Hard-sizing equipment capacities in OpenStudio?

asked 2024-11-22 16:43:52 -0600

mattkoch's avatar

updated 2024-11-24 17:30:11 -0600

Another OpenStudio subject I am not entirely certain on is hard-sizing of equipment.

If I know what my air handler fan flow rates, pressure rises and efficiencies are and what my water coil water and air flow rates and inlet and outlet temperatures are, is it sufficient to enter these in FanVariableVolume and CoilCoolingWater and leave corresponding parameters in AirLoopHVAC on "autosize"?

Same for PumpVariableSpeed or BoilerHotWater - is it sufficient to specify flow rates, pressure rises, efficiencies and (boiler)capacities there and leave corresponding parameters in PlantLoop on "autosize"?

What about those AirTerminalSingleDuctReheat? Can I leave everything on "autosize" there and just specify the flow rates and temperatures in the CoilHeatingWater under it? What if my engineer tells me a VAV TU has x gpm of hot water, y cfm minimum air and z cfm maximum air - would I not have to enter that under AirTerminalSingleDuctReheat? What if he also says it has abc kBTU/h heating capacity, does that go in CoilHeatingWater?

Thanks.

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Comments

Matt, thanks for asking this question. Generally, if I start hard sizing, I try to take it as far as I can and eliminate all autosizing. I can't point to why, I just have been advised to do this, and think it works best.

Greg Estep's avatar Greg Estep  ( 2024-12-02 12:47:10 -0600 )edit