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How to Validate HVAC loop temperatures at each node in OS

asked 2015-12-01 11:58:32 -0500

SVVitale's avatar

I am troubleshooting my design boiler sizing and DX cooling coil sizing for my model built in OS. I am using a Packaged Rooftop VAV with Reheat in my model which is for a laboratory. Through input selections I am trying to make sure that economizer is not modelled since I want a 100% outdoor air system at all times. My 100% OA supply fan is intended to be balanced by my Zone Exhaust fans which are for fume hoods. I think I have the air systems set up correctly because my fans are all properly sized by E+ based on my inputs, but my coil loads (both DX and hot water) appear to all be undersized. I am suspecting that somehow the system might think it is still a recirculating system pulling back and mixing in some return air to "degrade" the inlet conditions away from extreme winter and extreme summer design day temperatures, hence undersizing my boiler and DX coil.

Is there a way to drill down into the E+ output file(s) to identify the air temperatures and air enthalpies at each node of my air system so that I can see if I still have some settings that are incorrect in OS?

I am not an E+ person (yet) so if there is a method I need a knowledgable person to spoon feed me the solution, if possible. Thanks!!

FYI, for more information about how I've set up my model, see this link for a question I posted earlier.

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answered 2015-12-01 12:06:55 -0500

This answer includes a link to a measure that you can add to you model to give node temperature, flow, etc. outputs. You can find the node names by selecting them from you system diagram, and entering that name as the measure argument. Just add more instances of that measure to get information for multiple nodes. Once you've run the simulation with all those output variables added, you can examine the outputs using ResultsViewer, as explained here.

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Thank you very much. This is very helpful. Hopefully it will help me figure out why my boiler and DX coil are undersized.

SVVitale's avatar SVVitale  ( 2015-12-01 13:29:01 -0500 )edit

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Asked: 2015-12-01 11:58:32 -0500

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Last updated: Dec 01 '15