Can you recharge a window AC unit? What federal refrigerant rules mean for window units

Why a window unit is a sealed small appliance

Federal refrigerant rules sort equipment into groups, and a window unit falls in the group called small appliances. The rule defines a small appliance as one fully manufactured, charged and hermetically sealed in a factory with five pounds or less of refrigerant.

The same definition names room air conditioners, including window units and portable units.

The rules bar selling, distributing, or offering for sale or distribution a small appliance without a process stub to make removing refrigerant easier at servicing and disposal, unless it contains only exempt refrigerants.

The rule defines a process stub as "a length of tubing that provides access to the refrigerant inside a small appliance or room air conditioner and that can be resealed at the conclusion of repair or service."

The rules exempt some refrigerants in some uses, including propane (R-290) and R-441A in self-contained room air conditioners for residential and light commercial air-conditioning. Those exemptions cover the rules' ban on knowingly venting refrigerant and their other requirements (40 CFR Part 82, Subpart F).

What the federal rules say about recharging

On its page for homeowners, the EPA answers the question "May I purchase my own refrigerant to recharge my appliance?" It says: "Section 608 Certification is required to recharge appliances." Section 608 refers to a portion of the federal Clean Air Act.

One part of the federal rule's definition of a technician covers any person who, in the course of maintenance, service or repair of an appliance (except motor vehicle air conditioners), could be reasonably expected to violate the integrity of the refrigerant circuit and therefore release refrigerants into the environment. The rule's examples include attaching hoses and gauges, and adding or removing refrigerant.

For appliances with a refrigerant that is not exempt, the certification rule says people whose maintenance, service or repair of small appliances could be reasonably expected to violate the integrity of the refrigerant circuit must be certified as Type I technicians. Universal certification covers all equipment types, including small appliances. The EPA says these credentials do not expire. It also says apprentices are exempt if a certified technician closely and continually supervises them.

Low refrigerant: fix the leak first

The Department of Energy's home cooling guide puts it plainly for a unit that is not cooling: "Your refrigerant could be low or leaking. Call a trained technician to repair the leak and recharge the system."

The EPA says to ask your service technician to locate and repair the leak instead of topping it off. The EPA adds that major leaks rarely develop in properly installed and regularly maintained units. For how leaks are found and fixed on central systems, see our guide to refrigerant leak repair.

Before you assume refrigerant is the problem, two things are yours to check. The Department of Energy says a clogged filter restricts airflow and cuts the unit's ability to cool. It also says to check that the thermostat is set properly. Our window AC repair guide covers the other owner checks.

Some window units use a flammable refrigerant

The Midea window unit manual states that a flammable refrigerant called R32 is used within the appliance. R32 is a refrigerant that can catch fire, and the manual says no open fire or spark-making device should be around the unit.

The manual says servicing shall only be performed as recommended by the manufacturer. It tells owners to contact the authorized service technician for repair or maintenance. It says anyone working on or breaking into a refrigerant circuit should hold a current valid certificate from an industry-accredited assessment authority that authorizes their competence to handle refrigerants safely.

The manual also warns that the refrigerant may not have an odor.

The EPA says the refrigerant in a home air conditioner is typically listed on the unit's nameplate. If there is no nameplate, it says to check the owner's manual.

Repair, replace or recycle the unit

A Department of Energy infographic lists a life span of 10 to 15 years for a room air conditioner. The EPA recommends a professional evaluation when equipment is more than 10 years old or is not keeping your home comfortable. In practice, on an older window unit, ask whether a leak repair is worth doing before anyone adds refrigerant.

The EPA says not to tamper with an appliance before it is disposed of, such as cutting refrigerant lines or removing compressors. A compressor is the pump that moves refrigerant through the unit.

The EPA says the final disposer of appliances is responsible for recovering any refrigerant they contain. It also says: "Persons recovering refrigerant from small appliances (i.e., appliances containing five pounds or less of refrigerant) in the waste stream are not required to be Clean Air Act section 608 certified." The EPA suggests checking first with your electric utility for an appliance turn-in program.

The EPA also suggests checking with your local government. It says some localities may require the refrigerant to be recovered before they will pick an appliance up. The EPA warns that appliances left curbside might be landfilled or otherwise disposed of in an unsafe manner. If you are choosing a new unit, our guide to window air conditioner types covers the options.

Questions to ask, and a note on Florida

The rules quoted on this page are federal. We did not check for a Florida rule specific to window units.

The EPA says you can ask a service technician to show you a certification card. These questions are fair to ask anyone offering to add refrigerant to a window unit:

1. Does the technician doing the work hold Section 608 Type I or Universal certification?
2. Where is the leak, and will it be repaired before refrigerant goes in?
3. Is the technician trained on the refrigerant listed on the nameplate, such as R32?
4. Given the unit's age, is a repair worth it, or is replacement the better choice?
5. If the unit is replaced, who recovers the refrigerant from the old one?

For the wider set of refrigerant rules, see our guide to EPA Section 608 refrigerant rules.