USE OM - JANUARY 2017
62
5.3.3.2.3
Height Constrained Psychrometric Testing Configuration
. If the
Laboratory Facility has height constraints when testing equipment with the full outlet
ASHRAE ducts, then whatever alternate configuration the Laboratory Facility may
utilize to measure these systems shall also be tested to validate against the setup in
Section 5.3.3.2.1.
5.3.4
Running the Test Procedure
.
5.3.4.1
Indoor air inlet conditions shall be those specified for the A test in AHRI Standard
210/240 Section 6.1.4.1 Table 3. These nominal conditions are 80°F DB and 67°F. Tolerances shall
also be per AHRI Standard 210/240.
5.3.4.2
Run each nominal standard airflow rate in Table K2 using only qualified nozzle
combinations for each of the configurations identified in Section 5.3.3.2 above. Airflow rate shall be
set to the test point and the measured reading shall be within ±1% of the airflow rate set point, as
specified in Table K2.
5.3.4.3
Test data for each point shall be recorded at equal intervals, with a maximum interval
period of one (1) minute, over a 30 minute period. Data will be averaged. For each set of test data,
there shall be a 30 minute pre-conditioning time.
5.3.5
Data to Collect
.
5.3.5.1
The following data is the minimum to be collected for this testing:
B
ST
= static pressure drop balance, %
P
a
= pressure, barometric, in. Hg
P
n
= pressure at nozzle throat, in. H
2
O
P
v
= velocity pressure at nozzle throat or static pressure difference across the
nozzle, in.H
2
O
Q
S
= measured air flow rate, SCFM
t
a1
= temperature, air entering indoor side, dry bulb, °F
t
*
a1
= temperature, air entering indoor side, wet bulb, °F
t
n
= nozzle temperature (if different than
t
a2
), °F
ΔPst,
A
= pressure drop, in.H
2
O
5.3.5.2
A data input template is located in Appendix D.
5.3.6
Interpretation and Application of the Data
.
5.3.6.1
Static pressure drop balance shall be calculated using the following formula:
B
ST
= (
ΔPst,
A
– Static Pressure from Table K2) / Static Pressure from Table K2*100
5.3.6.2
The external static pressure balance
B
ST
for each air flow rate shall be within ±7% of
the calibrated restrictor plate.
5.3.6.3
If
B
ST
is not within ±7%, then the code tester, instrumentation, etc. must be evaluated
and improvements made to the facility to bring it into compliance. All tests in Table K2 must be re-run
after any changes have been made.
5.3.6.3.1
If there are problems meeting this tolerance, then it is recommended that
Laboratory Facility run with the entering ASHRAE duct with the outlet configuration
that did not meet the tolerance, and then repeat the tests with the ASHRAE outlet
configuration and the inlet configuration that failed to meet the tolerance in order to
