3.4.5. “Radiant heating” tab<br>

### 3.4.5. “Radiant heating” tab

The “Radiant heating” tab consists of three sub-tabs where the most important data on floor and wall heating are specified.

“Radiant heating - general data” sub-tab

This sub-tab is provided for specifying data applying to both floor and wall heating at the same time. These include:

- “Default manifold type”, “Default distribution header cabinet type” – specify default settings for manifolds in the project.

- “Dt/Dq min OZ”, “Dt/Dq max OZ”, “Dt/Dq min PZ”, “Dt/Dq max PZ” – specify the permissible range of temperature difference between the supply and return sides (cooling of the heating medium) in heating circuits, separately for occupied and peripheral zones. Default settings are consistent with manufacturer’s guidelines. Note that changing the temperature difference in the circuit, which converts directly the flow rate of the medium and its mean temperature, is the basic means of adapting the floor heat output to the required value. Therefore a narrow range of permissible temperature drop makes sizing more difficult. On the other hand, if a system must be designed to match a defined temperature drop, it can be specified here by entering the same value for Dt/Dq min and Dt/Dq max..

- “Max. press. drop in circuit [kPa]” – enables changing the default maximum pressure drop in heating circuit (linear drop across the pipe and pipe fittings). Maximum value that can be entered is 50 kPa.

In the bottom part of the window there is a “Max. length of pipes” button which opens a window where you can change the standard restrictions on maximum length of the heating circuit. Default settings correspond to the manufacturer’s guidelines and in most cases to commercial lengths of coiled pipe of the given type. There is also the maximum value, which corresponds to maximum length of pipe that can be purchased. There may also be a situation where the default length is the maximum length available.

“Floor heating” sub-tab

This sub-tab holds the most important data on the floor heating system applied and on default settings. Adequate configuration of the fields in this tab may facilitate entering of the data and filling in of some of these fields is imperative.

- “Manufacturer” – must be filled in. In case of firmware version of the program the manufacturer is selected by default.

- “Default system / fastening method” – indicates which system will be applied in the project most often and will constitute the default system for new heating zones.

- “Default pipe type” – indicates which pipe type, from among those offered by the manufacturer, will be the default type in the system designed.

- “Heat transfer coefficient of screed” – enables changing the default heat transfer coefficient of screed, when the one applied in the project is different. Permissible range of values is between 0.1 to 0.2 W/(m K).

- “Available spacing in OZ” – enables unchecking one or more pipe spacing values in the occupied zone. By default all pipe spacing values permitted by the selected fastening system and by the selected pipe type are marked.

- “Available spacing in PZ” – enables checking/unchecking one or more pipe spacing values in the peripheral zone. By default the values recommended by the selected manufacturer are marked.

- “Dist. between HZ and ext. wall” and “Dist. between HZ and int. wall”.

- “Dist. between HZ and ext. wall” and “Dist. between HZ and int. wall” – will be taken into account when heating zone is inserted into the rooms when editing the heating system. The inserted heating zone is automatically spread over the entire area of the room with a defined spacing from walls. Note, however, that this is a conventional boundary of HZ, meant as the distance between the outermost pipe plus half of pipe spacing. For instance, if the pipe spacing is 20 cm and the distance of HZ to the wall is 15 cm, then the outermost pipe should run 25 cm from the wall (15 + ½ * 20). The spacing has no effect on the physical size of the heating slab, which always reaches the wall. It has, however, an effect on the effective area of HZ. Neglecting the distance to the wall during design and taking it into account when forming the circuit may lead to serious errors: in a room with surface area of 20 m2 the rejection of a 15 cm wide band along the walls reduces the heated area by ca. 2.5 m2, which corresponds to ca. 13% of the area of the heating slab.

- “Default covering” – enables specification of default covering for heating surfaces. Default covering will be assigned to those HZ’s, which have no other covering specified in their data tables.

- “Automation system” – optional field – enables selection of an automatic system for controlling the floor heating system in the current project from among those offered by the manufacturer.

- “Default room thermostat” – optional field – depending on the selected automatic control system, a default type of thermostat may be specified for the rooms.

- “Default usage of passing pipe feeds heat output [%]” – specify the percentage of heat output of pipe feeds. The default value is 90%.

- “Default max. load [kN]” – specify maximum permissible load for heating floors – determines structure.

- “Default ti/qi below for current worksheet [°C]” – specify default temperature below heated rooms. Required for automatic or manual determination of floor structure. You can specify different temperatures for individual storeys, provided that they are on separate sheets.

! It is not possible to select default types if the manufacturer of the floor heating system is not specified

“Wall heating” sub-tab

This sub-tab holds the most important data on the wall heating system in the project. These include:

- “Manufacturer” – must be filled in. In case of firmware version of the program the manufacturer is selected by default.

- “Default system / fastening method” – indicates which system will be applied in the project most often and will constitute the default system for new heating zones.

- “Default pipe type” – indicates which pipe type, from among those offered by the manufacturer, will be the default type in the system designed.

- “Available spacing:” – enables checking/unchecking one or more pipe spacing. By default all pipe spacing values permitted by the selected fastening system and by the selected pipe type are marked.

- “Heat transfer coefficient of plaster” – enables changing the default heat transfer coefficient of plaster, when the one applied in the project is different. Permissible range of values is between 0.1 to 0.2 W/(m K).

! It is not possible to select default types if the manufacturer of the wall heating system is not specified