Buying a house with an old AC unit or R-22 system

Is it a problem to buy a house with an old AC unit?

If you're buying a house with an old AC unit, treat it as a cost to price before your deadline, not a reason on its own to walk away. The unit can keep running, and the Environmental Protection Agency (EPA) says there is "no EPA requirement to get a new system" just because it runs on R-22. The catch is money: R-22 is no longer made or imported in the U.S., so it is scarce and expensive. Get a licensed HVAC technician's written bid on both repair and replacement, then ask the seller for the replacement number if the unit is near the end.

Key takeaways

• The International Association of Certified Home Inspectors (InterNACHI) puts a central AC's life at 7 to 15 years. Any R-22 unit was made before 2010, so it is past that range.
• R-22 refrigerant alone runs $90 to $250 a pound, so price the replacement before you accept a recharge credit.
• Carrier's age-times-repair-cost rule tips a 15-year-old unit toward replacement once a repair tops about $333.

How old is too old for an AC unit?

InterNACHI lists 7 to 15 years for a central air conditioner and 8 to 20 years for the outdoor condenser. Past that range, plan for replacement.

R-22 is a marker for age. Trane says the last R-22 units were made in 2009 or earlier, so an R-22 unit is at least 17 years old in 2026. To confirm which refrigerant you have, look at the nameplate. EPA notes that most units have one that "identifies the refrigerant it contains." Ask the technician to confirm the age from the same plate.

Can you still get R-22, and can you keep using it?

Yes to both, with limits. EPA's phaseout fact sheet says production and import ended on January 1, 2020, "but you may continue to use HCFC-22 in your existing system for as long as necessary." What's left is reclaimed refrigerant and stock made before 2020.

You can't buy it yourself. Trane says only an HVAC company can, and it's getting harder to find.

A unit that needs refrigerant usually has a leak. Ask the technician to find it before you price a recharge, because a recharge alone is a temporary fix.

Never let anyone top up an R-22 system with R-22a or propane. EPA calls R-22a "highly flammable and not an acceptable alternative for your residential AC system," and says propane and other unapproved refrigerants pose "a fire or explosion hazard".

What does it cost to recharge or replace an R-22 system?

The figures below differ mostly by scope. A recharge buys refrigerant for an old unit. A replacement buys a new system.

Trane's figure leaves out the service call and any other parts or repairs, and UniColorado says a leaking system will likely need another recharge within 1 to 2 years. HomeAdvisor also tells you to budget for ductwork, electrical panel upgrades and drain line work, depending on the house. The HVAC contractor's written bid replaces every figure here. Kept prices every line of an inspection report for $79, usually under 4 hours, and marks the ones that need a professional quote.

Should you repair or replace an old R-22 unit?

Carrier's rule of thumb: multiply the unit's age by the repair cost. If the result exceeds $5,000, replacement is generally more cost-effective. Carrier calls it a rule of thumb, not a substitute for a professional evaluation.

Here is how it plays out on an R-22 unit. Trane says a full recharge may need 2 to 4 pounds per ton. Take a 3-ton system:

• Refrigerant: 3 tons x 2 to 4 pounds = 6 to 12 pounds.
• At Trane's $150 average per pound: $900 to $1,800, before the service call and any other parts.
• Carrier's rule: 17 years x $900 = $15,300, three times the line.

At 15 years old, the line is $5,000 ÷ 15, or about $333. HomeAdvisor puts a common AC repair at around $400, and every recharge figure above costs more, so get the replacement bid first.

Who can tell you if the AC needs replacing before your deadline?

A licensed HVAC technician who runs the system, reads the nameplate and checks for leaks. EPA says to use dealers whose technicians are EPA-certified to handle refrigerants, often called Section 608 certification. Ask for a written bid on the repair and on a full replacement, sized for the house.

For how to get a bid inside your window, see how to get repair estimates during the inspection period.

What should you ask the seller for?

Ask for the replacement at the contractor's bid, as a credit, a price reduction or the work itself. Name the scope and the trade, such as replacing the R-22 system by a licensed HVAC contractor, and attach the written bid so the figure has a source.

Don't settle for a recharge-only credit unless the leak is found and priced too. If the unit cools and the technician finds no leak, you can ask for a partial credit instead. What to ask for after a home inspection shows how this fits your list, and the buyer repair request letter template gives the wording. If the seller does the work, ask for the contractor's invoice, and the permit if your town requires one, before closing.

If the seller says no, an old AC is a known cost, not an unknown one. Weigh the bid against your budget, and see when to walk away after a home inspection. Your contract sets the deadline and terms, so confirm them with your agent or attorney.

What is a good replacement for R-22 refrigerant?

In an existing unit, usually more R-22. EPA allows conversions to approved substitutes, but says they "will not work well without making changes to system components," so technicians who fix a leak most often recharge with R-22. New systems start with a different refrigerant. Trane says new units are designed for R-454B, and R-410A, the first R-22 replacement, is being phased out too.

How long will R-22 be available?

EPA sets no end date for using it in an existing system. Your technician's per-pound price today is the best guide to what the next recharge will cost.

How much does it cost to replace the AC in a 2,000 square foot house?

HomeAdvisor sizes a 2,000 to 2,500 square foot home at 40,000 to 50,000 BTUs. A 4-ton (48,000 BTU) unit falls in that range, and HomeAdvisor prices it at $2,600 to $6,200. Installation labor adds $300 to $1,600, for $2,900 to $7,800 before ductwork, electrical or drain work. A contractor's load calculation sets the real size.

The AC is one line on your report. Upload your inspection report to Kept and get a priced memo for the rest, so your HVAC bid is the only number you still need to chase.

Sources

• EPA, Residential Air Conditioning and the Phaseout of HCFC-22: What You Need to Know
• EPA, Purchasing and Repairing Home Air-Conditioners or Heat Pumps
• InterNACHI, Standard Estimated Life Expectancy Chart for Homes
• Trane, Is R-22 Refrigerant Available, and What Does R-22 Cost?
• Carrier, HVAC Replacement Cost Guide
• HomeAdvisor, How Much Does an AC Unit Cost?
• UniColorado, When Was R22 Phased Out? Is It Still Available?
• Denommee Plumbing, AC Recharge Cost vs. Replacement Guide