Pouya's profile - activity

Thanks for the hint Lyle, I intend to evaluate the influence of internal objects near the windows and how they can contribute to thermal performance of the building.

Thanks a lot David! but there should be a difference if the material is next to the window or the other side of room where it doesn't receive much sunlight, no?

Dear All!

I intend to define an internal object (solid material) inside the building to evaluate the impact of thermal inertia for different materials, but Sketchup and EnergyPlus only allow me to define specific types of surfaces (roof, floor, wall) or subsurfaces (windows, doors, etc.). Would you please help me with that? Thanks a lot!

Thanks a lot! :)

Thanks! That's right, but what do you mean by unsupported? Is it still possible to create the geometry in SketchUp and export as an IDF file to EnergyPlus?

Dear Friends,

I used to use SketchUp for make the geometry of the building, but do the rest with EnergyPlus. Is it possible to do the geometry with EnergyPlus as well not needing any cross-platform tools like SketchUp, OpenStudio, etc.?

Thanks a lot in advance!

Thanks a lot! yes apparently EnergyPlus just considers the wind effect by default.

Hi!

The formula EnergyPlus uses for stack effect in ventilation is as follows: Qs=Cd * Opening Area * Schedule * SQRT(2gDH*(|(Tzone-Todb)|/Tzone))

The DH (referred as as "ΔHNPL" in the Inputoutput reference ) is defined as the height difference between the midpoint of an opening and the neutral pressure level. But EnergyPlus has considered the value of zero as default.

Doesn't this value of zero, makes the whole formula zero and consequently Qs=0?

Thanks a lot in advance!

With thanks to Julien, I found an interesting research on the same topic, for those who may be interested: http://www.zerocarbonhub.org/sites/de...

Dear Julien, thanks a lot for your detailed answer! it was one of the things came to my mind, and now I understand! really interesting indeed! The increase is quite reasonable, I will simulate more models with altering the windows U-value and solar heat gain coefficient to confirm the explanation. If you have your papers published would be great to read them! Once again, thanks a lot!

Dear All,

I have simulated two types of construction for a one-story house (1 living room, 1 sleeping room and 1 bathroom) in EnergyPlus. Each room has 1 window and the windows and doors are identical for both constructions. The house is quite small (320 square foot), there is no shading for windows and the location is in the climate zone 3B-dry.

The construction with lower u-value has lower required heating energy that totally makes sense. But this construction has higher required cooling energy than the other one. How can this be justified?

With and without considering natural ventilation and internal gains (home appliances) the results are same. The construction with lower u-value, has lower required heating energy, but higher required cooling energy.

I have rechecked the simulation various times and there seems to be no problem. Are these results justifiable? I appreciate any hint!

Thanks a lot in advance!

I was wondering how it's possible to define minimum indoor temperature as an input for natural ventilation while using Air Flow Network in EnergyPlus?

In EnergyPlus, by defining "AirflowNetwork:MultiZone:Zone" or "AirflowNetwork:MultiZone:Surface" it is possible to define "Indoor and Outdoor Temperature Difference Lower Limit" and "Indoor and Outdoor Temperature Difference Upper Limit", but there is no field to define minimum indoor or maximum outdoor temperature.

Thanks a lot in advance for your help!

I have built my model in OpenStudio and tried to model different shading scenarios in OpenStudio and afterwards in EnergyPlus but couldn't.

I used WindowProperty:ShadingControl in EnergyPlus and the only type of shading which worked was SwitchableGlazing but When I try with other types such as Interior or Exterior shade or blind it fails.

I have already defined Shading and blind material and added it to construction of the window, but faces the error:

GetHTSubSurfaceData: Window "SUB SURFACE 2" must not directly reference a Construction (i.e, "WINDOWS USED") with a shading device.

In FenestrationSurface:Detailed I have tried both referring and not referring to the defined shading control, but always face the above error.

Would you please help me with that?

I have used a thermostat (Dual Setpoint,18ºC and 25 ºC) for my model considering a HVAC template (Ideal Load Air System). The calculated annual heating and cooling energies is through considering a Variable-air-volume (VAV) terminal unit in Energyplus. I checked the heating and cooling energies through end-uses district cooling and district heating in results, please correct me if I am wrong. Moreover, How can I see (and change) the coefficient of performance (COP) of this VAV?

Thanks a lot in advance!

Thanks a lot! in fact I checked myself and was almost sure it's correct, but an expert asked me about that and I wanted to make sure, i double checked with the way you proposed! thanks again!

Dear All,

I've simulated a building in EnergyPlus for the weather of Nairobi (Kenya) which is located in the southern hemisphere. Would you please tell me if north and south swap for the purposes of heating and cooling loads in EnergyPlus? Do the results for heating and cooling energies represent them correctly or I must switch them afterwards?

Thanks a lot in advance!