Refrigeration tool list: what technicians and CO2 installers need

How to use this list

The list names tool types, not products. Two questions decide most choices: what pressure the tool will see, and whether the refrigerant is flammable (A2L or A3). Chemours notes that many tools are the same for A2L as for R-410A, but tools with electrical parts or motors should be designed for mildly flammable refrigerants ^[1]. In the EU, Article 10 of Regulation (EU) 2024/573 requires certification for this work, natural refrigerants included where relevant ^[7], and the practical exam is done with the relevant tools ^[8].

1. Manifold gauges and hoses

The manifold and hoses are used to read pressures, charge and evacuate. Check the maximum working pressure of the gauges, the manifold body and every hose, and that the gauge covers your refrigerant. For A2L these are routine tools ^[1].

CO2 is different. The transcritical discharge pressure is about 80-120 bar, and in the Danfoss example system the high side has a maximum allowable pressure (PS) of 130 bar ^[2]. High-side gauges and hoses must be rated at least for the PS on the nameplate. The low side also needs a margin, because the standstill pressure can be much higher than the suction pressure ^[2]. Danfoss states that all tools and hoses should be rated for the pressure of the R744 system ^[3].

2. Vacuum pump and micron gauge

The vacuum pump removes air and moisture before charging. Match its capacity to the system volume and keep the oil clean. For A2L, Chemours lists a pump with its switch located away from the work zone ^[1]. For CO2, the same pump can be used if it is charged with ester oil ^[2]. A micron gauge on the system shows the real vacuum, which manifold gauges cannot; a common target is below 500 microns ^[5].

3. Leak detectors

For halogenated refrigerants, choose an electronic detector tested to EN 14624: the 2020 edition requires a sensitivity of at least 5 g per year, with regular checks against a calibrated reference leak ^[4]. For A2L, Chemours lists a detector certified for 2L ^[1]. For A3 and CO2, use a detector intended for that refrigerant. Keep leak detection fluid to pinpoint the leak.

4. Charging scale

Refrigerant is charged and recovered by weight, and the amounts go into the records. Check the capacity against your largest cylinder and the resolution against your smallest charge. Choosing the correct type of scales is an EU exam item ^[8].

5. Recovery machine and cylinders

• Recovery machine. Check which refrigerants and pressures it is approved for. For A2L it should be certified for 2L ^[1].
• Cylinders for A2L. Returnable cylinders with a flammable GHS label and a left-hand valve thread, where R-410A cylinders have a right-hand thread. Chemours gives a minimum pressure rating of 42 bar and DIN 477-1 as the typical valve type ^[1].
• General rules. Use proper recovery cylinders only, never heat a cylinder above 52 °C, and never connect one to the discharge side ^[1].
• CO2. The EU exam for CO2 covers the special requirements for cylinders and double valves ^[8].

6. Nitrogen with a pressure regulator

Dry, oxygen-free nitrogen is used for strength and tightness tests and for purging; never oxygen or compressed air ^[6]. A2L systems must not be pressurised with air for leak testing ^[1]. Use a regulator with a relief valve after it. For CO2 the test pressure can be 1.43 × PS ^[2], so the regulator and hose must be rated for that.

7. Brazing equipment

A torch set, brazing alloy and nitrogen for purging. On A2L systems, recover the refrigerant, purge, leave the system open, ventilate, and stop if the flame grows or changes colour ^[1]. On CO2, do not braze until the system is fully depressurised ^[3]. Chemours lists a chemically compatible dry powder or CO2 fire extinguisher for A2L work ^[1].

8. Tube tools

A tube cutter for square cuts, a deburring tool for the inner burr, a flaring tool with a torque wrench for flare nuts, and a tube bender for bends without kinks. For A2L these are routine tools ^[1]. For CO2, the tubes and fittings must be rated for the pressure.

9. Electrical test tools

• Two-pole voltage tester to EN 61243-3 for proving dead, checked on a proving unit before and after use. Non-contact testers must not be used to prove dead ^[9].
• Clamp meter for compressor and fan currents, built to the EN 61010 series and marked CAT II, III or IV; CAT III covers distribution boards and fixed equipment ^[9].
• Probes and leads with finger barriers and at most 4 mm exposed tip, preferably 2 mm ^[9].
• Insulation resistance tester for windings and cables on de-energised equipment, covered by IEC 61557-2 ^[10].

10. Temperature probes and clamp thermometers

Clamp thermometers and probes measure line temperatures for superheat and subcooling, and air temperatures over coils. Check the range, the accuracy and that the clamp fits your pipe sizes. Insulate the probe from the surrounding air.

11. Gas detectors and a personal CO2 detector

A gas detector monitors the air you work in. For A2L, Chemours lists one certified for 2L and says to test the oxygen level before entering an enclosed area, because a leak detector does not show oxygen ^[1]. CO2 is odourless, heavier than air and collects near the floor ^[2]. Danfoss recommends a personal R744 detector ^[3].

12. Personal protective equipment

• Eyes: goggles and a face shield where liquid can escape ^[1].
• Hands and skin: gloves and long sleeves against frostbite ^[1]; anti-freeze gloves on CO2 ^[3].
• Hearing and head: ear protection, and a helmet where needed, on CO2 ^[3].
• Breathing: canister masks are for escape only; high vapour levels need self-contained breathing apparatus ^[1].
• Ventilation: a fan rated for A2L where ventilation is poor ^[1].

Checklist

• Gauges, hoses and regulator rated for the PS of the system.
• Micron gauge on the system; vacuum pump suitable for the refrigerant.
• Leak detector to EN 14624, certified for 2L, or intended for A3 or CO2.
• Recovery machine approved for the refrigerant; A2L cylinders labelled, left-hand thread.
• Two-pole voltage tester, proving unit, correct CAT rating.
• Gas detector or personal CO2 detector working; PPE on.