DualSetPointWithDeadBand severe error pls help..

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jamo0312see
Posts: 84

DualSetPointWithDeadBand severe error pls help..

Postby jamo0312see » Thu Apr 12, 2012 4:36 pm

** Severe ** DualSetPointWithDeadBand: Effective heating set-point higher than effective cooling set-point - increase deadband if using unmixed air model
** ~~~ ** occurs in Zone=GRNDFLRCLNGVD:BMS During Warmup & Sizing, Environment=WINTER DESIGN DAY IN ADGT


what does this mean?
jessica.holz@umowlai.com.
Posts: 3

Postby jessica.holz@umowlai.com. » Wed Jul 18, 2012 12:25 am

Hi,
Did you work this error out?

I've been getting the same error. I am going to try to widen the difference between the heating setpoint (was 20 degrees, now 19 degrees) and the cooling setpoint (was 23 degrees, now 234 degrees). I'll let you know if it works.

Cheers.
jlong
Posts: 25

Postby jlong » Wed Jul 25, 2012 8:42 am

have you tried downloading the latest beta version?
Regards

James
jessica.holz@umowlai.com.
Posts: 3

Scheduling

Postby jessica.holz@umowlai.com. » Wed Jul 25, 2012 10:50 pm

Hi James, no I haven't but I will do that.

I resolved this error. It occurred because I had on/off (fraction) scheduling in my temperature setpoints for the zone temperature instead of temperature scheduling. Simple mistake for new players.

Jessica
xbushyx
Posts: 4

Error:DualSetPointWithDeadBand

Postby xbushyx » Thu Oct 03, 2013 9:07 am

I m having a similar error as follows

************* Construction=DOUBLE PAN WINDOW
** Severe ** DualSetPointWithDeadBand: Effective heating set-point higher than effective cooling set-point - increase deadband if using unmixed air model
** ~~~ ** occurs in Zone=ZONE ONE During Warmup, Environment=SINGAPORE, at Simulation time=09/24 00:00 - 00:10

I m not using any temperature scheduling just heating and cooling setpoints for the thermostat @ 26 & 24 degC respectively.

Could anybody help me with this?

Also, as i m running a simulation for Singapore (tropical country) where there is no need for boilers in HVAC systems, is there a way i can run EP with for HVAC fancoil units without including boilers in the input? i tried excluding it but it came out with a severe error.

many thanks!
Luis Sousa
Posts: 367
Location: Stroud

Postby Luis Sousa » Fri Oct 04, 2013 5:36 pm

Hi,

This error is generated because the Heating setpoint temperature (26degC) is higher than the Cooling setpoint temp (24degC).
You should assign the lower temperature to the Heating setpoint.

Cheers,
MEHRNAZ
Posts: 6

Postby MEHRNAZ » Thu Sep 10, 2015 7:26 am

I have the same problem ;
** Severe ** DualSetPointWithDeadBand: Effective heating set-point higher than effective cooling set-point - increase deadband if using unmixed air model
** ~~~ ** occurs in Zone=RDC During Warmup & Sizing, Environment=SUMMER DESIGN DAY IN JULL

I have cheked the set points in activity tab and cooling set point is lower;
I have written in schdualing zone set point with temperature and not fraction but I have still the problem;

Thank you for your help
Luis Sousa
Posts: 367
Location: Stroud

Postby Luis Sousa » Thu Sep 10, 2015 8:11 am

I have cheked the set points in activity tab and cooling set point is lower;


The zone Cooling set point temperature has to be higher (normally it's 2 degC difference).

Setting the zone Cooling set point temperature lower than the Heating temperature will raise problems with the HVAC control where the HVAC system will try (and fail) to met both set points on the same time step.

BR,
MEHRNAZ
Posts: 6

Postby MEHRNAZ » Thu Sep 10, 2015 8:22 am

I'm sorry but I made a mistake, I wanted to tell the cooling setpoint is higher and I have this problem yet.

heating set points are 19 and 16
cooling set points are 26 and 30
MEHRNAZ
Posts: 6

Postby MEHRNAZ » Thu Sep 10, 2015 8:32 am

and these are my scheduling for heating and cooling

Heating

SCHEDULE:COMPACT,
RDC,
Temperature,
Through: 15 May,
For: AllDays,
Until: 24:00, 0,
Through: 15 Oct,
For: Monday Tuesday Wednesday Thursday Friday Holidays WinterDesignDay,
Until: 05:00, 0.5,
Until: 19:00, 1,
Until: 24:00, 0. 5,
For: Weekends AllOtherDays,
Until: 24:00, 0. 5,
Through: 31 Dec,
For: Monday Tuesday Wednesday Thursday Friday Holidays,
Until: 05:00, 0. 5,
Until: 19:00, 1,
Until: 24:00, 0. 5,
For: Weekends AllOtherDays,
Until: 24:00, 0. 5;


cooling :

SCHEDULE:COMPACT,
Cooling_off,
Temperature,
Through: 12/31,
For: SummerDesignDay,
Until: 24:00, 0,
For: AllOtherDays,
Until: 24:00, 0;

because I dont have cooling in my project but I should take the setpoints in activity tab and I wrote the temperatures in previous post
Luis Sousa
Posts: 367
Location: Stroud

Postby Luis Sousa » Thu Sep 10, 2015 9:44 am

Hi,

I was unable to reproduce the problem using a simple model.

Could you submit a ticket at DB Helpdesk ( www.designbuilder.co.uk/supportdesk)

and attach your model.

Thanks,
LS
MEHRNAZ
Posts: 6

Postby MEHRNAZ » Thu Sep 10, 2015 10:58 am

I did it

Thanks
Luis Sousa
Posts: 367
Location: Stroud

Postby Luis Sousa » Fri Sep 11, 2015 9:40 am

Hi,

Just to add that if you are using Detailed HVAC with option '2-Detailed HVAC Data' then you will need to check the temperatures set at the schedules that are assigned to the zone at HVAC Zone.

Regards,
MEHRNAZ
Posts: 6

Postby MEHRNAZ » Fri Sep 11, 2015 10:13 am

Hi

Thank you so much for your help.
In fact, I corrected my mistake.
I put the tempretures 19 and 16 in my 'Thermostat heating setpoint schedule'. and the error left but now I have the warning who tel me that the heating load in the zones is zero!

More, I have an error for economy analyse currenty but I didnt choose cost analyse in building tab!
vosiman
Posts: 2

Re: DualSetPointWithDeadBand severe error pls help..

Postby vosiman » Tue Mar 26, 2019 2:17 pm

Hi,
my building has Induction units and 2 big AHUs. I have a similar problem. I can´t go through simulation because of this error:

** Severe ** DualSetPointWithDeadBand: Unanticipated combination of heating and cooling loads - report to EnergyPlus Development Team
** ~~~ ** occurs in Zone=B3X5NP:OFFICE Environment=RIVER CITY_KARLIN (01-01:31-12), at Simulation time=02/15 14:15 - 14:18
** ~~~ ** LoadToHeatingSetPoint=NAN, LoadToCoolingSetPoint=NAN
** ~~~ ** Zone Heating Set-point=22.00
** ~~~ ** Zone Cooling Set-point=24.00
** ~~~ ** Zone TempDepZnLd=NAN
** ~~~ ** Zone TempIndZnLd=NAN
** ~~~ ** Zone ThermostatSetPoint=0.00
** Fatal ** Program terminates due to above conditions.
...Summary of Errors that led to program termination:
..... Reference severe error count=1
..... Last severe error=DualSetPointWithDeadBand: Unanticipated combination of heating and cooling loads - report to EnergyPlus Development Team

Can you help me with that please? I don't really know what to do :-(

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