R-11 and R-113 Refrigerants: CFC Chiller Legacy Guide

\n\n

R-11 and R-113 Refrigerants: CFC Chiller Legacy Guide

Overview and History

R-11 (Trichlorofluoromethane) and R-113 (1,1,2-Trichloro-1,2,2-trifluoroethane) are both chlorofluorocarbon (CFC) refrigerants that played significant roles in the early and mid-20th century HVAC and refrigeration industries. Their development was driven by the need for safer, non-flammable, and non-toxic alternatives to earlier refrigerants like ammonia and sulfur dioxide. R-11 was first commercialized in 1932, and R-113 followed in 1934 [3]. These refrigerants, often marketed under the \"Freon\" brand, became widely adopted due to their favorable thermodynamic properties and perceived safety characteristics at the time.

The regulatory timeline for CFCs began to shift dramatically in the late 20th century with the discovery of their severe impact on the Earth\\'s stratospheric ozone layer. Research by Molina and Rowland in the 1970s highlighted the ozone-depleting potential of CFCs [30]. This led to international efforts to phase out their production and consumption. The Montreal Protocol on Substances that Deplete the Ozone Layer, signed in 1987, mandated a global phaseout of CFCs. In the United States, production of R-11, for instance, ceased on January 1, 1996 [6]. The phaseout of CFCs like R-11 and R-113 marked a pivotal moment in environmental policy and the HVAC industry, leading to the development and adoption of less ozone-damaging alternatives.

Chemical and Physical Properties

R-11 and R-113 are characterized by specific chemical and physical properties that made them suitable for various applications, particularly in low-pressure centrifugal chillers. However, their high Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) led to their eventual phaseout.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n

Property	R-11 (Trichlorofluoromethane)	R-113 (1,1,2-Trichloro-1,2,2-trifluoroethane)
Molecular Formula	CCl3F	C2F3Cl3
Molecular Weight	137.36 g/mol	187.4 g/mol
Boiling Point (1 atm)	23.77 °C (74.79 °F)	48 °C
ODP (R-11 = 1)	1.0 [4]	1.0 [4]
GWP (100-yr)	4,660 [11]	5,820 [11]
ASHRAE Safety Class	A1 [12]	A1 [12]

Note: ODP values are normalized to R-11, meaning R-11 has the highest ozone depletion potential. [81]

Applications Section

Both R-11 and R-113 were primarily utilized in low-pressure centrifugal chillers, which are commonly found in large commercial and industrial buildings for air conditioning and process cooling [refrigerantservicesllc.com/r-113-refrigerant/]. The high boiling points of these refrigerants allowed for system designs with lower operating pressures, simplifying mechanical requirements compared to systems using higher-pressure refrigerants like R-12 or R-22 [en.wikipedia.org/wiki/Trichlorofluoromethane].

R-11 was a staple in large centrifugal chillers, providing significant cooling capacity for extensive HVAC systems [hudsontech.com/refrigerants/our-products/r-11/]. Beyond refrigeration, R-11 also found use as a blowing agent for polyurethane foam insulation and as a cleaning/rinsing agent for low-pressure systems [en.wikipedia.org/wiki/Trichlorofluoromethane].

R-113 also saw widespread use in HVAC centrifugal chillers. Additionally, its excellent degreasing properties made it valuable as a precision cleaning solvent for delicate aerospace and electronic components, and as an aerosol propellant [refrigerantservicesllc.com/r-113-refrigerant/].

Legacy Refrigerants: Phaseout, Availability, and Alternatives

The phaseout of R-11 and R-113, driven by the Montreal Protocol, has significantly impacted their availability and legal status. Production in developed countries ceased in the mid-1990s, with a complete global phaseout of CFCs [6]. Consequently, new production and import of these refrigerants are banned, and their use is heavily restricted. Existing stocks are limited to reclaimed or recycled refrigerants, which are becoming increasingly scarce and expensive. The legal status generally prohibits their use in new equipment and mandates proper handling and disposal to prevent environmental release.

Recommended Modern Alternatives

The HVAC industry has transitioned to a range of alternative refrigerants with lower ODP and GWP values. For systems that historically used R-11 or R-113, the primary alternatives are often hydrochlorofluorocarbons (HCFCs) like R-123 (for R-11 systems) and later, hydrofluoroolefins (HFOs) or hydrofluorocarbons (HFCs) with very low GWP. The selection of an alternative depends on the specific chiller design, age, and desired efficiency.

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n

Feature	R-11 (CFC)	R-113 (CFC)	R-123 (HCFC)	R-1233zd(E) (HFO)
ODP	1.0	1.0	0.02	~0
GWP (100-yr)	4,660	5,820	79	1
ASHRAE Safety Class	A1	A1	B1	A1
Application	Low-pressure centrifugal chillers	Low-pressure centrifugal chillers	Low-pressure centrifugal chillers	Low-pressure centrifugal chillers
Status	Phased out	Phased out	Phasing out	Current alternative

R-123 (2,2-Dichloro-1,1,1-trifluoroethane) was a common interim replacement for R-11 in centrifugal chillers due to its similar thermodynamic properties and low operating pressure. However, R-123 is an HCFC and is also undergoing a phaseout under the Montreal Protocol, with production and import largely ceased in developed countries by 2020 [EPA.gov/ods-phaseout].

R-1233zd(E) (1-chloro-2,2,2-trifluoroethyl difluoromethyl ether) is a modern, ultra-low GWP (GWP=1) HFO refrigerant that has emerged as a viable long-term alternative for low-pressure centrifugal chillers, offering near-zero ODP and excellent energy efficiency [trane.com/content/dam/Trane/Commercial/global/about-us/decarbonization/REFR-PRB001-EN.pdf]. Its non-flammable (A1) safety classification makes it a preferred choice for many applications.

Transition Guides: Retrofit Procedures

Transitioning from R-11 or R-113 to modern alternatives in existing chiller systems requires careful planning and execution. The process typically involves a retrofit, which is more extensive than a simple drop-in replacement due to significant differences in refrigerant properties and system compatibility. Key steps include:

Refrigerant Recovery: The existing R-11 or R-113 must be completely recovered from the system using specialized equipment to prevent environmental release. This is a legally mandated step.
System Flushing: Thorough flushing of the chiller system is crucial to remove all traces of the old CFC refrigerant and its associated oil. Residual CFCs or incompatible oils can degrade the new refrigerant and lead to system failure. Multiple flushing cycles with appropriate flushing agents may be necessary.
Oil Change Requirements: CFC refrigerants typically used mineral oil. Modern alternatives like R-123 and R-1233zd(E) require different types of lubricants, such as polyolester (POE) oil. A complete oil change is essential, and multiple oil flushes might be needed to reduce the residual mineral oil to acceptable levels (typically below 1-5%).
Elastomer and Material Compatibility Checks: While R-11 and R-113 are generally compatible with common chiller materials, it\\'s important to verify the compatibility of seals, gaskets, and other elastomer components with the new refrigerant and oil. In some cases, certain components may need to be replaced to ensure long-term system integrity.
Component Modifications: Depending on the alternative refrigerant chosen, minor or significant modifications to the chiller may be required. This can include adjusting or replacing expansion devices, modifying compressor components, or updating control settings to optimize performance with the new refrigerant.
Leak Testing: After all modifications and charging, the system must undergo rigorous leak testing to ensure there are no leaks, as even small leaks can lead to significant refrigerant loss and environmental impact.
Performance Optimization: The chiller should be commissioned and optimized for performance with the new refrigerant. This involves adjusting superheat, subcooling, and other operational parameters to achieve optimal efficiency and capacity.

Safety and Handling

Handling R-11 and R-113, even as reclaimed refrigerants, requires strict adherence to safety protocols and regulatory requirements due to their ozone-depleting and global warming potentials. The principles of safe refrigerant handling apply, with added emphasis on containment and proper disposal.

Regulatory Requirements:

EPA Section 608 Certification: Technicians working with CFC refrigerants must hold EPA Section 608 certification (Type II or Universal) for proper handling, recovery, and disposal.
Refrigerant Recovery: It is illegal to knowingly vent R-11 or R-113 into the atmosphere. All recovery, recycling, and reclamation must be performed by certified technicians using certified equipment.
Disposal: Recovered R-11 and R-113 must be sent to EPA-certified reclamation facilities for proper destruction or recycling.

Equipment Needed:

Certified Recovery Machine: Specifically designed for low-pressure refrigerants.
Recovery Cylinders: DOT-approved, color-coded (yellow tops/gray bodies) for recovered refrigerants.
Vacuum Pump: To evacuate the system after recovery and before charging.
Manifold Gauge Set: Compatible with low-pressure refrigerants.
Leak Detector: Electronic leak detectors capable of sensing CFCs.
Personal Protective Equipment (PPE): Safety glasses, gloves, and appropriate respiratory protection (if exposure is possible).

Procedures:

Ventilation: Ensure adequate ventilation in the work area to prevent accumulation of refrigerant vapors.
System Isolation: Isolate the chiller from the rest of the HVAC system before beginning any work.
Refrigerant Recovery: Connect the recovery machine to the chiller and recover the refrigerant into designated recovery cylinders. Monitor pressure and temperature to ensure complete recovery.
Evacuation: After recovery, evacuate the system to a deep vacuum to remove non-condensable gases and moisture.
Charging (for retrofits): If retrofitting, charge the system with the new, compatible refrigerant and lubricant according to manufacturer specifications.
Leak Check: Perform a thorough leak check after any work involving opening the refrigerant circuit.

Record-Keeping:

Maintaining accurate records is a regulatory requirement. This includes:

Date and type of service performed.
Quantity and type of refrigerant recovered.
Quantity and type of refrigerant charged.
Identification of the recovery equipment used.
Name and EPA certification number of the technician.
Records of refrigerant sales and transfers.

FAQ Section

Q1: Why were R-11 and R-113 phased out?

A1: R-11 and R-113 were phased out primarily because they are chlorofluorocarbons (CFCs), which were found to be potent ozone-depleting substances. When released into the atmosphere, CFCs rise to the stratosphere and break down, releasing chlorine atoms that catalytically destroy the Earth\\'s protective ozone layer. This depletion leads to increased harmful UV radiation reaching the Earth\\'s surface. Additionally, both refrigerants have high Global Warming Potentials (GWPs), contributing significantly to climate change.

Q2: Can R-11 and R-113 still be used in existing equipment?

A2: While the production and import of new R-11 and R-113 have been banned globally under the Montreal Protocol, their use in existing equipment is generally permitted as long as the refrigerant is reclaimed or recycled. However, availability is scarce, and costs are high. Many regulations encourage or mandate transitioning to alternative refrigerants due to environmental concerns and the increasing difficulty of servicing older equipment.

Q3: What are the main differences between R-11 and R-113?

A3: Both R-11 and R-113 are CFC refrigerants used in low-pressure centrifugal chillers. The primary differences lie in their chemical structure and boiling points. R-11 (Trichlorofluoromethane) has a boiling point of 23.77 °C, while R-113 (1,1,2-Trichloro-1,2,2-trifluoroethane) has a boiling point of 48 °C. This difference affects their specific applications and the design of the chillers they were used in. R-113 also found more extensive use as a cleaning solvent due to its excellent degreasing properties.

Q4: What are the recommended modern alternatives for R-11 and R-113 chillers?

A4: For systems originally designed for R-11, R-123 (an HCFC) was a common interim replacement, but it is also being phased out. Modern, long-term alternatives include R-1233zd(E) (an HFO) which offers ultra-low GWP and near-zero ODP, making it an environmentally responsible choice for low-pressure centrifugal chillers. The best alternative depends on the specific chiller design and operational requirements.

Q5: What are the critical steps in retrofitting a chiller from R-11/R-113 to a new refrigerant?

A5: Retrofitting a chiller from R-11 or R-113 involves several critical steps: complete recovery of the old refrigerant, thorough flushing of the system to remove residual CFCs and old oil, a complete oil change to a compatible lubricant (e.g., POE oil), checking and potentially replacing elastomer components for compatibility, making necessary component modifications (e.g., expansion devices, compressor adjustments), rigorous leak testing, and performance optimization with the new refrigerant. These steps ensure the longevity and efficient operation of the retrofitted system.