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Thanks for this update. To be 100% clear, the question asks about the Commercial Reference Buildings (pre- and post-1980 typical constructions) and the text of replies mentions the Reference Buildings, but the linked Planned Features post on the OS website indicates DOE's Prototype Buildings (built to 4 different versions of ASHRAE 90.1). Are the plans to make available Prototype Building models only? Will they be for all versions of code? FWIW, this is one user for whom the reference building models are of greater interest...Thanks!!

Thanks, Michael. In short, then, it seems that the answer to my follow-up question to Archmage is "yes." At least in your example and in mine, a system that is not oversized by 20 percent according to the summer design day method will fall far short of meeting its load at conditions under which it is very likely to have to operate. Thanks to all for the helpful insights!!

Thanks @Archmage! For my definition of peak coincidence I am looking at the hours between 4 and 6 PM on hot summer days. While that is a period of extreme loading on cooling coils, i've confirmed that there's no interaction with a thermostat setpoint change in my model. More fundamentally, your answer suggests that the ASHRAE Fundamentals 0.4% design day sizing method significantly undersizes systems for the loads they are likely to encounter (e.g. by 20%) before application of a sizing factor. i do expect some loads to not be met, but I did not expect by that much!

Kyle, thank you for responding to my post. Your comments are correct - the nominal capacity and the cited COP are indeed at rated conditions, which makes my calculation crude at best. You are also correct that my issue is similar to the referenced post. Specifically, like the creator of that post, I only see sensible loads in the zone sizing and system sizing reports, which are lower than the nominal total capacity by about the same 20% as my sizing factor (1.2). However, as in the cited section from the I/O Reference Manual, I take that difference to be due to the inclusion of latent loads (and, yes, also incorporate the differences between design operating conditions and rated operating conditions).

I am going to work on a thing or two and revise my original post shortly - I still have a core issue, which is that - even using not exactly right capacities and COP values to estimate full load input electric demand on the cooling systems - I would expect the peak coincidence ratio to be much closer to 1/1.2 than to unity given that the sizing run applied a 120% sizing factor.

Hi,

I am working with DOE Commercial Reference Building models to do some simplified, high-level analysis of what might be expected to be 'typical' levels of the coincidence of the load on HVAC systems in commercial buildings and utility system (transmission grid) peak demand. For the case described here, I am running the post-1980 Full Service Restaurant model for the Houston weather zone as developed, using EnergyPlus 7.2 (latest version in which models are available on DOE website).

My issue is that the models appear to be telling me something impossible: that cooling electricity energy use in several hours (77 hours, when run using TMY3 data) exceeds the amount of electricity the HVAC systems should draw when fully loaded. To arrive at this conclusion I obtain hourly Cooling:Electricity from the Meter file, and I obtain the HVAC systems capacities as estimated from the sizing run from the Cooling Coils table in the Equipment Summary of the HTML Tabular output report.

According to the .mtd file, this is what is rolled up on the Cooling:Electricity meter:

For Meter=Cooling:Electricity [J], ResourceType=Electricity, EndUse=Cooling, contents are: PSZ-AC2:2COOLC DXCOIL:DX Cooling Coil Electric Consumption PSZ-AC1:1COOLC DXCOIL:DX Cooling Coil Electric Consumption PSZ-AC2:2COOLC DXCOIL:DX Cooling Coil Crankcase Heater Consumption

For capacity from the sizing run, I use the sum of the Nominal Total Capacity of the two units as reported in the Cooling Coils table of the Equipment Summary (Table report). To convert this (output) capacity to input demand, I divide by the COP.

My basic question is, how can this happen? Have I misunderstood/misused either the Nominal Total Capacity of the cooling coils from the Equipment Summary or the Cooling:Electricity meter 8,760 data as data sources for this comparison?

Further confusing matters, given use of a cooling sizing factor (Sizing:Parameters object) of 1.2, I would expect the maximum ratio of hourly cooling energy use (demand) to capacity to be closer to 1/1.2. Design day conditions used are standard - ASHRAE Fundamentals 0.4% design day, and I've run with both TMY2 and TMY3 data (FWIW, it's only with the TMY3 that I get demand in excess of capacity - with TMY2 I do get a coincidence factor less than 1, but not much less - 0.96).

Any insights would be greatly appreciated.

@aparker I agree this would be a highly valuable capability. Would this measure also build up the DOE Commercial Reference Buildings? Also, it sounds like the Measure is already in existence, since you are running regression tests against the IDF files. Any chance there could be a preview/non-guaranteed beta version of the measure made available? Thanks!!

following what I'm reading in this thread - if I want to translate the DOE Commercial Reference Building .idf files that are EnergyPlus 7.2 files to .osm, then I'd need to wind back to OpenStudio 1.0?

thx.

Apologies to those reading this, I've found another thread with info on importing from idfs. So I know a bit more than I did. Now I'll just figure out how to post questions as questions rather than answers...

Hi -

Was it previously feasible just to directly open the DOE Commercial Reference Buildings from the 'templates' that used to ship with OpenStudio? Juxtaposing page 3 of the OpenStudio Basic Workflow Guide with the fact that others seem to have those models (https://unmethours.com/question/1305/...), it seems maybe so. However, it also seems that with the move from templates to the wizard for starting new .osm files in sketchup, the ability to open the commercial reference building models (if it existed) no longer exists. Am I wrong?

Given I don't have an .osm file, I'm trying to load the DOE commercial reference buildings in OpenStudio by importing the idf's from the DOE website. I was able to import the most recent (V 1.4_7.2) Large Office models using the OpenStudio Sketchup Plugin (Sketchup 14.1) and from there export to OpenStudio (using version 1.5 - i got errors using 1.4). For the large office building, there were about 4300 lines of code from the idf that were not imported via the plugin, instead being sent to an "untitled-untranslated.idf" file. I should also mention here that I had no luck directly importing the idf into OpenStudio.

i'm new to OpenStudio, but what mostly appears to be missing in the model is the mechanical systems, which seems pretty consistent with what's in the "untitled'-untranslated.idf" file. I'm not the first person to do this , so I'm basically wondering:

If there are not already OpenStudio versions of these models publicly available, does anyone have suggestions or a checklist for what needs to be done to build out the reference buildings, starting from the .osm files that can be created from the .idf files downloadable from DOE?