kramerica's profile - activity

@matthewSteen and @MarkAdams, is there an update to this? I also would like to edit the IDD without recompiling EnergyPl

I believe Design Builder Result Viewer used to combine the design days into the annual results. You could try to view th

Trace used to have a decent database of Trane and York chiller curves.

How to Model Fan Powered Boxes with VFDs? Is there a way to model a fan powered box with a Fan:VariableVolume in EnergyP

I would check the in.idf generated from OS and make sure the inputs are translating correctly. I found in a test that OS

Is it possible to use OpenStudio to do 62.1 multizone calcs for LEED EQp1 and EQc2? I would like to use OpenStudio to calculate the required outdoor air intake for multizone systems rather than the 62MZCalc spreadsheet. To do this would require a critical zone for each multizone system based on zone area and population.

Check your air handler fan objects types and if Fan:VariableVolume its max and min values, terminal units, sizing:system

Could you provide more information on your system such as air handler objects and terminal unit types, and any schedules

LEED baseline models should have the same HVAC and occupancy schedules as the proposed model. You only need to report th

You could also manually make a schedule using SetpointManager:Scheduled to have a SAT for winter and another SAT for sum

@davidgoldwasser, could you please confirm if this is an issue

has this been fixed in OpenStudio 2.2?

In OpenStudio 1.8.5 I cannot use the measure "Set Output Table to IP Units" without the program failing on runs. I believe this is because OS 1.8.5 (and possibly 1.9) have the measure "OpenStudio Results" built in which requires the output file to be in SI units. Even though the program fails on runs, it does create the EnergyPlus output report in IP units correctly. Is there a way in OS 1.8.5 to turn off the built in OpenStudio results?

I have a model with 4 VRF terminal units on the same system that serve an entire floor. I zoned the floor by space usage since there are bathrooms, corridors, electrical/utility rooms, stairs, and a lobby. I do not wish to combine the zones. Is there a way to model 11 zones on 4 VRF terminals in OpenStudio 1.8?

Would it be possible to add the object chiller:electric:reformulatedEIR and the bicubic EIRfPLR curve into the osm file?

I have tried the first approach I mentioned above and entered only the objects chiller:electric:reformulatedEIR, as well as curves needed for the objects. The model ran without error but did not show any difference than without the idf injected, meaning the objects were not put in the model, possibly due to node, or branch problems.

I am trying to model in OpenStudio a chiller:electric:reformulatedEIR as per the threads below using the EnergyPlus measure in OpenStudio Inject IDF Objects. What is a good workflow for using this measure in general?

Is it best to start with a blank IDF and just enter the objects to be entered into the OS model? Or, should nodes, branches, equipment lists, etc also be added to the IDF? Or, would it work to take an out.idf generated by the OS model and add the objects to a complete IDF model? I tried the 3rd method and am having a lot of errors for duplicate objects when I run it in OpenStudio, as well as node confusion.

Also, what is the end result of this measure? Does it import idf objects into OS so I can keep working in OS, or does it mean I have to edit the model in EnergyPlus?

https://unmethours.com/question/20973... https://unmethours.com/question/21043...

Is it possible to add the object Chiller:Electric:ReformulatedEIR in OpenStudio 1.13? I do not see it in the API, but is there any way to model this type of chiller in OS? The closest object to it is Chiller:ElectricEIR, but the two main differences between these two is that I need to model the "Reference leaving condenser water temperature" rather than the "reference entering condenser fluid temperature", and the "Electric input cooling output ratio function of part load ratio curve" is bicubic for leaving condenser water temperature rather than quadratic.

Is there a way to use night cycling for VRF systems in OpenStudio 1.11? If I click the "control" tab for the VRF systems, a message says that "control options are currently only available for air systems." I tried putting a schedule for the VRF fans to be on during occupied hours and off during unoccupied hours, but I would like to model these fans similar to with an air loop where they can cycle on and off during unoccupied hours. ASHRAE 90.1-2007 section G3.1.2.4 requires both baseline and proposed HVAC fans providing ventilation air must be modeled as operating continuously during occupied hours and cycled to meet cooling and heating loads during unoccupied hours.

@Julien Marrec, what file would you like me to upload and what is the preferred method to upload it?

OK, I have got it to work and can verify that it was an issue with my model and not the measure. The changes that @Julien Marrec suggest above do work in OpenStudio 1.12. The reason the measure did not work in my model appeared to be with underscores in zone names. When I changed this it worked.

@Julien Marrec & @aparker, I tried changing the code like you suggested but it did not work in OS 1.12. The model runs without the measure but fails while applying the measure.

You can also try running the OSM diagnostic script reporting measure from within the Sketchup plugin. This should remove orphaned subsurfaces, as well as other problems in geometry.

That's it. Thanks @Eric Ringold

Try looking at these threads below. It looks like your tdb is really low so it may be an error with an envelope input somewhere, such as in walkin coolers.

https://unmethours.com/question/9400/...

https://unmethours.com/question/12143...

I have an OpenStudio 1.12 model with ideal air loads on for all the 50+ zones and would like a quick way to turn them all off. I can't roll back to an earlier saved version of the model because I have made other changes that I would lose. Within the OS application it would take a long time to uncheck every ideal air loads box, and it would take about as long in a text editor. Would it be possible to alter the existing OS measure "Enable ideal air loads for all zones" so that it would turn off ideal air loads for all zones? Or would it be better to write a new measure to search for zones with ideal air loads on and change them to off?

Transfer air is mechanical system airflow introduced into one zone and then returned or exhausted from another zone. Is there a good way to model this in EnergyPlus?

How do you model the external adjacency for a ground-contact slab? This site recommends using ground temperatures of 2C below average internal temperatures (for large commercial buildings) and to not include ground material. Is this the recommended approach, and is it a constant temperature profile? What about for small or mid-size commercial buildings?

As a person new to the field I want to know the importance of energy modeling. Particularly the importance of it in future.

I would like to apply f-factor ground floor constructions along the ground floor perimeter zones of a model. Could someone tell me if I need to make an f-factor construction for each perimeter zone, or can I apply the same construction to all the perimeter zones? If I need to make a unique f-factor construction for each perimeter zone, do I input only that zone's area and exposed perimeter in the construction or for the whole floor? I have about 30+ zones on the ground floor and have tried multiple ways to see what works and have not had any luck.

Here's a detailed description of how I have been assigning f-factors:

1) In OpenStudio, create enough F-factor Ground Floor Constructions to assign the perimeter floor surfaces to. The best way to do this is create the first one and edit the f-factor field to what all the other ones should be, and put in a place holder for area and perimeter such as 1.0 to make it clear which ones have been edited later. Save and open the Sketchup plugin of the model.

2) Assign all the ground floor perimeter surfaces to the constructions created and change to boundary condition to GroundFCFactorMethod. I like going clockwise around the building so the numbering is easy to come back to later. Save and open the file in OpenStudio while keeping Sketchup open to do takeoffs in.

3) In Sketchup go through the surfaces with f-factors and open the group to click on the surface and get the area in Entity Info. Enter the area into OpenStudio for that construction. Do the same thing for the exposed perimeter of the surface. I do this by control clicking the perimeter lines and typing in the value from entity info into OpenStudio.

4) Repeat for all the F-factor constructions until all of them have been assigned to ground floor perimeter surfaces, have an f-factor value, a unique area, and a unique exposed perimeter.

5) Check that everything looks correct in the space tab under surfaces.

I have setup OS:SpaceInfiltration:DesignFlowRate in a model as follows:

Schedule = Fractional (Value=1 for all times) Design Flow Rate Calculation Method = Flow/ExteriorWallArea Flow per Exterior Surface Area = 0.0025 Constant Term Coefficient = 1 Other 3 Coefficients = 0

My understanding (after reading the Input/Output Reference) is that this should result in a constant flow of infiltration air (for all times) at the volume flow rate specified. However, when I review results, the infiltration rates in the model appear to vary significantly. Any ideas about what is going on?

I modelled the first floor, with the windows. Then I copy-paste the entire floor to generate the other floors; now every floor has the windows. Then I close and re-open sketch-up, and I open the openstudio model in skethup. I can see the external walls of the whole building, I can see the windows of the first floor, but can't see the windows of the other floors. Why do they disappear if I close and re-open sketchup?