Question-and-Answer Resource for the Building Energy Modeling Community
Get s tarted with the Help page
Ask Your Question
2

How to set a deadband so while the zone air temperature is between 22 and 26°C the heating system is off.Am using designbuilder so maybe I can do this through an EMS file

asked 2016-10-19 07:16:41 -0600

updated 2016-10-20 07:42:02 -0600

edit retag flag offensive close merge delete

Comments

Are 22C and 26C your heating and cooling setpoints?

pflaumingo gravatar image pflaumingo  ( 2016-10-19 09:39:21 -0600 )edit

I said the ELSEIF doesn't make sense because if the TSTAT turns on the heater when AptTemp < hSP (the ELSE), then you only want it to turn off when AprTemp > hSP+Toffset. I believe your EMS prog will turn off the heater as soon as AptTemp> hSP. I see now the ELSEIF is meant to hold off heating while the space floats back down to hSP. What about when the heater is on while space is moving toward hSP+Toffset? The IF will turn it off at hSP.

rraustad gravatar image rraustad  ( 2016-10-19 11:59:06 -0600 )edit

Hi, Thanks for commenting I have no cooling system i just want to maintain a temp. of 22-26 inside the room. Your Help is Appreciated

designbuilderknowledge gravatar image designbuilderknowledge  ( 2016-10-20 01:58:48 -0600 )edit

2 Answers

Sort by » oldest newest most voted
1

answered 2016-10-19 10:03:11 -0600

updated 2016-10-19 12:01:14 -0600

The ELSEIF doesn't make sense. If AvailSCH_Overwrite = 0 && something else, SET AvailSCH_Overwrite = 0 ??

IF AptTemp > (hSP), SET AvailSCH_Overwrite = 0,
ELSEIF AvailSCH_Overwrite == 0 && AptTemp >= (hSP) && AptTemp <= (hSP + Toffset), SET AvailSCH_Overwrite = 0,
ELSE, SET AvailSCH_Overwrite = 1, ENDIF

The program should instead do:

IF AvailSCH_Overwrite == 0 && AptTemp < (hSP), SET AvailSCHOverwrite == 1,
ELSEIF AvailSCH_Overwrite == 1 && AptTemp > (hSP+Toffset), SET AvailSCHOverwrite == 0,
ELSE SET AvailSCHOverwrite == NULL;
edit flag offensive delete link more

Comments

Thank you very much your comment is right but am still getting errors any idea why?

designbuilderknowledge gravatar image designbuilderknowledge  ( 2016-10-20 02:42:22 -0600 )edit
1

answered 2016-10-20 08:48:08 -0600

Ivan Korolija gravatar image

If this question is related to the linked one than you need first to set the heating setpoint to 26C and an EMS control logic will be similar to the code desribred here

This is the code which should work in your case

Schedule:Constant,Cycle,OnOff,1; ! New schedule object

AvailabilityManager:Scheduled, ! Updated Availability Manager
  Packaged Rooftop Air Conditioner Availability Manager, 
  Cycle;

EnergyManagementSystem:Sensor,
  AptTemp,
  BLOCK1:ZONE1,
  Zone Mean Air Temperature;

! Don't forget to set heating setpoint to 26C
EnergyManagementSystem:Sensor,
  hSP,
  BLOCK1:ZONE1,
  Zone Thermostat Heating Setpoint Temperature;

EnergyManagementSystem:Actuator,
  AvailSCH_Overwrite,
  Cycle,
  Schedule:Constant,
  Schedule Value;

EnergyManagementSystem:ProgramCallingManager,
  Supervision,
  BeginTimestepBeforePredictor,
  HVAC_uncontolledloop_Supervision;

EnergyManagementSystem:Program,
  HVAC_uncontolledloop_Supervision,
  SET Toffset = 4,
  IF AptTemp > (hSP - 0.01), ! -0.01 due to system can maintain the zone temperature very close to the setpoint
  SET AvailSCH_Overwrite = 0,
  ELSEIF AvailSCH_Overwrite == 0 && AptTemp >= (hSP - Toffset),
  SET AvailSCH_Overwrite = 0,
  ELSE,
  SET AvailSCH_Overwrite = 1,
  ENDIF;
edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

 

Question Tools

1 follower

Stats

Asked: 2016-10-19 07:16:41 -0600

Seen: 611 times

Last updated: Oct 20 '16