Thanks for your comments. I am trying to input natural ventilation rates in an attic calculated by another program; therefore, I don't want any mechanical effects like fan heat, forced air flows, or conditioning. It seemed to me once those are deactivated, the ventilation object should be functionally identical to the infiltration object, but I just wanted to make sure.
With my application where I'm inputting the flow rates via an hourly schedule file, the "Design Flow Rate" is just a dummy variable, so I thought 1.0 would be the easiest to understand. I definitely don't want the resultant flow rate to be a constant 1.0, that would make my exercise completely meaningless!
Joe
On 10/8/2013 5:46 AM, Jim Dirkes wrote:
Dear Joe,
A few thoughts:
· Infiltration comes directly from outdoors with no conditioning. I have not used the ventilation object, but it appears to do the same, except oriented to natural ventilation. If you want outdoor air with no conditioning, fine. I generally think of “ventilation” as conditioned air, however.
· To make a constant flow rate, you would use the “Design Flow Rate” in the either object, with coefficients as you describe
· I’m not sure why you want to set the rate to 1.0 m3/s. It seems that’s going to vary by zone and would not likely be 1.0.
James V Dirkes II, PE, BEMP, LEED AP
www.buildingperformanceteam.com
Energy Analysis, Commissioning & Training Services
1631 Acacia Drive, Grand Rapids, MI 49504 USA
616 450 8653
From: EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of Joe Huang
Sent: Monday, October 07, 2013 8:44 PM
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
Subject: [EnergyPlus_Support] What's the difference between the ZoneInfiltration:DesignFlowRate and the ZoneVentilation:DesignFlowRate object?
Time for me to ask a question.
I want to take the ventilation rate from another program and feed it into EnergyPlus without any modifications. Looking through the IDD, it seems I can do this using either the ZoneInfiltration:DesignFlowRate or the ZoneVentilation:DesignFlowRate object, but in either case I would have to disable the temperature and velocity coefficients by setting them to 0, leaving the constant term as 1.0. Likewise, I would use flow/zone as the calculation "method" with t he rate set to 1.0. Does anyone see any problem in doing this, and whether there is any difference between the two objects when used in this manner ?
Thanks for any comments or suggestions.
JoeJoe HuangWhite Box Technologies, Inc.346 Rheem Blvd., Suite 108DMoraga CA 94556yjhuang@xxxxxxxxxxxxxxxxxxxxxxxxhttp://weather.whiteboxtechnologies.com for simulation-ready weather data(o) (925)388-0265(c) (510)928-2683"building energy simulations at your fingertips"
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