ASHRAE Journal - February 2020 - 35

FEATURE

ASHRAE MTG.LowGWP
* Created in January 2012
* Includes expertise of multiple ASHRAE TCs, SSPCs,
and outside organizations
* Initially formed to coordinate activities related to
lower GWP refrigerants within the TCs, SSPCs, etc.
In 2016, it was given responsibility for direction and
management of several of the research projects on ﬂammable refrigerants, three initial projects that ASHRAE
committed to fund, plus more projects that followed.

output would look at the severity of the events by various relevant metrics such as the maximum temperature
and the maximum pressure that occurs. Finally, take the
simulation results and update the risk assessments with
the predicted severity data to give a total picture of the
risk.
In Phase 1, researchers discovered fundamental gaps
in the burning velocity database they needed as inputs
to their combustion models. It was necessary to perform
additional empirical work. These values were added to
the input dataset. Once the combustion models were
updated, researchers took seven or eight datasets from
researchers, simulated each scenario and compared
the experimentally measured values to the simulation
results. To ensure meaningful interpretation, they set up
a model evaluation protocol that considered both qualitative and quantitative rankings of the dataset and how well
the simulation from the CFD-model performed.
Discussion and evaluation indicated certain experimental datasets involving non-premixed combustion could
not be reliably used for model validation and more data
was necessary to ensure the CFD-model's accuracy in predicting consequence severity. Additional empirical testing and CFD-model validation were added to determine
how good the simulation model is in the context of combustion severity events needed for the risk assessment.
The additional experiments are in progress.
Once the CFD-model is updated and validated, a pilot
study was proposed to use the validated CFD-model to
predict the combustion consequences in context of these
risk assessments. The study is updating a previously
determined risk assessment for a given refrigeration
application and equipment type and analyzing risk differences of A3 and A2L refrigerants. The results are expected
to be released this summer.
The project's results have not yet been reviewed and
approved.

TABLE 1 Identified gaps in U.S. standards and guidelines.
TOPIC

KEY IDENTIFIED GAP AREAS

TRANSPORT OF FLAMMABLE Cylinder Theft Prevention, Proximity to Heat Sources
REFRIGERANT During Transit
HANDLING AND STORAGE Damage Protection, and the Location and Maximum
OF FLAMMABLE REFRIGERANT Quantities of Cylinders Allowed in Storage Areas
TRANSPORT OF SYSTEMS Limitations on Quantity of Systems Transported Per
CHARGED WITH FLAMMABLE Shipment, Structural Integrity of Refrigerant Systems,
REFRIGERANT and Damage Protection
PERSONNEL CERTIFICATION Safety Training and Certiﬁcation Requirements for

Installers and Technicians
OCCUPATIONAL SAFETY

Work Prior to Installation/Servicing-Notiﬁcation of
Servicing, Safety Radius Around Worksite, etc.
Work During Installation/Servicing-Electrical Component Repair, Response to Leakage Events, Leakage
Testing, Refrigerant Charging
Refrigerant Recovery/Venting-Venting Requirements
For Hydrocarbon Refrigerants and Compressor/Compressor Oil Replacement
Routine Testing And Emergency Procedures-Maintaining Open Air Passages and Entry Into Areas of
Refrigerant Leakage Detection
Acceptability of Brazing How and When Brazing May
Be Safe

SYSTEM Refrigerant Piping And Relief Devices-Non-Permanent
AND BUILDING DESIGN Fittings For Flammable Refrigerants, Access To Valves/

Joints, Relief Devices, and Discharge Quantities.
Ventilation Features and Functionality-Ventilation
System Power Supply/Circuitry, Ventilation Rate,
Operating Modes, and Fan and Duct Design
Combustion Equipment Co-Located With Refrigerant
System Clearance From Combustion Equipment
Refrigeration Leakage Detection and Alarms-Location
Of Leakage Detection Devices and Alarm Activation
Conditions. Ventilation Rates Recommended Levels of
Ventilation
Minimizing Buildup of Flammable Concentrations

RP-1807: Guidelines for Flammable Refrigerant Handling, Transporting,
Storing and Equipment Servicing, Installation and Dismantling
Contractor: Navigant Consulting; Principal Investigator:
William Goetzler
Introducing ﬂammable refrigerants in the U.S. market could increase the need for specialized processes,
training and/or certiﬁcations as part of risk mitigation.
Several countries have developed substantive ﬂammable
refrigerant requirements and best practices to address
handling, transport and storage of ﬂammable refrigerants and the installation, servicing and dismantling of
equipment using these refrigerants.
This research project investigated installation practices
as well as servicing and handling aspects for all equipment that uses A2, A2L and A3 refrigerants in domestic
FEBRUARY 2020

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ASHRAE Journal - February 2020

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