Re: [EnergyPlus_Support] Calculation of Yearly Ideal Loads withoutHumidity Control

2011/1/13 Maciej Cichy <mcarchbud@xxxxx>

Thank you Jason,

It is helping me to get closer to the solution.

I have another question, when calculating cooling load without humidity control, does only sensible cooling is considered? It may be a basic question for a mechanical engineer but my background is in architecture. This is for study of relation between different buildings shapes and energy use and I do not want to consider humidity control.

Regards,

Maciej

Dnia 12-01-2011 o godz. 17:55 Jason Kirkpatrick napisa³(a):

Maciej,

Looking at the I/O Reference, pg 1085,

"Cautionary Note: The Ideal Loads Air System component does not control zone humidity levels. The Ideal Loads Air System component total cooling load is simply the enthalpy change between the mixed air condition (return air plus outdoor air, if specified) and the user-specified supply air condition for the current load. The latent load is the total load less the sensible load and may be positive or negative. "

If you include the following in your file:

Output:VariableDictionary, IDF;

and then run, you will get a file with extension .rdd that will contain a variable definitions for "Ideal Loads Air Sensible Cooling Energy" and "Ideal Loads Air Sensible Cooling Rate"

Output:Variable,*,Ideal Loads Air Heating Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Ideal Loads Air Heating Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Ideal Loads Air Sensible Cooling Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Ideal Loads Air Sensible Cooling Rate,hourly; !- HVAC Average [W]
Output:Variable,*,Ideal Loads Air Total Cooling Energy,hourly; !- HVAC Sum [J]
Output:Variable,*,Ideal Loads Air Total Cooling Rate,hourly; !- HVAC Average [W]

Now you can copy any of these Output:Variable definitions and place in your file and run again. The file ending in .csv will contain the results for these requested variables.

If you have also downloaded and installed the .eso reader, you can get see this variables output graphically.

Hope this helps.

Jason

On Wed, Jan 12, 2011 at 4:07 AM, macias@xxxxxxxxxx <mcarchbud@xxxxx> wrote:

Hi,
I would like to calculate yearly, ideal cooling and heating loads, without humidity control. I have planned to use IdealLoads object to do this. However this object requires specifying air humidity level for supplied air. The energy required for bringing the humidity to the specified level is added to the calculated loads.

Can anyone advise, if there is any simple option to simulate the ideal loads without humidity control?

And if not, if energy required by the ideal loads system without humidity control can be calculated by subtracting latent loads from the results received using the standard IdealLoads object?

Thanks and Regards
Maciej