Control strategies

trano controls every heated room with a PI loop on the air temperature, whose set point a schedule switches between an occupied value and a setback value (see How ifctrano works). By default the rooms are heated to 21 °C from 7:00 to 19:00 and to 15.85 °C at night. The configuration written by ifctrano can be edited to change this; this example compares the default night setback with a constant set point, on ExampleHOM with its heating model.

Write the configuration:

ifctrano config ExampleHOM.ifc --hvac ExampleHOM_heating.ifc

and set the setback temperature to the set point in the emission control of each space:

spaces:
- id: space_living1_v3g
  emissions:
  - radiator:
      id: radiator_space_living1_v3g
      parameters:
        nominal_heating_power_positive_for_heating: 3360.0
  - valve:
      id: valve_space_living1_v3g
      control:
        emission_control:
          id: emission_control_space_living1_v3g
          parameters:
            temperature_heating_setback: 294.15

then build (and simulate) the model from the edited configuration:

ifctrano from-config ExampleHOM.yaml --simulate-model

The other parameters of the emission control are temperature_heating_setpoint (294.15 K), schedule (3600*{7, 19}, the switching times in seconds of the day) and controller_gain (5).

Days 3 to 10 of the year (the first 2 simulated days are a warm-up and are left out).

Case	Zone	Mean [°C]	Minimum [°C]	Maximum [°C]	Radiator heat [kWh]	Peak radiator heat [kW]	Heat from the generator [kWh]	Gas [kWh]
Night setback (default)	Living1	18.6	15.0	21.8	125	4.4	148	190
Constant set point	Living1	20.9	19.9	22.0	162	1.6	183	229

What to expect. With the night setback, the rooms cool down at night and are heated up again at 7:00, which takes a power peak; with a constant set point the rooms stay at 21 °C and the radiators deliver a steadier, higher heat.

What the simulation shows. Over days 3 to 10, the living room averages 18.6 °C with the night setback (15.0 °C at night) and 20.9 °C with the constant set point (never below 19.9 °C). Keeping the house at 21 °C needs 162 kWh of radiator heat instead of 125 kWh (30 % more) and 229 kWh of gas instead of 190 kWh (21 % more). The peak heat is lower with the constant set point, 1.6 kW instead of 4.4 kW: the night setback saves energy but asks for a morning reheat.