[BLDG-SIM] DOE-2 help ( I KNOW I have seen this before)..

[Graham & Megan]

John,
I have tried working around this in a number of ways and on a number of projects over the years.  While every project is unique, the best approximation in my opinion is to use the OA-FROM-SYSTEM command which passes return air (properties only not mass flow) from one system to another.  You assign the make up air system to a dummy zone with no loads and then need to control your supply temperature off a reset schedule.  Two problems / limitations are:
1) if your desired make up air temperature cannot be simplified to an outdoor air reset schedule then inaccuracies arise.  in this case run a couple of tests to bound the uncertainty.
2) if your tempering unit has bypass dampers to dehumidify while keeping dry bulb temperature elevated then this cannot be accurately represented in this case

If you are working in 2.1E and are familiar / adventurous with INPUT-FUNCTIONS then in theory you have ways to get around the problems above, but ...

I understand that Jeff Hirsch and gang may be working on adding in a better representation of minimum outdoor air / fresh air / make-up air systems.
Regards,
Graham
  ----- Original Message ----- 
  From: Aulbach, John 
  To: BLDG-SIM at gard.com 
  Sent: Saturday, June 19, 2004 3:07 AM
  Subject: [BLDG-SIM] DOE-2 help ( I KNOW I have seen this before)..


  I did such a DOE-2 run years ago, but now have forgotten how to do it.

  A building has outside air supplied by a tempering Makeup air (MAU) unit (could be anything-CHW or Package) to a plenum. All other building system draw from and return air to this plenum. The MAU has an economizer on it (or not).

  Does anyone have an example DOE-2 SYSTEMS input for this situation?

  Thanks in advance.


  John R. Aulbach, PE, CEM
  Project Engineer
  Sempra Energy Solutions
  555 West Fifth Street
  Mail Location 27F3
  Los Angeles, CA 90013
  Tel: (213) 244-8551 Cell (213) 219-4875

  "Sempra Energy Solutions is not the same company as SDG&E/ SoCalGas, the Utilities.  Sempra Energy Solutions is not regulated by the California Public Utilities Commission, and you do not have to buy Sempra Energy Solutions products or services to continue to receive quality regulated service from the Utilities."  



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