Page 2 of 2 FirstFirst 12
Results 14 to 23 of 23
  1. #14
    Join Date
    Dec 2014
    Posts
    2,856
    Post Likes
    Daikin Rebel too I believe.

    Sent from my SM-G950U using Tapatalk

  2. #15
    Join Date
    Dec 2004
    Location
    Chicago area
    Posts
    8,378
    Post Likes
    Quote Originally Posted by WAYNE3298 View Post
    Lennox makes a unit with modulating hot gas reheat but I couldn't find one that would produce 50 F cooling coil discharge air. I think Aon and Munters both make such a unit but aren't they a lot more expensive?
    Probably alot more expensive


    Sent from my iPhone using Tapatalk

  3. #16
    Join Date
    Oct 2016
    Posts
    1,251
    Post Likes
    Daiken rebel, Trane horizon, Aaon “name” I can’t recall.

    Several units that can work in this situation.

    None are cheap. All can handle lots of outside air, cool it way down, reheat with discharge gas.

    There are more reasonably priced units with hg reheat for more normal duty. That is, not so much outside air.

  4. #17
    Join Date
    Oct 2016
    Posts
    1,251
    Post Likes
    And, the modulating hg is no biggy. The modulating compressor to keep the coil leaving temp at 50 is the big deal.

  5. #18
    Join Date
    Feb 2016
    Location
    Louisburg Kansas
    Posts
    3,469
    Post Likes
    Thread Starter
    Last I heard they are seriously considering AAON.
    Thanks and as always some good info given.
    No man can be both ignorant and free.
    Thomas Jefferson

  6. #19
    Join Date
    May 2018
    Location
    VA/DC
    Posts
    254
    Post Likes
    I have a building that has a Carrier 48LC VFD drive and 3 stages of cooling that work on a single evap.
    I run the first stage of cooling and modulate the vfd to get a 40 deg suction line temp. Im discharging at about 42 deg sat I then control the first stage of gas heat for reheat. I reheat based on space temp.
    with stage one cooling and a 34% vfd speed I don't have an issue over cooling.

  7. Likes CEAS-AC-TECH liked this post
  8. #20
    Join Date
    Nov 2001
    Posts
    167
    Post Likes
    Quote Originally Posted by Cool breeze 38 View Post
    I have a building that has a Carrier 48LC VFD drive and 3 stages of cooling that work on a single evap.
    I run the first stage of cooling and modulate the vfd to get a 40 deg suction line temp. Im discharging at about 42 deg sat I then control the first stage of gas heat for reheat. I reheat based on space temp.
    with stage one cooling and a 34% vfd speed I don't have an issue over cooling.
    Just curious - what is the reason for running such dry air?

  9. #21
    Join Date
    May 2018
    Location
    VA/DC
    Posts
    254
    Post Likes
    Quote Originally Posted by coolcoil View Post
    Just curious - what is the reason for running such dry air?
    this unit serves a high body count 30x60 room. The demand for fresh air to maintain 775 ppm co2 is about 35% damper. Most of the year the humidity is about 65% So they asked to make the unit dehumidify.
    The room is in the middle of a data center so the load is low.

    If i run the fan faster but have a warmer discharge air I tend to overcool at that point then needing heat. We watched it for a few days with trending and such and found the sweet spot.

  10. #22
    Join Date
    Feb 2016
    Location
    Louisburg Kansas
    Posts
    3,469
    Post Likes
    Thread Starter
    Coolcoil the reason is this is a nursing home and it generates a lot of humidity. The unit will serve the purpose of humidity control and building pressurization. It will have a heat wheel and should save them energy. At present they are pressurizing the building with raw outside air. By raw I mean no energy recovery.
    No man can be both ignorant and free.
    Thomas Jefferson

  11. #23
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    31,510
    Post Likes
    You may want to check with IT about what level of humidity is preferred.

    35% sounds low to me.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist
    Member, IAEI

    AOP Forum Rules:







Page 2 of 2 FirstFirst 12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •