Michael Pelton's profile - activity

Are the utility rate objects in OpenStudio ready to use yet? I would like to write an OpenStudio measure to incorporate tariffs (without using an EnergyPlus measure)... The online documentation seems to show that the objects are available - but are they fully functional?

It seems like there are 2 different ways to "set up" the object in the OSM file using a measure...

1. groundtemps = OpenStudio::Model::SiteGroundTemperatureBuildingSurface.new(model)

2. groundtemps = model.getSiteGroundTemperatureBuildingSurface

The first way assumes that the OSM file doesn't have this object in it yet, so it creates one. Pretty straightforward (but I'm not sure what happens if the object is already there).

I'm not sure how the second one works, because it looks like it is trying to "get" something that doesn't exist yet?

Is one of these ways better than than the other?

I would like to add ground temperatures in my model using an OpenStudio measure (as opposed to an EnergyPlus measure). Does anyone have sample code for this?

It looks like this might have something to do with differences in air density. The infiltration design flow rates are entered in volumetric flow units (m3/s) - but the hourly reports are showing fluctuations in mass flow units... When the OA temperature is low (i.e. the air is dense) the mass flow rates seem to be higher (and vice versa)...

However, the OpenStudio report lists an Average ACH and a Minimum ACH (both volumetric) and they are very different (by an order of magnitude for most zones)... Still can't explain this.

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've recently updated an OS 1.8.0 model to 1.9.0. The model ran fine in 1.8.0.

When I run the model in 1.9.0, it says it fails. The OpenStudio results are not shown. However, the EnergyPlus results are shown and the eplusout.sql data seems to be intact... It appears as though something failed after the EnergyPlus run completed - but I can't find what went wrong. Any ideas?