carlobianchi89's profile - activity

Thanks, this is great! I tried to implement your strategy and I noticed that actually the issue is exactly and just in

I am modifying in EnergyPlus a simplified 1-zone model, changing the control type of the UnitarySystem.

I am attaching 2 pictures for 1 day in July.

The starting model has a control type (second field of the unitary system) set to "Load". The zone temperature is always maintained within the setpoints, the heating coil and the cooling coil work fine (first picture).

When I change the control type to "SetPoint", the zone temperature is not controlled anymore, it gets quite high, and the cooling coil does not even turn on. I added a SetpointManager:SingleZone:Cooling and a SetpointManager:SingleZone:Heating, but nothing happens. I switched to SetpointManager:MixedAir, but same story.

Here is the complete model: https://drive.google.com/file/d/1clKe...

What knobs should I play with to make the model work, when I change from Load to SetPoint?

Thanks, this is great! I tried to implement your strategy and I noticed that actually the issue is exactly and just in

EnergyPlus AirLoopHVAC:UnitarySystem: "SetPoint" vs "Load" control type I am modifying in EnergyPlus a simplified 1-zone

I would like to add to this a (hopefully) useful tool I created during my PhD research period: https://energysystems.mec

eQuest Refrigeration - hourly reports I am modeling a refrigeration system with eQuest Refrigeration 3.65. I would like

The file I uploaded is actually not the one I used. Something happened during the copy$paste process. The uploaded file

I think I found the problem. For some reasons there are some differences between controlling the incoming Diffuse and D

Thanks for clarifying that, I was mistaken. I tried your option. I changed the longitude from -111-ish to -103.5-ish. T

Oh, and I am sorry you've never heard about the actuators. They are quite useful features, especially if you want to cus

Dear Joe, The EnergyPlus_Support group was very little responsive in the past with some questions I posted, so I do thi

Dear Joe, The EnergyPlus_Support group was very little responsive in the past with some questions I posted, so I do thi

I am about to test your option, even though I am a little skeptical about. Right now, including the updates I talked abo

Dear Joe, The EnergyPlus_Support group was very little responsive in the past with some questions I posted, so I do thi

Wait, I got the same results you got, but are they reasonable? How can I have a peak of 2597 W/m2 at 40º Latitude and wi

I was running my simulations on Windows on a virtual machine on my Mac. For some mysterious reasons, re-running the simu

That's weird. Did you use exactly ALL the data I used? I mean, did you use the same: - IDF File - SAMPLE.epw - Radiation

If my building is perfectly cubic, perfectly aligned with the cardinal directions, if direct and diffuse components are

I did some tests and I am not sure I follow you. I plotted direct and diffuse radiations and they are perfectly symmetr

I am having hard times with the way EP treats incoming solar radiation. I created a simple test case: a cubic building, perfectly aligned on the north direction, only red-brick, no surrounding objects, ideal loads, constant internal room temperature, constant air temperature, constant wind speed, constant humidity. The only thing that varies is the incoming solar radiation. I used a model to determine the clear-sky radiation in my location, the TMY3 may contain some weird effects due to the clouds' presence. I set EP to output "Surface Outside Face Incident Solar Radiation Rate per Area [W/m2]" on each surface. I checked out January 1 (the first 24h of the year) and something weird happens.

All the surfaces except west and east show a symmetrical collection of radiation during the day, as expected. You can see that in the picture attached: C:\fakepath\SolRad.jpg

East and West are not supposed to be symmetric, they receive direct radiation in different parts of the day. However, the peak of incoming radiation for the west side is much higher than the peak for the east side.

How is it possible? What possibly can alter the collection of solar radiation on those 2 surfaces?

Note the material of each surface is the same. Attached you can find the plot for January 1, I can provide the .idf and the .epw file if you want to replicate the analysis.

Actually I think I got what you mean! I am gonna make some more tests, but I think you're right! Thanks!

That's very interesting... My weather file is located in Salt Lake City, Utah. You can find all the data I used for my s

Issue with Solar Radiation collection I am having hard times with the way EP treats incoming solar radiation. I created

I am employing a CFD software to study site-specific weather boundary conditions. It takes into account incoming solar radiation as well as convection heat exchanges, providing surface temperatures through a global energy balance. I can, therefore, use EnergyPlus actuators on each wall to override the surface temperature.

The surface temperature provided by the CFD software already takes into account the radiative heat exchange with the sun, so I can't include it twice. I have to exclude the solar heat gain impact on my building model, modifying the building material properties. I can't just set the incoming radiation to 0 otherwise I would deny the "light gains" and the "heat gains" that come with the light filtered through the window glass.

I am setting the Solar Absorptance on the walls equal to 0 and I get the result I want. However, how can I set the same for a window? Basically, what I am trying to do is to exclude the radiant heat gain from the surface heat balances. I would like to exclude the solar heat gain on windows surfaces, without excluding the light solar contribution. Is there any way to do that, besides the Solar Absorptance coefficient?

I am using the EMS in EnergyPlus and customizing surface variables such as Dry Bulb Temperature, Wet Bulb Temperature and Wind Speed. I am imposing a Surface Dry Bulb Temperature that takes into account the convective and radiative heat exchanges between the external surface and the environment. If I run the simulation with EnergyPlus, though, the heat gain from the sun is taken into account as well, using the radiation data in the EPW file. How can I turn it off? I can easily regulate the convective heat exchange, customizing the convection coefficient on each surface, but what can I do with the radiative heat exchange? If I set to 0 the incoming radiation I eliminate this contribution, but I also eliminate the sun contribution in terms of light and that's not ideal.

Yes, sorry, I modified the question and I added more details. What I am talking about is basically the effect of visibl

How can I set Solar Absorptance for windows? I am employing a CFD software to study site-specific weather boundary condi

I am trying to exclude the solar heat gain on the whole zone. On walls, setting solar absorptance to 0 works fine enough

How can I set Solar Absorptance for windows? I am trying to exclude the solar heat gain impact on my building model, mod

I can open a new one, hoping someone answers. However my question is relevant. I can have windows on a roof. Do you have

How is it possible to set the Solar Absorptance for windows? I can't find this coefficient to be set for windows. I woul

I am trying to study the site-specific weather effects on building energy consumption and I am using the EMS to customize dry bulb temperature, wet bulb temperature and wind speed. I am calculating wall-specific quantities with CFD. However, I need to be able to control the shades on each wall. Surrounding buildings create shades on each wall differently.

How can I do that? The shading control module in EnergyPlus only works for windows, not for whole facades. And there is no actuator to control direct and diffuse radiation on each wall.

Thanks for your help.

Following up on this answer, how can I set up solar absorptance for windows? It works exactly for what I am doing if I s

How can I turn off solar heat gains? I am using the EMS in EnergyPlus and customizing surface variables such as Dry Bulb