Question-and-Answer Resource for the Building Energy Modeling Community
Get started with the Help page
Ask Your Question

Revision history [back]

click to hide/show revision 1
initial version

Heating/Cooling controlled by BoilerOutlet Temperature - No Thermostat

Goal: I am working on an energy plus simulation setup that controlls a space's temperature based on the Boiler Outlet Temperature like this:

  • Hot Water e.g. 90°C-> increase in Room Temperature
  • Cooler Water e.g. 23°C -> Room Temperature stays

Status: So far I have only found building files using a Thermostat which somehow seems to ruin my idea as it takes over controll and regulates the temperature (as it is intented actually). I also tried setting the dual setpoint limits very low/high so I can control the temperature inbetween but even though the Boiler Outlet Temperature is controlled well, it is not reflected in the rooms temperature. Outside Air Ventilation, Coil Energy, etc. probably takes over which I could not figure out easily at this point.

Also, I get Warnings leading me to the believe that something is not correctly set up:

** Warning ** Calculated design cooling load for zone=SPACE1-1 is zero.
**   ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.
** Warning ** Calculated design heating load for zone=SPACE1-1 is zero.
**   ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.
    .
    .
    .
** Severe  ** Data Exchange API: Index error in getVariableValue; received handle: -1
**   ~~~   ** The getVariableValue function will return 0 for now to allow the plugin to finish, then EnergyPlus will abort

I am currently using the HVACTemplate-5ZoneBaseboardHeat.idf building file.

In the building file I changed the Setpointmanager:AirReset to a SetpointManager:Scheduled to controll the boiler temperature with a schedule.

Question: Is this a suitable building file to achieve my goal, even though there is a Thermostat? Or is there a simplier Building file with a Boiler->Baseboard Heater circuit where I can control heating by Boiler Outlet Temperature?

Heating/Cooling controlled by BoilerOutlet Temperature - No Thermostat

Goal: I am working on an energy plus simulation setup that controlls a space's temperature based on the Boiler Outlet Temperature like this:

  • Hot Water e.g. 90°C-> increase in Room Temperature
  • Cooler Water e.g. 23°C -> Room Temperature stays

Status: So far I have only found building files using a Thermostat which somehow seems to ruin my idea as it takes over controll and regulates the temperature (as it is intented actually). I also tried setting the dual setpoint limits very low/high so I can control the temperature inbetween but even though the Boiler Outlet Temperature is controlled well, it is not reflected in the rooms temperature. Outside Air Ventilation, Coil Energy, etc. probably takes over which I could not figure out easily at this point.

Also, I get Warnings leading me to the believe that something is not correctly set up:

** Warning ** Calculated design cooling load for zone=SPACE1-1 is zero.
**   ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.
** Warning ** Calculated design heating load for zone=SPACE1-1 is zero.
**   ~~~   ** Check Sizing:Zone and ZoneControl:Thermostat inputs.
    .
    .
    .
** Severe  ** Data Exchange API: Index error in getVariableValue; received handle: -1
**   ~~~   ** The getVariableValue function will return 0 for now to allow the plugin to finish, then EnergyPlus will abort

I am currently using the HVACTemplate-5ZoneBaseboardHeat.idf building file.

In the building file I changed the Setpointmanager:AirReset to a SetpointManager:Scheduled to controll the boiler temperature with a schedule.

Question: Is this a suitable building file to achieve my goal, even though there is a Thermostat? Or is there a simplier Building file with a Boiler->Baseboard Heater circuit where I can control heating by Boiler Outlet Temperature?