[Bldg-sim] Modeling PTAC system with economizer (E+)

[Joe Huang]

Qinpeng,

You might get responses to your question on the EnergyPlus_Support bulletin board than on 
BLDG-SIM.

Joe

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
www.whiteboxtechnologies.com
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"


On 6/6/2013 1:26 PM, Qinpeng Wang wrote:
> Hi, all,
>
> I'm trying to model a PTAC system with economizer within E+ environment.
>
> The specification of the system is:
>
> The OA economizer here is to provide "free" cooling during times of cool ambient 
> conditions. The amount of outside air taken into the building will vary between the 
> design percentage and the maximum percentage. And the design percentage of OA of the 
> system is not defined as related to occupancy or floor area but 25% of total supply air.
>
> I read the I/O reference about Controller:OutdoorAir, but it seems:
>
> "If all the limits are satisfied, the outdoor air controller does the following for 
> cycling fan systems: the outdoor air flow rate is set to the maximum when the fan cycles 
> on. If the limits are not satisfied, the outdoor air flow rate is at the minimum when 
> the fan cycles on."
>
> The problem is it's either minimum or maximum instead of modulating according to outdoor 
> and return air condition?
>
> Does anyone have suggestions on this? Help greatly appreciated.
>
> Do I have to go to EMS for this control scheme?
>
> Best,
>
> Qinpeng
>
>
> -- 
>
> Qinpeng Wang, PhD Student
>
> College of Architecture
>
> Georgia Institute of Technology
>
> Atlanta, GA 30332-0155
>
>
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20130607/7b5e2637/attachment.htm>