Mechanical Upgrades / Replacement

Montgomery, AL
Jackson Hospital OR AHU Replacement

HHB Engineers was Prime AE for the replacement of AHU-27 and installation of desiccant outside air dehumidifier for AHU-22 and AHU-27.  Original system was installed in 1977 and serves OR-1 through OR-10.  Challenges included limiting OR downtime to two 2-day shutdowns. The $800,000 project included:

  • Replacement of AHU- 27 during two 2-day shut-down.  To accomplish this, new AHU was a roof mounted unit installed on roof of mechanical mezzanine.  Roof structure modified with additional beams and bracing. After removal of old AHU-27, DOAS-27 installed inside penthouse.  Wall opening closure using double exterior doors.
  • AHU-22 was replaced in 2009 and was 100% outside air.  System converted to re-circulating type by installing new return air duct from 2nd floor roof to 1st floor and up into bottom of OA plenum.
  • New DOAS-22 installed at grade with new outside air duct to first floor then paralleling new return air duct..
  • New DDC controls and re-heat control valves for all surgery rooms. And air handling units.
  • Steam pre-heat and desiccant regeneration coils.
  • All supply and return/exhaust ducts cleaned. (required two 2-day OR shut-downs, one concurrent with AHU-27 replacement)

Cost: $800,000

Completed: 2015