IronBug Gas DHW System Details?

Hi everyone,

I am wondering if anyone might know the answer to a couple questions that have come up modeling a gas DHW (residential) system in IronBug? Mostly it seem to be working great, but I wonder about a couple details:

  1. When I autosize the WaterHeater:Mixed Volume and Heat Capacity, I get a warning that I should also be including a WaterHeater:Sizing object.


    In the Big Ladder docs they say that I should just need to add that Sizing object, which seems fine - but I wonder if there is already a built-in way to do that through IronBug? I couldn’t find one, but I wonder if I missed it? It seems that I can always add that as an additional hard-coded element, but just thought I’d ask first?

  2. I was able to find some nice DHW schedule and load inside the DOE’s Prototype buildings. I’ve added that as a FlowRateFractionSchedule to the zone demand side:


    which works well. The only thing I don’t love is that I seem to get duplicate schedules when I do it this way?

    I wonder if there is alternate way I should be setting up the Demand Loop so that I don’t have these duplicates? On another project I’m working on with >500 units that ends up being a lot of duplicate schedules…

  3. Last, I am wondering if there is a way to break out the DHW water heating end-use energy? I have tried applying end-use designators:


    and that sort of works to get the water part, but I’d love to be able to dis-aggregate the heating energy as well if possible? Right now I get:

    but I wonder if anyone knows how to split out the heating energy as well as the water volume?

if anyone might have suggestions on any of that, I’d very much appreciate it! example file attached for reference.

thanks!
@edpmay

Example_Gas_DHW.gh (72.1 KB)

Hi @edpmay,

Sorry for belated reply.

  1. WaterHeater:Sizing object is just added to OpenStudio last week, but it has not been merged and released. We will have to wait.

  2. Duplicated schedules: this shouldn’t happen, it should reuse the existing schedule. I will investigate this issue.

  3. You can use OutputParams to get WaterHeater heating energy:

awesome! Thanks @MingboPeng - that outputParams was not on my radar. I’ll take a closer look and try and fold that into my models going forward. Really appreciate it!

best,
-Ed