[Equest-users] Problem of design flow rate autosize

[Keith Swartz]

Hello, Yu,

The difference may be due to eQUEST’S air density correction based on the elevation of your project location. The auto-calculated value is adjusted for the altitude. The air flow you enter is assumed to be at sea level (standard conditions). If this density correction calculation is causing the difference you see, then changing the elevation to 0 feet should get them to match.  To change the elevation, in the Detailed Interface click on “Project & Site” in the upper left, then in the Component Tree on the left side double-click on “Site Data” (4th one down from the top). The field for Altitude is near the middle of the Basic Specifications tab.

________________________________
Keith Swartz, P.E., LEED AP

Energy Engineer / Senior Project Manager
Energy Center of Wisconsin
455 Science Drive, Suite 200, Madison, WI 53711
Phone: 608.238.8276 x123
Fax: 608.238.0523

The Buildings Team
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From: 刘宇 [mailto:elaneinside at hotmail.com]
Sent: Sunday, July 10, 2011 10:34 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Problem of design flow rate autosize

Hi

I’m trying to model baseline system 7 HVAC system using ‘Variable Air Volume’ system with zone HW reheat. When I leave design supply flow blank to let equest auto size, I have 60343 cfm supply flow and 320 unmet heat hour in system summary table. But when I input 60343 cfm in system design flow box and recalculate, then I have 105 unmet hours, and nothing else changed in system summary table. Is that a bug of software or there are some reason I don’t know.

Yu Liu
+8615010414883
elaneinside at hotmail.com

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