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What is SizingPeriod:DesignDay

asked 2015-11-21 06:52:08 -0600

tech91's avatar

updated 2017-05-29 17:49:38 -0600

Hello, I have downloaded the Weather Data of Amsterdam: http://goo.gl/35dKl7 This zip includes NLD_Amsterdam.062400_IWEC.ddy. Inside this file there is an item SizingPeriod: DesignDay, it includes eight items reported 4 to 21 January and 4 referred to 21 July.

The item SizingPeriod: DesignDay what is it? Should I put these items in my 8 .idf file (which is my project)? When you click in EP-Launch Variables and then I get the excel file with the annual outdoor temperatures (why I have called it) but how can I modulate temperatures SizingPeriod: DesignDay with those who gave me the file automatically .epw (Amsterdam)?

Thanks for the support

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answered 2015-11-21 07:41:31 -0600

The ddy file contains information for the building Site:Location. The SizingPeriod:DesignDay object(s) is used when a sizing simulation is performed to automatically size equipment. The SimulationControl object specifies which parts of a sizing run will be executed. A zone sizing simulation is typically performed for any sizing simulation. A system (air loop) sizing simulation is performed when AirloopHVAC objects are included and a plant sizing simulation is performed when chllled or hot water loop are included.

SimulationControl,
  Yes,                     !- Do Zone Sizing Calculation
  Yes,                     !- Do System Sizing Calculation
  No,                      !- Do Plant Sizing Calculation
  Yes,                     !- Run Simulation for Sizing Periods
  Yes;                     !- Run Simulation for Weather File Run Periods

When Run Simulation for Sizing Periods is set to Yes, several methods can be used to perform a sizing simulation. The most common is to use one or more SizingPeriod:DesignDay to define the most extreme weather conditions for the geographic location selected for study. Typically two or more sizing periods are selected to define the heating and cooling extreme weather conditions. The examples below show a sizing period where the conditions (temperature and moisture) specified in the SizingPeriod:DesignDay object represent 99.6% or 99% of the weather conditions for the heating season and similarly for the cooling season (i.e., an AC system would be capable of meeting the loads 99.6% or 99% of the time). You would typically select one of these for heating and one for cooling.

SizingPeriod:DesignDay,
  San Francisco Intl Ap Ann Htg 99.6% Condns DB,     !- Name

SizingPeriod:DesignDay,
  San Francisco Intl Ap Ann Htg 99% Condns DB,     !- Name

SizingPeriod:DesignDay,
  San Francisco Intl Ap Ann Clg .4% Condns DB=>MWB,     !- Name

SizingPeriod:DesignDay,
  San Francisco Intl Ap Ann Clg 1% Condns DB=>MWB,     !- Name

The systems specified to condition the building must be sized sufficiently to meet the building load (i.e., be able to meet the thermostat set points given the expected weather conditions). These systems, and other components (coils, fans, pumps, etc.) can either be manually sized by entering a value, or can be automatically sized by entering "autosize" in the field for air flow rate, capacity, water flow rate, etc.

AirTerminal:SingleDuct:VAV:Reheat,
 SPACE1-1 VAV Reheat,     !- Name
 ReheatCoilAvailSched,    !- Availability Schedule Name
 SPACE1-1 Zone Coil Air In Node,  !- Damper Air Outlet Node Name
 SPACE1-1 ATU In Node,    !- Air Inlet Node Name
 autosize,                !- Maximum Air Flow Rate {m3/s}

Coil:Heating:Gas,
 SPACE1-1 Zone Coil,      !- Name
 ReheatCoilAvailSched,    !- Availability Schedule Name
 0.8,                     !- Gas Burner Efficiency
 autosize,                !- Nominal Capacity {W}

Fan:VariableVolume,
 Supply Fan 1,            !- Name
 FanAvailSched,           !- Availability Schedule Name
 0.7,                     !- Fan Total Efficiency
 600.0,                   !- Pressure Rise {Pa}
 autosize,                !- Maximum Flow Rate {m3/s}

AirLoopHVAC,
 VAV Sys 1,               !- Name
 ,                        !- Controller List Name
 VAV Sys 1 Avail List,    !- Availability Manager List Name
 autosize,                !- Design Supply Air Flow Rate {m3/s}

When autosizing equipment, in addition to using the SizingPeriod:DesignDay object(s), you will need to include sizing objects for each zone and each air loop (if included in the ... (more)

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Asked: 2015-11-21 06:52:08 -0600

Seen: 1,690 times

Last updated: Nov 21 '15