[BLDG-SIM] Dedicated outside air system with total heat recovery+separate VAV for cooling

Graham & Megan hamnmegs at ozemail.com.au
Fri Sep 1 18:23:40 PDT 2006


Assuming you are using EQuest based software you will have difficulty getting this set up the way you want.  TAS, Apache and I suspect TRNSYS and ESP will allow you to set this up the way you want on the airside.

With EQuest, if you can accept a constant off-coil temperature from your OA unit then set it up this way to guarantee humidity control, even reheat it to say 15C for a chilled beam system using a CW heat recovery coil and then pass this air to your main system using OA-FROM-SYSTEM.  I have done this and checked hourly reports throughly - it works.

The problems arise if you want to control your OA unit off-coil temperature on space humidity.  You will never get this just righ but you can try some approximations by setting the OA unit SAT on an outdoor air reset schedule and tune the reset parameters to get your space humidity levels where you want - iteratively lookign at hourly reports or possibly system humidity reports.

EQuest / DOE-2.2 are brilliant simulation tools that we enjoy for free.  I have been trying unsuccessfully in Australia to raise $ to get a few simple fixes made to the IU system humidity and heating controls that other systems with dewpoint control may also benefit from.  If anyone can see the value of making a financial contribution to enable Jeff Hirsch and his team to add more functionality in this area please contact Jeff or I.

Regards,
Graham
  ----- Original Message ----- 
  From: thulasi guptha 
  To: BLDG-SIM at GARD.COM 
  Sent: Thursday, August 31, 2006 11:44 AM
  Subject: [BLDG-SIM] Dedicated outside air system with total heat recovery+separate VAV for cooling


  Hi all,

  I am trying to model a dedicated outside air system with total heat recovery+demand controlled ventilation control and a separate VAV unit for cooling. The space needs to be maintained at 50% relative humidity. Any help will be greatly appreciated. 

  Thanks
  Thulasi



------------------------------------------------------------------------------
  Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates starting at 1¢/min.

===========================
You received this e-mail because you are subscribed 
to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe 
from this mailing list send a blank message to 
BLDG-SIM-UNSUBSCRIBE at GARD.COM
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20060902/6b746326/attachment.htm>


More information about the Bldg-sim mailing list