Design review / design build: MDF room packaged HVAC unit/system

Engineered Systems, August, 2007 by Amanda McKew

Job number:
Area served: Main distribution frame (MDF) room
Equipment type: Packaged HVAC unit
Equipment Designation: CACU-1
Barcode designation: 11111
Equipment location: In occupied space

DESIGN REVIEW                                              [Y]   [N]

* Verify adequate equipment room ventilation.              ()    ()
* Spot-check air quantity by determining cfm/sq ft.        ()    ()
* Spot-check heating capacity by determining Btuh/sq ft.   ()    ()
* Spot-check cooling capacity by dividing total cfm by     ()    ()
  400 = tons and OA cfm by 300 for dehumidification
  tons.
* If underfloor air system is utilized, confirm there      ()    ()
  are enough perforated tiles in the floor for adequate
  airflow.
* Create system flow diagram to assess static pressure     ()    ()
  sequence of operation, condenser water, and/or chilled
  water pressure drops.
* Spot-check fan total static pressure by comparing with   ()    ()
  fan total static pressure of inch based on dirty
  filters (prefilter + after filter + final filter).
* Review if unit is chilled water, DX condenser water      ()    ()
  with DX, or dry cooler-based.
* Confirm coils are piped correctly per manufacturer's     ()    ()
  piping requirements.
* Review specifications to confirm space humidity/         ()    ()
  temperature setpoints are specified and within high/
  low alarm limits.
* Review specifications and confirm alarm delay duration   ()    ()
  is specified 0 to 255 seconds.
* Review specifications to determine if unit or floor      ()    ()
  leak detection was specified.
* Review control drawings and specifications to            ()    ()
  determine if unit will be tied to an AC or universal
  panel.
* Review control drawings and specifications to            ()    ()
  determine if unit will operate as a standalone unit,
  on a network or BAS/BMS.

ELECTRICAL INSPECTION/REQUIREMENTS                         [Y]   [N]

* What are the new electrical requirements for the new     ()    ()
  CACU?
* Is there adequate electrical power to meet new           ()    ()
  electrical load from CACU?
* Will emergency power be a requirement for the new        ()    ()
  CACU?
* Are electrical connections tight and secure?             ()    ()
* Have the fuses and wire sizes been checked and           ()    ()
  verified?
* What electrical system components (existing conduits,    ()    ()
  light fixtures, panels, etc.) will require removal,
  reinstallation, and/or relocation?
* Are there existing electrical code issues that should    ()    ()
  be address at this time?

HVAC INSPECTION/REQUIREMENTS                               [Y]   [N]

* Has selection of CACU been approved and signed off by    ()    ()
  owner?
* Have cold/hot water management system been completed     ()    ()
  in an automatic control-functional performance action
  /reaction matrix?
* Have gpm-pressure drop-velocity been noted on            ()    ()
  distribution points of the water piping flow diagrams?
* Have pump curves been assessed for optimum               ()    ()
  performance?
* Verify that water piping is complete and correct         ()    ()
* Can the CACU be installed with access for maintenance?   ()    ()
* Has consideration been given to future expansion of
  system?
* Has system flushing been determined in scope of work?    ()    ()
* Has condensate drain piping be addressed?                ()    ()
* Has consideration be given to the manufacturers'         ()    ()
  recommended clearance around equipment for service?
* Has hot corridor / cold corridor been considered?        ()    ()

PLUMBING REQUIREMENTS                                      [Y]   [N]

* Have floor drains been coordinated?                      ()    ()
* Have backflow preventors been considered?                ()    ()
* Has a water filter been considered for city water to     ()    ()
  humidifier?

GENERAL CONSIDERATIONS/REQUIREMENTS                        [Y]   [N]

* What are the necessary installation permitting and       ()    ()
  operation permitting requirements?
* Will record drawings be submitted electronically along   ()    ()
  with one paper copy?
* Will there be an extended warranty on the equipment?     ()    ()
* Will there be a service contract submitted for the new   ()    ()
  CACU?
* Will CACU O&M website be included along with             ()    ()
  electronic copy or O&M manual and two paper copies of
  manual?

If you have any comments, suggestions, or questions regarding this designer checklist, contact Amanda McKew at amckew@rdkengineers.com.

This column is meant to provide some basic guidelines for good design. Always consult all necessary codes and resources relevant to each particular project.