isolate which portion of the external static pressure measurement apparatus is out of
tolerance.
5.3.6.4 All Laboratory Certification Tests shall be performed only in Psychrometric Test
Facilities that have been verified to have B
ST
less than ±7%.
5.3.7 Reporting and Retention of the Data.
All data identified in Section 5.3.5 and calculated in Section 5.3.6 shall be reported for each run, and shall
be retained for a minimum of seven (7) years.
5.4 Full System Psychrometric Round Robin Testing.
5.4.1 Purpose of the Test. The purpose of the Full System Psychrometric Round Robin Testing is to verify
that all Psychrometric Test Facilities that may be used by a Laboratory yield consistent results. . Authorized
Laboratory Facilities shall be required to perform this Round Robin Testing on an annual basis.
5.4.2 Selection of Equipment.
5.4.2.1 Equipment Classification. In order to qualify the Laboratory Facility for both cooling
and heating, a single stage heat pump system shall be selected from the categories identified in Table
2 of AHRI Standard 210/240. Initial testing preference would be given to either a split system (HRCU-
A-CB) or a single package system (HSP-A). For repeat Round Robin Testing, alternate types of
systems shall be selected.
5.4.2.2 Equipment Size and Configuration. The system to be tested shall be selected from
AHRI 210/240 Certification Program samples previously tested at an existing Authorized Laboratory
Facility operating under contract with AHRI. The selected audit system shall be an OEM system and
shall have passed all certified values with at least 95% of the certified rating and if a split system, be
within ±10% on all condenser curves. The system type shall be a simple base model without
proprietary controls or other features that would complicate the testing. The nominal capacity of the
initial system would preferably be 3 tons. The size of the round robin system shall be rotated on a
yearly basis to ensure the entire application range is covered.
5.4.3 Test Setup.
Contact with the equipment manufacturer is permitted, and preferred, to validate correct set up prior to conducting
any Tests.
5.4.3.1 Test System Preparation/Charge. If the system is not pre-charged (e.g. a split
system), then during the cooling Tests the UUT shall be charged to match the previous audit data. In
order to match operating conditions, the refrigerant charge may be adjusted once during the heating
H1 Tests to match the outdoor subcooling results of the existing Authorized Laboratory Facility if
refrigerant subcooling leaving the condenser is greater than 1ºF different from the subcooling value
during the baseline test. The difference in charge, if any, shall be recorded in each case.
5.4.3.2 Test System Preparation/Cyclic. Cyclic testing shall be conducted using the same
time delays as used during the baseline testing, and shall use the mc
pm
determined in Section 5.2.6.
5.4.3.3 Secondary Capacity Check Type. For split systems, the preferred secondary energy
balance is the refrigerant enthalpy method as outlined in ASHRAE Standard 37 Section 7.5. For single
package systems, the outdoor air enthalpy method as outlined in ASHRAE Standard 37 Section 7.3.
If the psychrometric rooms are capable of both methods, then both energy balances should be
collected during the testing.
5.4.4 Running the Test Procedure.
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