Baseline zoning

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Hi All,
I have VRV system which i will model as PVVVT system per zone in
proposed case. my baseline is chiller with PFP VAV should i model my
basline VAV system as system per zone like in proposed case VRV or i should
consider it as system per floor.

Regards
Sambhav

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Hello Sambhav,

According to ASHRAE 90.1-2007 G3.1.1 systems 5-8 are modeled with one system per floor, which I think your VAV falls under.

Byron D. Burns, EIT, BEMP

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Hi Sambhav,

I think your baseline system corresponds to system 8, so as you can see from ASHRAE 90.1-2007 G3.1.1, you should consider your baseline system as system per floor.

Regards,

Utku Simitli

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I sense 2 questions are being asked simultaneously, but only 1 has been answered?

? Baseline zoning should match the proposed design

? Baseline VAV/FPVAV systems should have one terminal unit per zone (matching proposed). All baseline VAV/FPVAV terminals on a given floor are served by a single central air handling unit, in your case with chilled water coils served by 1 or more baseline chillers. These elements together make up the ?system per floor.? In this way, you get one set of baseline supply/return fans to calculate per floor.

? Put another way: Baseline VAV systems are not intended to be modeled as a series of single zone systems, but rather as one air handling unit per floor serving one terminal unit per zone.

I might suggest considering the baseline FPVAV boxes as analogous to a VRV system?s cassettes: each cover the same area (zone) and use the same thermostat, but each is merely one component of a larger system.

Hope this helps,

~Nick

[cid:489575314 at 22072009-0ABB]

NICK CATON, P.E.

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