[Equest-users] Under sized cooling coil

[Brad L. Huff]

All,

Thank you for your input. While the sizing factor did eliminate the unmet hours it did not correct the problem of e-Quest severely under sizing the system. The problem was related to the weather file and design conditions e-Quest was using. The weather file was correct for the climate zone but in examining the LS-C report, the cooling design conditions were 56 F Dry Bulb in September, far from the realistic design day of 91 F Dry Bulb in June. To correct this I created both a cooling and heating design day in the "Project & Site" tab.

Thank you,
Brad

Brad Huff, E.I.T., Mechanical Engineer I BVH Integrated Services I 860.286.9171 tel I 860.242.0236 fax I 50 Griffin Road South, Bloomfield CT 06002 I www.bvhis.com<blocked::www.bvhis.com>

________________________________
From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Eddie Corwin
Sent: Tuesday, October 19, 2010 5:26 PM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Under sized cooling coil

One quick and easy fix is to increase the sizing factor found in the cooling tab.  Currently you have it set to 1.15.  I tried setting it to 2.0, and there were no more unmet hours.

__________________________________________________________
Eddie Corwin, Energy & Sustainability Engineer
ALTANOVA - www.altanova-energy.com
41-41 24th Street - 4th Floor - Long Island City, NY 11101
T: (347) 410-9049
E: ecorwin at altanova-energy.com


________________________________
From: Brad L. Huff <BradH at BVHis.com>
To: "equest-users at lists.onebuilding.org" <equest-users at lists.onebuilding.org>
Sent: Tue, October 19, 2010 5:02:26 PM
Subject: [Equest-users] Under sized cooling coil
All,

I am modeling a portion of a 100% outside air lab in a type 5A climate zone. The area is below ground/has interior walls so there is no fenestration. The system has two chilled water air handling units and VAV boxes with zone reheat. The two AHU's run 24/7 at a constant CFM because the supply air is driven by a required air change rate per room type.
My problem is:
-     I have too many unmet cooling hours when allowing e-Quest to auto-size the cooling coil capacity of the air handling units
Diagnosis:
-          The delta T of the cooling coil never gets above 7 degrees F any day of the summer.
-          e-Quest severely undersized the cooling coils from a design day. (I have calculated the design day cooling load by hand)
-          No warnings in the Sim report

I have tried troubleshooting the system for a couple of days but am unable to find the reason e-Quest is under sizing the cooling coil capacity. I have attached the .inp file. Any suggestion are greatly appreciated.

Thank you,
Brad
Brad Huff, E.I.T., Mechanical Engineer I BVH Integrated Services I 860.286.9171 tel I 860.242.0236 fax I 50 Griffin Road South, Bloomfield CT 06002 I www.bvhis.com

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