Chapter 5
Pressure/Air Handler Flow Mode
Chapter 5 Pressure/Air Handler Flow Mode
5.1 Mode Summary
Mode
Application
Channel A Display
Channel B Display
Pressure/AH Flow
(PR/ AH)
Specialized mode for
measuring air handler
flow rates using a
TrueFlow Air
Handler Flow Meter
or a Duct Blaster fan.
Normal system operating
pressure (
NSOP
) and test flow
system operating pressure
(
TFSOP
) in Pascals.
Total air handler flow in units chosen
(CFM, m
3
/h, l/s). Air flow from the
selected Energy Conservatory test
device is continuously adjusted using
the measured
NSOP
and
TFSOP
readings from
Channel A
.
Note:
Appendix A
contains a Quick Guide for using the DG-700 with the
Pressure/Air Handler Flow
feature.
5.2 Overview of Pressure/Air Handler Flow Mode
The
Pressure/Air Handler Flow
mode is a specialized mode used to measure air handler flow with a TrueFlow Air
Handler Flow Meter or a Duct Blaster fan. The
PR/ AH
mode consists of the following 2-step procedure:
Step 1:
When first entering the
PR/ AH
mode,
Channel A
is set up to measure a Normal System Operating Pressure
(
NSOP
) in the duct system, under normal operating
conditions (e.g. existing filter in place, no test device
installed). Pressing the
START
button initiates a
long-term
average
NSOP
pressure measurement, and pressing
ENTER
records and enters the
NSOP
reading into the gauge.
Step 2:
Once the
NSOP
measurement is made and entered
into the gauge (
Step 1
), the gauge is set up to simultaneously
measure the Test Flow System Operating Pressure (
TFSOP
)
on
Channel A
, and to display the estimated air handler flow
rate on
Channel B
. The flow rate estimate shown on
Channel B
is determined by continuously adjusting the
measured air flow from the selected test device using a flow resistance correction factor calculated from the
NSOP
and
TFSOP
pressure readings.
(
Estimated Air Handler Flow
= Test Device Flow
x
Flow Resistance Correction Factor
)
Note:
TFSOP
is the operating pressure in the duct system, at the same location used for the
NSOP
reading, with
a TrueFlow Metering Plate or Duct Blaster fan installed.
TFSOP
is referred to in the TrueFlow Operation
Manual as the TrueFlow System Operating Pressure.
To select the
Pressure/Air Handler Flow
mode, press the
MODE
button until the selected operating
mode shown on the gauge display is
PR/ AH
.
5.3 Changing the Selected Test Device and Configuration
When in the
Step 2
part of the
PR/ AH
procedure, press the
DEVICE
button to select the
test device being used to measure air handler flow. When using the
PR/ AH
mode, the
TrueFlow Metering Plates (
TF
) and the Duct Blaster fans (
DB A
or
DB B
) are the only
compatible test devices.
19
Operating Instructions
for the DG700
Содержание DG-700
Страница 1: ...Operating Instructions for the DG 700 Pressure and Flow Gauge...
Страница 2: ......
