Page 1 of 2 12 LastLast
Results 1 to 13 of 18
  1. #1
    Join Date
    Feb 2008
    Posts
    78

    Bypass damper & DATS installed incorrectly?

    I noticed that the bypass damper on our new system (2 zone) is installed downstream of the zone dampers (only a foot or so after, but still after). The instructions say to install it upstream of the zone dampers. Is that a problem?

    Also, the DATS is installed directly in the silver box that the ducts connect to (don't know the name of that box!), which means in the line-of-sight of the air handler. The instructions say not to do that. Is that a problem? It's also installed in the same box mentione above, before the bypass damper (which is correct) but after the zone dampers. Is that correct?

    Shouldn't the correct set-up be:

    Air Handler> DATS > Bypass damper > Zone Dampers

  2. #2
    Join Date
    Mar 2003
    Posts
    1,877

    2 Zone

    bypass damper should be installed in the supply plenum just like the zone dampers.
    Also discharge air sensor also should be mounted in the supply plenum.

  3. #3
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    You are correct.
    Some times you can't install the DATS out of line of sight.
    So a sheild can be installed between the DATS and HX, to block the radiant heat.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  4. #4
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    Was the zoning an add on after the install began.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  5. #5
    Join Date
    Feb 2008
    Posts
    78
    Supply plenum - that's the silver box, correct?

    If so, then yes - both the bypass damper and the dtas, as well as the zone dampers, are all installed in the supply plenum. On the plenum, the install order is: zone dampers>DTAS>bypass damper. Everything was installed all at once.

    So it's okay that way, even with the DATS in the line of sight of the AHU? Is the shield you mentioned a necessity?

    Also, since they're all in the supply plenum, does that mean they're basically all at the same point of airflow, even though the DTAS and bypass damper are farther downstream within the supply plenum?

  6. #6
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    Yep, no problem.
    If they didn't install a shield. The DATS will heat up a little quicker, and the panel will shut the heat off to protect the HX.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  7. #7
    Join Date
    Jun 2008
    Posts
    393
    Honeywell zoning instructions call for the bypass damper to be installed upstream of the zone dampers.
    The DATS should be located in the supply trunk between the evaporator coil or heat exchanger and the first zone damper. If this is not possible, it is permissible to mount the DATS in the bypass duct.
    http://customer.honeywell.com/techli...0s/70-2321.pdf

  8. #8
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    They consider, the plenum part of the supply trunk.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  9. #9
    Join Date
    Feb 2008
    Posts
    78
    What is the plenum?

    From razorwit's reply, it sounds like it hasn't been installed properly. What's the general consensus - is it an acceptable install or something I should insist be changed?

  10. #10
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    Instead of lots of speculation on something we can't see.
    Take pics of it, and post them.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  11. #11
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    Quote Originally Posted by razorwit View Post
    Honeywell zoning instructions call for the bypass damper to be installed upstream of the zone dampers.
    The DATS should be located in the supply trunk between the evaporator coil or heat exchanger and the first zone damper. If this is not possible, it is permissible to mount the DATS in the bypass duct.http://customer.honeywell.com/techli...0s/70-2321.pdf

    never seen a dats installed in the bypass duct!

    and if i did i would move it!



    .

  12. #12
    Join Date
    Feb 2008
    Posts
    78
    I'm out of town this week - will post pics upon return.

    The manual for the dtas shows it installed in the bypass duct: will post manual link later.

    Why would you move it? Where is it normally installed - in the supply trunk? Isn't that always in the LOS of the AHU?

  13. #13
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,699
    It some times is, sometimes isn't.
    If its more then 3" away from teh HX, it can be in line of site.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event