[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [EnergyPlus_Support] Problem of Zero Design Cooling & heating Load

Typically this problem arises when design day schedules and thermostats are not used, and rarely is it the case that there are not actually any heating or cooling loads for a space.. (once in a while there can be no heating or cooling load, but not both) 

For trouble shooting and general best practice for HVAC design calculations in Energy Plus:   The first thing to do is to make sure you do not have dual setpoint thermostats for design days.  Then, check if your heating design day schedule for heating has all internal loads off (or a reasonably low fractional values) and no solar design model so that it represents a worst case cold condition. Then check if your cooling design day schedule has all internal loads on (or a reasonably high fractional values) and solar design model so that it represents a worst case hot condition.  This assumes you are using ASHRAE design day conditions. 

Below are some examples: 
Name Summer Design Day in Annarbor Winter Design Day in Annarbor
Month 7 1
Day of Month 15 15
Day Type SummerDesignDay WinterDesignDay
Maximum Dry-Bulb Temperature 29.5 -5
Daily Dry-Bulb Temperature Range 11.5 0
Dry-Bulb Temperature Range Modifier Type
Dry-Bulb Temperature Range Modifier Day Schedule Name
Humidity Condition Type WetBulb WetBulb
Wetbulb or DewPoint at Maximum Dry-Bulb 24.5 -5
Humidity Condition Day Schedule Name
Humidity Ratio at Maximum Dry-Bulb
Enthalpy at Maximum Dry-Bulb
Daily Wet-Bulb Temperature Range
Barometric Pressure 98287.2 98287.2
Wind Speed 0 3
Wind Direction 0 0
Rain Indicator No No
Snow Indicator No No
Daylight Saving Time Indicator No Yes
Solar Model Indicator ZhangHuang
Beam Solar Day Schedule Name
Diffuse Solar Day Schedule Name
ASHRAE Clear Sky Optical Depth for Beam Irradiance (taub)
ASHRAE Clear Sky Optical Depth for Diffuse Irradiance (taud)
Sky Clearness 0.98 0

Name Winter Design Setpoint Summer Design Setpoint
Schedule Type Limits Name Temperature Temperature
Field 1 Through: 12/31 Through: 12/31
Field 2 For: WinterDesignDay For: SummerDesignDay
Field 3 Until: 24:00 Until: 24:00
Field 4 21.111 24.444
Field 5 For: AllOtherDays For: AllOtherDays
Field 6 Until: 24:00 Until: 24:00
Field 7 21.111 24.444

Name TopFloorThermostat BottemFloorThermostat
Zone or ZoneList Name TopFloor:Zone5 MainFloor:Zone3
Control Type Schedule Name Zone Control Type Sched Zone Control Type Sched
Control 1 Object Type ThermostatSetpoint:DualSetpoint ThermostatSetpoint:DualSetpoint
Control 1 Name Dual Setpoint Dual Setpoint
Control 2 Object Type ThermostatSetpoint:SingleCooling ThermostatSetpoint:SingleCooling
Control 2 Name Cooling Design Setpoint Cooling Design Setpoint
Control 3 Object Type ThermostatSetpoint:SingleHeating ThermostatSetpoint:SingleHeating
Control 3 Name Heating Design Setpoint Heating Design Setpoint
Control 4 Object Type
Control 4 Name

Name Heating Design Setpoint
Setpoint Temperature Schedule Name Winter Design Setpoint

Name Cooling Design Setpoint
Setpoint Temperature Schedule Name Summer Design Setpoint

Jeremiah D. Crossett
  | Senior Analyst  |  Phase Change Energy Solutions
120 E. Pritchard St.  | Asheboro, NC 27203 
 | Mobile 503-688-8951

On Thu, Dec 5, 2013 at 6:13 AM, sheelam khare <sheelam_khare_26@xxxxxxxxxxx> wrote:

Hello All,
I am using the Energy Plus software to simulate the energy performance of the Civic Center Building located in Barcelona, Spain. 
In the results, the design Cooling  & Heating load  for two zones are coming as Zero. I have tried to resolve this in many ways but unable to solve this.
Please give your valuable suggestions to solve this problem.

Thanks with regards....
Sheelam Khare


Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx

The primary EnergyPlus web site is found at:

The group web site is:

Attachments are currently allowed but be mindful that not everyone has a high speed connection.  Limit attachments to small files.

EnergyPlus Documentation is searchable.  Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.

Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe