Freon™ MO99 (R-438A) Refrigerant 25 lb Jug — Top-Off Approved R-22 Replacement
Freon™ MO99 (R-438A) is the closest match to R-22 of all the "no oil change" replacement refrigerants. It matches R-22's capacity and efficiency in most systems but runs a significantly lower discharge temperature, which may extend compressor life. It's compatible with both mineral oil and POE oil, and unlike many R-22 replacements, it can be topped off during service without removing the entire charge. This made-in-USA 25 lb jug gives contractors a fast, cost-effective way to keep R-22 air conditioning equipment running. Purchase requires EPA Section 608 certification.
Is MO99 the Right R-22 Replacement?
MO99 is for contractors who want an R-22 conversion with as little disruption as possible: no oil change, R-22-like capacity, and the ability to top off later. That makes it especially practical for older systems that may need service again before they're replaced.
For most R-22 systems, the retrofit is simple: recover the R-22, replace critical seals, charge with MO99, restart and monitor for leaks, then label the system with an MO99 retrofit label.
Ideal for: Converting R-22 air conditioners and heat pumps to a replacement refrigerant without changing the oil.
Need a full changeover option? Compare NU-22B (R-422B) and R-407C.
Refrigerant purchases require the Refrigerant Agreement and proof of EPA Section 608 certification. Performance varies by system; follow the equipment manufacturer's retrofit guidelines. For use by qualified HVAC/R technicians. Request free sizing assistance, contact Budget Heating, or call 813-885-7999.
What's Included
| Refrigerant | Freon™ MO99 (R-438A) |
|---|---|
| Net Weight | 25 lb |
| Replaces | R-22 |
| Lubricant Compatibility | Mineral oil and POE |
| Top-Off | Can be topped off without removing the entire charge |
| Discharge Temperature | Significantly lower than R-22 |
| Country of Origin | Made in USA |
| Purchase Requirement | EPA Section 608 certification |
A 25 lb supply of MO99 for no-oil-change R-22 retrofits that can be topped off on later visits.
Refrigerant & Retrofit Features
Freon™ MO99 (R-438A)
- Closest match to R-22 of the "no oil change" replacements
- Matches R-22 capacity and efficiency in most systems
- Significantly lower discharge temperature
- May extend compressor life
- Compatible with mineral oil
- Compatible with POE oil
- Compatible with traditional and new lubricants
- Top-off approved
- Made in USA
- 25 lb jug
Retrofit Steps
- Recover the R-22 charge
- Replace critical seals
- Charge the system with MO99
- Restart the system
- Monitor for leaks
- Label with an MO99 retrofit label
- No oil change required
- Top off later without full recovery
- Use certified recovery equipment
- For qualified HVAC/R technicians
Frequently Asked Questions
Can MO99 be topped off later?
Yes. MO99 can be topped off during service without removing the entire refrigerant charge.
Do I have to switch the oil from mineral oil to POE?
No. MO99 is compatible with both mineral oil and POE, so an oil change isn't required for the retrofit.
What's involved in converting an R-22 system to MO99?
For most systems: recover the R-22, replace critical seals, charge with MO99, restart, monitor for leaks, and label the system with an MO99 retrofit label.
How does MO99 compare with R-22 in performance?
MO99 matches R-22 capacity and efficiency in most systems, with a significantly lower discharge temperature that may help the compressor last longer.
What's the ASHRAE number for MO99?
Freon™ MO99 is ASHRAE R-438A.
What should I recover the old R-22 into?
Use certified recovery equipment and a cylinder such as the 30 lb refrigerant recovery cylinder, rated for CFC, HCFC, and HFC refrigerants.
