HVAC Toolkit

Refrigerant Retrofit Guide

R-22 phase-out and replacement options for HVAC systems

R-22 (HCFC-22) Phase-Out

R-22 production and import has been banned in most countries due to its ozone depleting potential (ODP = 0.055).

  • • USA: Production/import banned January 1, 2020
  • • EU: Banned since January 1, 2015
  • • Most other countries: Phased out by 2030 (Montreal Protocol)

Only recycled or reclaimed R-22 is available, with prices increasing. Consider retrofit or system replacement.

R-22 Replacement Options

Property R-22
(Original)		 R-407C
(Drop-in)		 R-410A
(New system)		 R-32
(Low GWP)		 R-454B
(Ultra-low GWP)
GWP 1,810 1,774 2,088 675 466
ODP 0.055 0 0 0 0
Safety Class A1 A1 A1 A2L A2L
Operating Pressure 1.0x ~1.0x ~1.6x ~1.6x ~1.4x
Compressor Oil MO / AB POE POE POE / PVE POE
R-22 System Compatible? - Yes* No No Limited
Capacity vs R-22 100% 95-100% 100%+ 100%+ 95-100%
Temperature Glide 0°C 4-7°C 0.1°C 0°C 1.3°C

* R-407C is compatible with R-22 systems after oil change to POE and component verification

1

R-407C Retrofit Procedure

Best "drop-in" option for existing R-22 systems

  1. 1 Recover all R-22 from the system (required by law)
  2. 2 Drain and replace oil - Change to POE oil (e.g., 3GS or 4GS viscosity)
  3. 3 Replace filter-drier - Use one compatible with POE oil
  4. 4 Replace or verify TXV - May need R-407C specific valve
  5. 5 Check gaskets/seals - Replace any incompatible materials
  6. 6 Evacuate system - 500 microns minimum
  7. 7 Charge R-407C as liquid - Never charge as vapor (fractionation)
  8. 8 Adjust settings - May need to adjust superheat (use dew point)
  9. 9 Label system - Update refrigerant type on all labels

Charge amount: Start with ~90-95% of R-22 charge. Adjust based on subcooling (use bubble point for measurement).

2

R-410A System Replacement

Complete system replacement (not retrofit)

Warning: R-410A operates at 60% higher pressure than R-22. Never charge R-410A into an R-22 system - components will fail.

When to choose R-410A replacement:

  • ✓ System is >15 years old
  • ✓ Compressor failure or major leak
  • ✓ Poor efficiency (SEER <10)
  • ✓ Need capacity increase
  • ✓ R-22 price makes repair uneconomical

What must be replaced:

  • • Condensing unit (complete)
  • • Evaporator coil
  • • TXV/metering device
  • • Filter-drier
  • • Lineset (if not rated for 600+ psi)
  • • Disconnect and wiring (may need upsizing)

Consider R-32 or R-454B: For new installations, these low-GWP options may be required by new regulations and offer better efficiency.

Understanding Temperature Glide

R-407C is a zeotropic blend with significant temperature glide (4-7°C). This means the refrigerant evaporates and condenses over a temperature range, not at a single point.

Critical Measurement Points

  • • Superheat: Use dew point (higher temp) from P-T chart
  • • Subcooling: Use bubble point (lower temp) from P-T chart
  • • Charging: Always charge as liquid to prevent fractionation

Example: R-407C at 150 psig

Bubble Point (liquid): 33°C (91°F)
Dew Point (vapor): 38°C (100°F)
Temperature Glide: 5°C (9°F)

For subcooling: If liquid line is 29°C at 150 psig → Subcooling = 33 - 29 = 4°C

Other Retrofit Refrigerants

Refrigerant Trade Names Type Pros Cons
R-407C SUVA 407C, Genetron 407C HFC Zeotropic Most common, similar pressure Oil change required, temp glide
R-422D ISCEON MO29 HFC Zeotropic Works with MO or POE oil Lower efficiency, high GWP
R-427A Forane 427A HFC Zeotropic Better glide than R-407C Less available, POE required
R-438A ISCEON MO99 HFC Zeotropic Closer to R-22 performance Higher pressure than R-22
R-290 Propane Natural (HC) GWP=3, excellent efficiency Flammable (A3), charge limits

Important: Always consult equipment manufacturer guidelines before any retrofit. Some systems may not be approved for certain refrigerants. Warranty implications should be considered.

Quick Decision Guide

System Age <10 years

Good condition, minor service

→ Retrofit to R-407C

Cost effective, extends system life

System Age 10-15 years

Fair condition, major repair needed

→ Consider replacement

Compare retrofit cost vs new system ROI

System Age >15 years

Compressor failure or poor efficiency

→ Replace system

New R-32 or R-454B for best efficiency