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Is it possible for Openstudios to suggest/autosize HVAC systems based on heating and cooling loads ?

asked 2015-04-29 16:28:26 -0600

RMAK's avatar

updated 2020-03-10 09:51:17 -0600

Hello Everyone, I am doing my Design Project now and am carrying out an Lifecycle Cost Analysis. I was reading this research paper by Joshua Kneifel who was able to "...autosize the HVAC system to determine the smallest system that will meet the ventilation load requirements." It should be mentioned that he used EnergyPlus 3.0 to do this. I was wondering if the same could be done with Openstudios. I thought that I would change the building insulation and windows to get different heating and cooling load and then use the Openstudio software to "suggest" or "autosize" an HVAC system for me. It should be noted I have no idea about HVAC systems. Thank you in advance.


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answered 2015-04-30 12:31:05 -0600

By default OpenStudio creates models that utilize the autosize feature built into EnergyPlus. If you make no effort to "hardsize" EnergyPlus will automatically compute minimum systems to meet load and ventilation requirements.

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Kyle is correct, and if you want to see these autosized equipment sizes, you can look in the Component Sizing section of the EnergyPlus Report, which you can pick from the dropdown on the OpenStudio results tab .

aparker's avatar aparker  ( 2015-04-30 12:41:23 -0600 )edit

I'd like to add a comment here about "autosizing" that seems to be mean different things in different programs. In EnergyPlus, "autosizing" means doing a Design Day calculation to derive the smallest HVAC capacities needed to adequately condition the space. In other programs like DOE-2 (eQUEST), "autosizing" means simulating the building loads for the entire run period or weather file to find the peak loads which are then used to derive the minimum needed HVAC capacities. The differences between the two approaches can be significant.

Joe Huang's avatar Joe Huang  ( 2015-04-30 13:11:48 -0600 )edit

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Asked: 2015-04-29 16:28:26 -0600

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Last updated: Apr 30 '15