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  1. #1
    Join Date
    May 2012
    Posts
    21

    first VAV start up

    Need a little help.

    company i work for is doing an inhouse renovation project. took a room that was used for file storage and making it into a workspace. we demo'ed out the old VAV, and put in a bigger box. I saved the old (siemens BACnet) TEC, damper, and HWV. it will be the same application. just will be adding a CWV. my question is, we upsized the duct from 6in round to 8in round from the trunk line to the new VAV. they want to achieve a maximum cooling CFM of 450CFM for this box. i know i need to change the duct area subpoint. what other points do i need to change for a proper set up? thanks

  2. #2
    Join Date
    Jul 2011
    Location
    East coast USA
    Posts
    961
    min max settings if you have them. does it have a flow tube?

  3. #3
    Join Date
    May 2012
    Posts
    21
    i already have the MIN and MAX CFM settings put in the TEC and on the initial values. it does have a flow tube with Hi and Lo going back to the TEC. i suppose my only real concern is setting up the TEC is making sure i have the balancing set up right so i know that the CFM reading i am getting is correct.

  4. #4
    Join Date
    Nov 2006
    Location
    SE Wisconsin
    Posts
    313
    Flow coeffecient, cooling and heating min and max, duct size come to mind.

    Did you say you're adding a chilled water valve? If there was not one there previously, you just changed the application. That changes more thing, possibly. Why would you be adding a cwv to a VAV? Isn't the ahu supplying the cooling?

    Just the thoughts off the top of my head.

  5. #5
    Join Date
    May 2012
    Posts
    21
    yeah Im adding a CW zone valve for chilled beams. all the VAVs on our site were flashed by siemens over the summer with the same application to speed up the PID loop for chilled water. I have been messing with the duct area and flow coeff settings. i have already put the min and max heat cool settings in. i am thinking that i wont really get to know if the box is reading correctly until they send out balancers.

  6. #6
    Join Date
    Nov 2006
    Location
    SE Wisconsin
    Posts
    313
    Are you generating any PPCL to control the CW out of the VAV's or are you expecting the application to manage it? Did the original application have CWV contol?

  7. #7
    Join Date
    May 2012
    Posts
    21
    The TEC will control the CWV. Only PPCL i will need to write is a table statement for the dewpoint sensor that will be hooked up to AI3.

  8. #8
    Join Date
    Nov 2006
    Location
    SE Wisconsin
    Posts
    313
    May I ask what application you have running in the TEC now? I'm curious...

  9. #9

    TEC application

    I use SIEMENS extensively. I don’t have an off the shelf Application that will do CHW, Damper and HW Reheat. are you using custom application? I have most of the Applications and TEC capability’s saved in files on my desktop. I’d be happy to share. Post the sequence you hope to accomplish and I’ll look for an appropriate TEC and application.



    Quote Originally Posted by BASguy99 View Post
    Need a little help.

    company i work for is doing an inhouse renovation project. took a room that was used for file storage and making it into a workspace. we demo'ed out the old VAV, and put in a bigger box. I saved the old (siemens BACnet) TEC, damper, and HWV. it will be the same application. just will be adding a CWV. my question is, we upsized the duct from 6in round to 8in round from the trunk line to the new VAV. they want to achieve a maximum cooling CFM of 450CFM for this box. i know i need to change the duct area subpoint. what other points do i need to change for a proper set up? thanks

  10. #10
    Join Date
    May 2012
    Posts
    21
    Quote Originally Posted by Myvz800 View Post
    I use SIEMENS extensively. I don’t have an off the shelf Application that will do CHW, Damper and HW Reheat. are you using custom application? I have most of the Applications and TEC capability’s saved in files on my desktop. I’d be happy to share. Post the sequence you hope to accomplish and I’ll look for an appropriate TEC and application.
    The application is 2558. BACnet VAV with demand control ventilation(CO2) including Chilled beam and floating or analog output.

  11. #11
    Join Date
    May 2012
    Posts
    21
    Does anyone have WCIS?

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