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Grant Laidlaw is currently the owner of the Air Conditioning and Refrigeration Academy (ACRA) in Edenvale. He holds a Bachelor of Business Administration and an associate degree in educational administration. He has a National Technical Diploma and completed an apprenticeship with Transnet. He has dual-trades status: refrigeration and electrical. He has been involved with SAIRAC for over two decades and served on the Johannesburg committee as chairman and was also president between 2015 and 2018. Currently he is the SAIRAC national treasurer.

Many people ask for assistance in the understanding of theoretical and practical aspects of the industry. We are going back to basics as I have questions coming in that indicate that the basic understanding necessary to work in the industry is not in place.

R-1234yf is a hydrofluoroolefin refrigerant (HFO) with the chemical name Tetrafluoropropen. HFO refrigerants are composed of hydrogen, fluorine and carbon atoms, but contain at least one double bond between the carbon atoms. Due to its composition, R1234yf does not damage the ozone layer and has minimal global warming impact.

R-1234yf (HFO-1234yf) is the market replacement for R134a in automotive type applications. This substance is similar in cooling performance to R134a, while having a global warming potential (GWP) of 1 compared to R-134a’s GWP of 1.430. This refrigerant falls into the ASHRAE category A2L – mildly flammable. The temperature at which HFO-1234yf ignites is fairly low (405ºC) and when it burns it produces hydrogen fluoride, which, when it comes into contact with water, is transformed into hydrofluoric acid, a highly toxic and corrosive substance.

As a result, some additional safety measures should be implemented when using this refrigerant.

Main characteristics of R-1234yf:

• Low toxicity
• Low GWP; GWP = <1
• Zero ozone-depleting potential
• Class A2L refrigerant – mildly flammable
• Low total contribution to climate change

Working environment

In general, all ignition sources including open flames, electric arcs formed by switch gear, single phase motors or any heat sources should be at least 2.5m away from the work area.

Work in a well-ventilated area with extract ventilation and a fan to dissipate any refrigerant leakage.

Note: currently it is difficult to get A2L compliant vacuum pumps. A typical vacuum pump used with fluorinated refrigerants can be used when evacuating a R-1234yf system by placing a service hose on the vacuum pump outlet and placing the hose outlet in a well-ventilated space – or preferably outdoors.

Switch pump on and off at the wall socket rather than the on/off switch on the pump itself.

Equipment needed for R-1234yf

The general requirement for R-1234yf tools is that they are ‘ignition proof’. Ignition proof tooling provides a spark free tool/work environment. This reference is relevant to any tool that has electrical requirements.

• An R-1234yf calibrated gauge set with dedicated R-1234yf couplers. As R-1234yf is an A2L mildly flammable substance, SAE standards have been developed for hoses and couplings.
• Red and blue service hoses: the fittings are 12mm O Ring fittings male with a hexagon nut. R-134a is ½” female. R-12 – commercial industry standard – is ¼” flare female with a knurled nut.
• R-1234yf has a unique vehicle quick release fitting, to prevent use of incorrect equipment not fit for this type of refrigerant.
• Yellow service hose ½” LH acme thread. An adaptor is available to fit a universal vacuum pump.
• The manifold gauge set is designed to take the male fittings of the hose set and are calibrated to read R-1234yf temperatures.
• Electronic refrigerant leak detector A2L compliant.
• Vacuum pump A2L compliant.
• Recovery/reclamation equipment A2L compliant. Although it is not mandatory to recover R-1234yf, it is still good environmental practice and due to the cost of this refrigerant it would be advisable to do so.
• Dedicated cylinders for recovered or new R-1234yf have a left-hand valve thread and require a suitable adaptor to connect to the gauge set charge hose. As R-1234yf is a mildly flammable gas, cylinder storage and transport practices differ to R-134a cylinders.

Is R-1234yf compatible with existing R-134a equipment?

No. The R-1234yf system refrigerant circuit is accessed using service couplers that are a different size to those of a R-134a system. The service coupler hose connection also has a left-hand thread that requires a matching hose for connection. Hence the need for an R-1234yf gauge set.

R-1234yf is classified as an A2L mildly flammable refrigerant and requires the use of equipment designed for use with such a refrigerant. The exception is an electronic leak detector. Several manufacturers produce detectors that are suited to both refrigerants.

Can a R-134a system be converted to R-1234yf?

No. R-134a systems were not designed to operate using a flammable refrigerant. R-134a systems should not be converted to use R-1234yf as these systems are unable to be converted to a level that satisfies the requirements of international standards set for systems that use R-1234yf. The standards lay down specific requirements for system design. For example, the R-1234yf evaporator is significantly stronger than the one you would commonly find in an R-134a system.

Aside from the safety aspects, although the two refrigerants have similar thermodynamic properties, they are not the same. Therefore, compressor damage or system performance limitations may be experienced by attempting to convert an R-134a system to R-1234yf.

Do I need an SAQCC Gas authorisation and licence to handle R-1234yf?

Yes, safe handling authorisation and registration is required. It is a legal requirement that any person working with a refrigerant with operating pressures exceeding 50kPa be a registered authorised refrigeration practitioner in the relevant category.

Safety issues to be aware of when handling R-1234yf

R-1234yf is classified as A2L mildly flammable. Technicians need to take the relevant safety measures for the correct transport, storage and handling of a flammable gas. This would include, but is not limited to, adequate ventilation, ensuring no open flames and electric arcs are within 2m of the system.

Note: highly toxic substances are created when this gas is burnt and must not be inhaled.

Asphyxiation and freeze burns are also a risk. It is advised to refer to the relevant material safety data sheets available from your refrigerant wholesalers for specific safeguards when handling this refrigerant. Suitable personal protective equipment (PPE) is to be worn when handling this refrigerant. Static discharge can be limited by wearing cotton overalls. Suitable trade training in flammable refrigerants is recommended prior to working on systems containing flammable refrigerants.

Let us look at what to do when exposed to a leak.

First aid

Eye contact:

• If a product comes in contact with eyes, remove the patient from gas source or contaminated area.Take the patient to the nearest eye wash, shower or other source of clean water.
• Open the eyelid(s) wide to allow the material to evaporate.
• Have the patient lie or sit with the head back. Hold the eyelid(s) open and pour water slowly over the eyeball(s) at the inner corners, allowing the water to run out of the outer corners. Gently rinse the affected eye(s) with clean, cool water for at least 15 minutes.
• Ensure that the patient looks up, and side to side as the eye is rinsed in order to reach all parts of the eye(s).
• Transport to hospital or doctor.
• Even when no pain persists and vision is good, a doctor should examine the eye as delayed damage may occur. If the patient cannot tolerate light, protect the eyes with a clean, loosely applied bandage.
• Ensure verbal communication and physical contact with the patient.
• Patient must not rub the eyes or tightly shut eyes. Only use cold water, not warm or even tepid water. Do not apply any medication, eye drops or the like.

Skin contact:

• Immediately remove all contaminated clothing, including footwear.
• Flush skin and hair with running water and soap, if available. Seek medical attention in event of any irritation.
• For frostbite: place the exposed area in a warm water bath (41-46 C) for 15-20 minutes, and seek medical attention.

Ingestion

• Not considered a normal route of entry.
• Avoid giving milk or oils. Avoid giving alcohol.

General (trained first aider should be present)

• Following exposure to gas, remove the patient from the gas source or contaminated area.
• Prostheses such as false teeth, which may block the airway, should be removed, where possible, prior to initiating first aid procedures.
• If the patient is not breathing spontaneously, administer rescue breathing. If the patient does not have a pulse, administer CPR. If medical oxygen and appropriately trained personnel are available, administer 100% oxygen. Call for an ambulance. If an ambulance is not available, contact a physician, hospital, or Poison Control Centre for further instruction and transport. Keep the patient warm, comfortable and at rest while awaiting medical care. Administer rescue breathing preferably with a demand-valve resuscitator, bag-valve mask-device, or pocket mask as trained, or CPR if necessary.
• Monitor breathing and pulse continuously.

Fire

• Evacuate work area.
• Do not extinguish burning gas unless leak can be stopped safely, if not leave gas to burn.
• Small fires: Dry chemical, CO2 or water spray to extinguish gas – only if absolutely necessary and safe to do so.
• Large fires: DO NOT use water jets directly on fire.
• Cool cylinders by direct flooding of water onto upper surface until the fire is extinguished.
• Call fire department.

Gareth, I hope that this increases your understanding of R-1234yf. The world is moving onto more environmentally friendly refrigerants which require us to alter our thinking, processes, and procedures accordingly.

Thanks to everybody for the overwhelming response. I receive many questions each month and cannot publish all of them. Keep them coming, as I may answer you directly. Looking forward to hearing from you.

REFERENCES:

1. SETA training
2. ASHRAE
3. ACRA
4. A-Gas