ASHRAE Journal - April 2014 - 46

Technical FeaTure

contractor's foreman and project
manager about the project's various
contract requirements. For example,
during the meeting, each contractor's foreman and project manager
should be required to answer several
detailed questions, such as:
* What will they do differently in
the construction process at each
duct pressure change?
* How will they seal the ducts at
each different pressure class?
* How will they pressure-test the
ducts to show compliance with the
leakage specs?
* How will they determine the
actual class of a specific duct
section?
* How will they ensure that transitions and offsets are not choked with
airflow restrictions?
* How will they ensure that transitions have the proper slope-and are
sloped at less than the 30-degree
angle mandated by the SMACNA?
* What is their plan for installing
VAV boxes, diffusers, and related
equipment?
The CxA's mission during prefunctional testing-on behalf of the
owner-is to proactively identify and
stop problems before they become
integrated into the building. So if a
contractor representative gives an
answer that doesn't align with the
contract requirements, be sure to
use that occasion to show the contractor the proper way to install the
system or component in question.

form 2 Variable air volume field installation verifications.
Pre-functional tests for VaV box #

A properly sized VAV box is installed in the correct location.
The VAV box is installed in the proper flow direction.
The VAV terminal inlet size conforms to the shop drawings.
The VAV box is installed with 4 diameters of straight inlet duct (or per manufacturer recommendations).
Factory-supplied VAV measuring devices are properly installed.
The VAV damper can physically open and close.
An access door is installed by the reheat coil.
The reheat coil is visually clean and fins are undamaged.
PiPing contractor Verifies that:

Flow fittings are installed in the proper flow direction and are accessible for
testing.
The control valve and circuit setter are on the leaving-water side of the coil.
Flow fitting tags are installed with proper flow information.
Coil venting is properly installed.
Valves are correctly installed.
controls contractor Verifies that:

The inlet size of the VAV box that has been stored in the energy management
system (EMS) matches both the inlet size shown on the shop drawings and the
size that was actually installed.
The proper area-correction factor has been entered into the EMS.
The correct VAV terminal and ID numbers have been entered into the EMS.
The correct occupied and unoccupied minimum and maximum airflow values
have been entered into the EMS.
The required flow offset value has been entered into the EMS.
The thermostat is located in a position that will accurately measure room
temperature.
The temperature sensor is not affected by temperature differences in the wall
cavity.
The proper minimum/maximum set points from the approved shop drawings have
been entered into the EMS.

In traditional process commissioning, the CxA
observes, documents, and records problems. But the
technical commissioning process is much more interactive, working to ensure the building is properly constructed from the ground up.
ASHRAE JouRnAl

ashrae.org

issue log #

sheet metal contractor Verifies that:

Process Commissioning vs. Technical Commissioning

insPector

Apri l 2014

In process commissioning, each contractor serves as
the subject matter expert (SME) for their specific trade
during their pre-installation meeting, while the CxA
serves as the SME for only commissioning-specific functions. But in technical commissioning, the CxA serves
as the SME during the pre-installation meeting. This

ASHRAE Journal - April 2014

Table of Contents for the Digital Edition of ASHRAE Journal - April 2014