luis melo's profile - activity

Hi everyone,

The figure below represents the simulation results from a simple model without HVAC system. (energy plus) How can I neutralize the generator end uses, in order to avoid your contribution to building consumption?

Thank you!

The problem is solved. I changed the numbers of timesteps from 6 to 12. Lower number of time steps leds to higher delta T between the timesteps (higher than Temperature Convergence Tolerance).

It was my first option, and doesn't work.

Thank you!!

I was trying to simulate in Eplus a double skin façade with four vertical thermal zones (subzones) when I got this Warning: "Inside surface heat balance did not converge with Max Temp Difference [C] =2.026E-003 vs Max Allowed Temp Diff [C] =2.000E-003"

What's the correlation with Heat balance algorithm? Can anyone help me?

Thank You

I found the solution in https://windows.lbl.gov/software/wind.... There is a tutorial named IGDB data file format.pdf with complete process description.

To take into account BSDF in fenestration (frame + glass) I'm using THERM and WINDOW (LBNL) because this tools are able to export IDF files. However I need to modeling spectral data of PV cells and I think OPTICS (LBNL) is not so friendly to do this. I spent hours with MDB file (ACCESS) creating a spectral data but it fails.

Can I use materialproperty:glazingspectraldata (ENERGYPLUS) for this purpose? Is there any way to export the spectral data from ENERGYPLUS to WINDOW/THERM?

How can I edit the date values in ELEMENTS to a timestep from 1 hour to 10 minutes?

Ok Rob, I'll check this parameters, for instance, the illumminance map is closer than 0,30 m from walls and probably it can affect the result. Thank you!

Thank you Rob!! I already ran your last alternative, and the results were more accurate than in energyplus. About 5 times lower because the splitflux method used in Eplus overestimated the illuminance values, I guess!!

Thank so much for help

Wich is the most suitable tool for monthly energy consumption assessment, in terms of daylighting benefits?

Hi Rob, Thank you very much for help. I followed your instructions and the simulation works. Now, I need to learn about energy consumption analisys, with Openstudio. Can you show me any tutorial?

Hi again, after run simulation I suposed that first alternative is impossible....Am I correct?[openstudio.radiance.ForwardTranslator] <0> Secondary DaylightingControl Daylighting Control 3 is not supported by Radiance, it will not be translated.

Hi Rob, I saw your tutorials, excellent for traineers, but I have doubts. Imagine a L shape small building and I want to analyse daylighting performance in two adjacent zones separated by air wall. Should I put the illuminance map crossing the air wall? Or is it mandatory 1 for each zone? Tks so much!

The large glazed area is a glassdoor who is a unchanged surface. The main goal of the study is to analyse the STPV performance in terms of save energy with daylighting.

I'm trying to send by in-mail, ok?

Hello Wassem, thank you for help, but, even taking into account all objects listed above, comparing the results between windows A and B with opaque surface and the same windows with semi transparent photovoltaics, the energy consumption in KWh remain with same values. It doesn't make sense because there is daylight reaching the space in second case. Do you know how can i fix it?

(input output reference): *Fraction Replaceable. This field defines the daylighting control for the LIGHTS object. If Daylighting:Controls or Daylighting:DELight:C

Hello Wassem, thank you for help, but, even taking into account all objects listed above, comparing the results between windows A and B with opaque surface and the same windows with semi transparent photovoltaics, the energy consumption in KWh remain with same values. It doesn't make sense because there is daylight reaching the space in second case. Do you know how can i fix it?

(input output reference): Fraction Replaceable. This field defines the daylighting control for the LIGHTS object. If Daylighting:Controls or Daylighting:DELight:Controls is specified for the zone, this field is used as an on/off flag for dimming controls. If set to 0.0, the lights are not dimmed by the daylighting controls. If set to 1.0, the lights are allowed to be dimmed by the daylighting controls.

How can I compare the Light Electric power usage per hour before and after using daylight sensors? I suposed that Light Electric Power object is able to do this. Am I correct? I want to report something like below image.

Source: (Garg, Vishal) Centre for IT in Building Science, IIIT, Hyderabad, India

Annie thank you!! The real grill was built whit cork insulation + timber, thus what do you think about "movable insulation object"? Sounds great for you?

Thank you soo much.

The questions above, refers to double skin façade, when i have multi zones, linked by air flow network. However, i'm not sure about the vents in terms of physical properties.

Hi Annie, How is possible to modelling physically the vents/grills? Assuming that my model has only two positions (tottaly close or open), i suppose that we can build opennings with "virtual glass" considering high thermal and transmittance coefficients. Am I correct? Thank you!!

Hi Neal, How about your project with ASHRAE? When do you expect that it i´ll be published?

There are several methods in EnergyPlus for calculation of the interior convective heat transfer coefficients. Which one considers the cavity airflow velocity for calculation in order to analyse the overall energy performance of a natural ventilated photovoltaic façade?

I need to analyse which is more applicable for whole building simulation take into account that bidirectional transfers were already calculated.

Exactly, and study how much is possible to reduce the energy consumption for artificial lighting and HVAC using appropriate semi transparent photovoltaic windows.

Thank you, I'll try to do this and let you know about results!! But I guess that its possible!

I cannot found specifications about semi transparent photovoltaics in inputoutput reference.