RE: [EnergyPlus_Support] Re: LowTemperatureRadiant:VariableFlow No HVAC Energy Use

[YuanLu Li <yli006@xxxxxxxxxxx>]

I am a little confused reading you posts.  When running an example file, there is no need to add any input data.   The following is how I use the example file.

 This is a general answer on how I use the example file and how I study it and modify it to solve my problem.
In order to same time and energy, I usualy lokk at the simulationCcontrol and set it to run the Designday sizing only.
     ....      Yes, !- Run Simulation for Sizing Periods      No; !- Run Simulation for Weather File Run Periods

Then make sure        SizingPeriod:DesignDay, objects.
are there, so that I can run the designday sizing simulation only without the weather file. 
The informationin the  location and the data in the DesignDay objects are sufficient to run a simulaton with useful results.
.
Make sure also  that the .rdd file is requested in IDF format.  If the building information is not in the IDF.  ask for the DXF as well.

The purpose of this first run  is to get the  rdd file and to see that the example file is complete.  


You can then study the output cata, and the building geometry.

If the .csv file does not show what you wanted to see, then you use the IDFeditor to add the variable.
All the monthly and annual averaged value should be ignored.

The variables that must be displaied in the first simulation should be Outdoor Dry Bulb, and Zone Mean Air Temperature values in timestep intervals.  Schedule values should also be displayed.

The heating and cooling should be in rate values (watts) rather than energy values.


If there is an SVG diagram, then a sckematic diagram can be drawn to show the temperature values and verify that you do agree with the schedule values.

When you using some special equipment, you can then use the IDFeditor to see what are options and meaning, and default values for that object.

After you have studied the ecample results, then you can decide what need to be changed.

In order to change, you must know how a real system works.  How the EPlus simulate the real components.


You cannot change the values in the input file in any way you wish.

For example, you mentioned that the water in the tube must be 35°C. Why?

Whether you are an architect, engineer, research student, you  must know why you are chooding the low radiant panel for simulation.  Its advantage and disadvantage, and problems to watch.

For cooling, low readiant panel has condensation problem.  For moth heating and cooling, its action is by convection and is slow aeting.  Therefore, itis not very suitable as the primary HVAC component.

How to control it?  The zone thermostat when used for the provary system control, it would not be avalable for the panel control.  Therefore the panel temperature is controlled by the difference to the zone set point or OD temperature.  The water wll be on.off controlled.  The temperature of the inlet and outlet temperature is not normally variedby programming input.  The inlet water bemperature is determined by the plant loop set point.