Usage Submodels

Overview

The submodels each describe one aspect of room usage or system technology and are bundled in usage profiles or, in the case of surface heatings, assigned directly. This page is the parameter reference of the associated database dialogs; the general operation is described in the Database Concept. Selection lists filled from the internal keyword lists appear with English labels.

Internal loads: People

Databases > Internal loads > People… (dialog “Database of person loads”)

Field	Unit	Meaning
Balancing method	-	Person count, Person per m2, m2 per Person
Maximum number of people	pers., pers./m² or m²/pers.	reference value according to the method
Occupancy schedule	-	schedule 0…1, scales the number of people
Activity schedule	W/pers.	heat emission per person
Schedule for moisture input	kg/pers.	optional; moisture production per person (for the moisture balance), removable again via the delete button
Convective factor	-	convective share of the heat emission (0…1), the rest acts radiatively

Internal loads: Electric equipment

Databases > Internal loads > Electric equipment… (dialog “Database for electric equipment loads”)

Field	Unit	Meaning
Method	-	Power or Power per area; the unit of the power field switches accordingly between W and W/m²
Power	W or W/m²	connected load according to the method
Schedule (“Name of the schedule for managing the power”)	-	utilization degree 0…1
Convective factor, Latent factor, Loss factor	-	distribution of the power: convective, latent, non-room-effective loss

Internal loads: Lighting and Other

Databases > Internal loads > Lighting… (dialog “Database for light loads”) and Databases > Internal loads > Other… (dialog “Database for other loads”) have the same fields as electric equipment, but only the Convective factor (no latent or loss share).

Infiltration

Databases > Ventilation/Infiltration > Infiltration… (dialog “Infiltration database”)

Field	Unit	Meaning
Method	-	normal (constant air change) or n50 (air change at 50 Pa pressure difference)
Air change rate	1/h	hourly air change of the zone air volume
Shielding coefficient	-	editable only with method n50; shielding coefficient per DIN EN 13789

With the method n50, the effective infiltration air change on export to the simulation model is formed from $n_{50} \cdot e$ (air change rate times shielding coefficient).

Natural ventilation

Databases > Ventilation/Infiltration > Natural ventilation… (dialog “Database for natural ventilation”): defines the Air change rate [1/h] and a schedule (Schedule name) that controls the ventilation profile over the day. A preview chart shows the resulting profile.

Control: Thermostat

Databases > Zone-specific controls > Thermostat… (dialog “Zone control thermostat database”)

Field	Unit	Meaning
Method	-	controlled variable: Air temperature or Operative temperature
Controller type	-	Analog (P controller with tolerance band) or Digital (two-point controller)
Schedule of the heating setpoint, Schedule of the cooling setpoint	°C	setpoint profiles from the schedule database; a preview chart shows the heating and cooling curve
Tolerance	K	control tolerance, permissible 0.1…50 K
Pre-heating time	h	lead time of the optimum-start control before the first morning setpoint increase; 0 disables pre-heating, maximum 23 h

Control: Shading

Databases > Zone-specific controls > Shading… (dialog “Zone control shading database”)

• Method: one global horizontal sensor or a horizontal sensor plus four vertical sensors (north, east, south, west). With the pure horizontal variant, the directional fields are disabled.
• Global sensor parameters: threshold irradiation per sensor - Horizontal, North, East, South, West [W/m²].
• Dead band [W/m²]: hysteresis for all sensors. If the irradiation exceeds the threshold, the shading is activated; it is only deactivated when the irradiation falls below the threshold minus the dead band - this prevents frequent switching on and off with fluctuating irradiation.

Control: Natural ventilation

Databases > Zone-specific controls > Natural ventilation… (dialog “Zone control database for natural ventilation”): limits the increased comfort ventilation (e.g. window ventilation in summer).

Field	Unit	Meaning
Maximum comfort air change rate	1/h	upper limit of the comfort air change
Minimum room air temperature / Maximum room air temperature	°C	ventilation stops outside this range
Maximum wind speed	m/s	above this the ventilation stops

Ideal room heating/cooling

Databases > Ideal room heating/cooling… (dialog “Zone ideal heating/cooling database”): limits the power of the ideal conditioning to avoid unrealistic power peaks at setpoint jumps.

• max. heating limit [W/m²]: maximum heating power per square meter of room area; 0 disables heating.
• max. cooling limit [W/m²]: maximum cooling power; 0 disables cooling.

Details on the calculation model: Ideal Heating & Surface Heating.

Surface heatings

Databases > Surface heatings… (dialog “Database for surface heating/cooling systems”)

• Type: Ideal surface conditioning or Water-based surface conditioning (water-carrying pipe register) - selection list with English labels.
• max. heating limit / max. cooling limit [W/m²].
• System parameters (pipe register): Pipe from the pipe database, Pipe spacing [m], Maximum fluid velocity [m/s], Temperature difference between supply and return [K].
• Curves: one table each for Heating and Cooling with two support points (columns Ambient temperature [C] / Supply temperature [C]) - a simple outdoor-temperature-controlled supply temperature curve. The ambient temperatures must increase monotonically, the supply temperature values must differ.

The assignment to surfaces is described in Assigning Surface Heating.

Supply systems

Databases > Supply systems… (dialog “Supply system database”) defines how surface heating circuits are supplied. The Supply type switches the input fields:

Supply type	Inputs
StandAlone	Maximum mass flow [kg/s] and constant Supply temperature [°C]
DatabaseFMU / UserDefinedFMU	Supply FMU (*.fmu file), Maximum mass flow of the FMU [kg/s], Heating power of the FMU [kW]
SubNetwork	supply via a network from the network database

Details on usage: Supply Systems; on FMU coupling: FMU Co-Simulation.

Heating curves

Databases > Heating curves… (dialog “Heating curves database”) describes the supply temperature as a function of the outdoor temperature; a chart shows the resulting curve (with a set temperature difference, also the return temperature). The Type determines the parameters:

Type	Parameters
Constant	Setpoint of the temperature [°C]
Linear function	Minimum/Maximum ambient temperature [°C] with associated setpoints (Setpoint at minimum/maximum ambient temperature); outside the range the respective boundary value is held
Root function	Room temperature [°C], Slope, Offset [K]: $T_{VL} = T_{Raum} + s\,(T_{Raum}-T_{amb})^{1/1{,}3} + \Delta T_{Offset}$ (radiator exponent 1.3 fixed)
User-defined time series by values / by file	time series of the supply temperature, entered directly or from a TSV file

Additionally, the Temperature difference between supply and return [K] can be specified. Heating curves are used primarily on the network and system side (transfer stations, energy centers).

Related topics

• Structure of Usage Profiles
• Schedules
• Assigning Surface Heating
• Internal Loads & Ventilation Calculation Model