MO99 refrigerant, also called R-438A, typically costs about $20-$40 per pound when priced from a refrigerant cylinder, while an HVAC contractor may charge $75-$150 per pound for refrigerant added during a service visit. Cylinder size, supplier, location, leak diagnosis, and service labor can change the final bill.
For a residential recharge, the refrigerant itself is often only part of the total service cost. The ranges below are estimates; MO99 is generally handled by trained, appropriately certified HVAC technicians.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| MO99 in a 25-lb cylinder | $500 | $750 | $1,000 | About $20-$40 per lb; supplier and availability vary |
| Contractor refrigerant charge | $75 per lb | $110 per lb | $150 per lb | May include handling or service markup |
| Residential service visit | $150 | $350 | $700 | Depends on refrigerant quantity and diagnostic work |
| Leak repair plus recharge | $300 | $800 | $1,800+ | Repair complexity and system size drive the total |
What a pound of MO99 costs in a service quote
For the refrigerant alone, a reasonable planning range is $20-$40 per lb when comparing cylinder prices. A contractor’s billed rate is commonly higher, around $75-$150 per lb, because it can include sourcing, transport, recovery equipment, handling, and business overhead. Some companies quote a flat recharge or diagnostic package instead of itemizing pounds.
Many residential systems take several pounds, but the required amount depends on the equipment and the leak or service condition. A recharge should follow the equipment manufacturer’s specifications; adding refrigerant without diagnosing a leak can lead to repeat expense and poor performance.
Assumptions: U.S. pricing, standard residential service access, and ordinary supplier availability. Local labor rates and contractor pricing vary.
How cylinder size, labor, and diagnostics shape the bill
A cylinder purchase and a completed HVAC service are different price comparisons. A full cylinder may contain 25 lb, while a service call uses only the amount the system needs. Contractors also account for labor, diagnostic time, recovery or evacuation tasks, and any repair materials.
| Quote component | Typical range | Pricing basis | What it may cover |
|---|---|---|---|
| MO99 refrigerant | $20-$40 per lb wholesale/retail cylinder equivalent | Per pound | Refrigerant supply |
| Contractor refrigerant | $75-$150 per lb | Per pound billed | Product, handling, and markup |
| Diagnostic or visit fee | $75-$200 | Per visit | System checks and troubleshooting |
| HVAC labor | $90-$175 per hour | Per hour | Testing, charging, and service work |
| Leak repair parts | $25-$500+ | Per repair | Small fittings through difficult component repairs |
Ask whether the quote separates refrigerant pounds, labor, diagnostic fees, and leak repair. That breakdown makes competing estimates easier to compare.
Why system capacity and leak size change MO99 quantities
The equipment nameplate and service measurements determine the correct charge, not a universal pounds-per-home rule. A small residential system may need only a few pounds added; larger equipment or a system with a substantial loss can require more. The contractor should explain the measured quantity and the manufacturer’s charging procedure.
Leak size also changes the work. A readily accessible fitting may be a modest repair, while a leak in an indoor coil or a concealed line set can require several labor hours and more extensive testing. If a system has lost most of its charge, the technician may need to locate and repair the leak before recharging it.
MO99 is not a substitute for checking compatibility and charge requirements. Conversion from another refrigerant can require equipment-specific procedures and adjustments; the system’s label and technician’s assessment matter.
When MO99 conversion adds work beyond the refrigerant
MO99 is used in some existing systems designed for R-22, but converting a system is not necessarily a simple top-off. The contractor may need to recover the existing refrigerant, inspect the equipment, replace components or seals where appropriate, evacuate the system, and charge it according to the manufacturer’s guidance.
A straightforward service may total roughly $250-$600 when only a small quantity is needed and no significant repair is required. A conversion with recovery, testing, and additional parts can reach $500-$1,500 or more. These are broad job estimates, not a fixed conversion fee; equipment condition and the scope of work determine the price.
What a leak repair and MO99 recharge can total
Three illustrative quotes show how quantity and access affect the expense. A minor fitting repair using 2 lb at $100 per lb, plus a $125 visit and about $150 in labor or parts, comes to approximately $475. A moderate repair using 4 lb, with a $150 diagnostic charge and $400-$700 in repair labor and parts, may total around $850-$1,250.
A difficult coil or concealed-line repair using 6 lb at $125 per lb, plus several hours of labor and parts, could reach $1,500-$3,000. These examples assume no equipment replacement and vary by region and contractor. Get the refrigerant quantity and repair scope in writing before authorizing a recharge.
Regional MO99 rates and contractor access
Rates tend to be higher in major metropolitan areas and places with high labor costs. A practical estimate is that urban-market service pricing may run 10%-25% above a lower-cost rural market, while remote locations can also cost more when travel or limited contractor availability applies. Cylinder pricing can differ by supplier and shipping charges.
During peak cooling season, urgent appointments may carry a higher visit or after-hours fee, often adding $50-$200 or more. Ask whether the estimate includes travel, emergency service, and refrigerant delivery instead of assuming the per-pound line is the full charge.
How to lower the MO99 recharge price without repeat work
Compare two or three written estimates that state the diagnostic fee, price per pound, expected quantity, labor rate, and leak-repair scope. Confirm whether unused refrigerant is credited and whether the quote includes recovery, evacuation, and performance testing where needed. Avoid choosing solely by the lowest per-pound rate if the leak diagnosis is excluded.
Scheduling during normal business hours, improving access to the indoor and outdoor equipment, and sharing the system model and service history can reduce avoidable time or rush charges. If the system repeatedly needs refrigerant, compare the cost of a lasting leak repair with continued recharges. Fixing the leak can cost less over time than paying for repeated MO99 additions.
Buying MO99 by the pound versus paying a technician
Retail cylinder pricing is not the same as the price a homeowner can usually obtain or the cost of a lawful service. U.S. refrigerant sales and handling are subject to federal rules; many buyers need EPA Section 608 certification to purchase regulated refrigerant, and technicians must follow applicable recovery and handling requirements. A homeowner should verify current rules rather than assume a cylinder can be bought and charged independently.
For budgeting, use $20-$40 per lb as a cylinder-equivalent product range and $75-$150 per lb as a contractor-billed refrigerant range, then add the visit, diagnosis, and any repair. The final written quote should identify MO99/R-438A specifically and explain whether the rate covers refrigerant only or a complete service.