ASHRAE Appendix G Baseline Systems - Constant Volume Systems?

grasshopper honeybee
1

Hi,

I am trying to map System 12 and System 13 from ASHRAE 90.1-2019 Appendix G to systems in Honeybee and am having a hard time finding an equivalent system. Am I overlooking one of the options or does a constant volume single zone system not exist in the Honeybee templates?

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2

@ELeriche I don’t know if those two are in the current templates but you can certainly make them in ironbug.
best
-trevor

3

@TrevorFedyna is correct that Ironbug is the best way to model these systems correctly right now.

Granted, if this constant volume system is for a space with really high, constant ventilation loads (eg. a clean room or a lab), using a VAV template is essentially going to perform the same way as a constant volume system (since the ventilation load is a lot higher than the space’s heating/cooling needs).

But CV systems are really simple (and generally very inefficient). They are basically just DOAS air loops sized on the room’s sensible heating/cooling loads instead of the ventilation loads. I’ll try to add template HVACs for these systems at some point and I opened an issue on the GitHub for it:

4

Thanks Chris and Trevor for your responses. Good to confirm that I wasn’t missing anything. As you suggested I’ll use Ironbug in the meantime and keep an eye on updates for when the system are included in the templates. Thanks!