Splitting Zones

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All,

I'm needing to split one thermal zone into 2 thermal zones. Originally the whole space was to be conditioned by one rooftop unit, and now we have 2 units serving the space. Is it possible to split a space in half?

Thanks!

Stephanie Andersen

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Stephanie,

If the RTUs are identical, or at least of similar efficiency, my preference would be to combine their capacities, airflows etc. and model them as one unit/system. It is possible, but time-consuming to add zones once you have made changes in DD Edit mode. Be sure to Save-As the model to work from a new copy if you experiment with modifying the geometry/zones in DD Edit mode.

Regards,
Bill

William Bishop, PE, BEMP, LEED AP

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I agree with Bill.

If you intend split the zone regardless in detailed edits, the attached illustrated guide from some time back may prove useful =).

~Nick

[cid:489575314 at 22072009-0ABB]

NICK CATON, P.E.

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Will combining the areas work for a LEED model?

-Stephanie

Stephanie Andersen

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Yes. ASHRAE Standard 90.1, Table G3.1, No. 7 describes the conditions that must be met to allow creating a thermal block from different HVAC zones. Condition c. is "All of the zones are served by the same HVAC system or by the same kind of HVAC system."

Regards,
Bill

William Bishop, PE, BEMP, LEED AP

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Good deal. You both have saved me a lot of headache!

Thanks so much!

Stephanie Andersen

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Joined: 2013-04-30
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