the supply and return parts are arranged alternately – that is the double meander and spiral patterns.

In the “Floor structure” field you can specify a covering and insulation other than the default type or you can specify individual insulation layers.

Individual specification of HZ data is controlled by the “General standard data” field. After changing the value in the field to “No”, you can change the default manner of pipe fastening, type and diameter of pipe, permissible pipe spacing and permissible range of temperature difference, separately for PZ and OZ.

Manifold data

Minimum and maximum temperature drop of the medium, “Dt/Dq min” and “Dt/Dq max” respectively, specified individually for the occupied and peripheral zones, and permissible flow resistance of each connected circuit (“MaxDeltaP”), have significant effect on the calculations. Note that manifold valves are fittings that are assigned to the manifold and selection of supply and return valves is done in the manifold data table.