Your air conditioner and heat pump run on HVAC refrigerant in the same way a car runs on fuel, except that refrigerant is not consumed. It circulates in a closed loop, transferring heat from inside the home to outside, and returns to start the cycle again. A system with the right HVAC refrigerant at the correct charge level operates efficiently and reliably. A system with a leak, the wrong type, or an incorrect charge level works harder than it should, cools less effectively than it should, and risks compressor damage that can end the life of the equipment prematurely.
Most homeowners never think about HVAC refrigerant until something goes wrong. Understanding the basics- what it does, which types exist, and what the current regulatory environment looks like- helps demystify service calls and supports better decisions when a technician recommends an HVAC refrigerant-related repair or system replacement.
How HVAC Refrigerant Works
HVAC refrigerant transfers heat by cycling between liquid and gas states through a continuous loop. The cycle has four stages, each involving a different component of the system.
| Stage | Component | What Happens |
| 1 | Evaporator coil | HVAC refrigerant absorbs heat from indoor air, evaporating from liquid to gas |
| 2 | Compressor | Gas is compressed, raising its pressure and temperature |
| 3 | Condenser coil | Hot gas releases heat to outdoor air, condensing back to liquid |
| 4 | Expansion valve | Liquid HVAC refrigerant expands and cools, returning to the evaporator |
The key physical principle is that refrigerants have very low boiling points. At the pressure present in the evaporator coil, the HVAC refrigerant boils and absorbs a large amount of heat from the surrounding air in the process. This is what makes HVAC refrigerant so much more efficient than generating heat or cooling through other means. At the higher pressure present in the condenser coil, it condenses and releases that heat outside. No heat is generated. It is moved from one location to another, which is why the process is far more energy-efficient than generating heat through combustion or electric resistance.
Types of HVAC Refrigerant: A Comparison
The type of HVAC refrigerant in a system is determined at the factory and cannot be changed without replacing system components. Each refrigerant has a specific pressure profile, lubrication requirement, and compatibility with seals and components that make mixing or substituting them damaging to the system.
| Type | Common Name | Ozone Impact | GWP | Status |
| R-22 | Freon | High (HCFC) | 1,810 | Phased out, no new production since 2020 |
| R-410A | Puron | None (HFC) | 2,088 | Being phased down under AIM Act, still in many systems |
| R-32 | None common | None (HFC) | 675 | Growing use in newer equipment |
| R-454B | Puron Advance | None (HFO blend) | 466 | Replacing R-410A in new systems from 2025 |
| R-290 | Propane | None (natural) | 3 | Used in small commercial and some residential units |
R-22: The Phase-Out You Need to Know About
R-22, marketed as Freon, was the standard HVAC refrigerant in residential air conditioning for decades. The EPA phased out production and import of R-22 in 2020 under the Clean Air Act because it is a hydrochlorofluorocarbon that depletes the stratospheric ozone layer. You can review the full EPA refrigerant phase-out details at the EPA refrigerant management resource page. Since the phase-out, the only R-22 available is recovered and recycled from existing systems or imported from approved sources under strict regulations. Supply has shrunk steadily, and prices have increased dramatically as a result.
The practical implication for homeowners is straightforward. If your air conditioner or heat pump uses R-22 HVAC refrigerant and it develops a refrigerant leak, you face a choice between paying increasingly expensive R-22 prices to recharge the system, which does not fix the underlying leak, or replacing the system with current-refrigerant equipment. Any R-22 system that is already 10 or more years old and developing a leak is almost always a stronger candidate for replacement than for repeated R-22 recharges. The refrigerant cost premium on older equipment compounds with the efficiency gap between aging systems and modern replacements.
R-410A and the Next Transition
R-410A replaced R-22 as the dominant residential HVAC refrigerant and is still present in most operating central air conditioning systems and heat pumps manufactured before 2025. It does not deplete the ozone layer, but it carries a Global Warming Potential of 2,088, meaning it is 2,088 times more potent as a greenhouse gas than carbon dioxide on a weight basis. This high GWP has driven regulatory action to phase it down under the AIM Act, which required equipment manufacturers to transition to lower-GWP alternatives beginning in January 2025.
R-410A systems will continue to be serviced with R-410A HVAC refrigerant throughout their operational lives. The regulatory change affects new equipment manufacturing, not existing systems. Homeowners with R-410A systems do not need to do anything different in terms of HVAC refrigerant management. However, when the time comes to replace aging R-410A equipment, the replacement will use a different refrigerant, typically R-454B or R-32, which carry significantly lower GWP values. This transition is worth understanding when evaluating the long-term outlook for a system that is approaching the end of its service life.
What Happens When Refrigerant Leaks
HVAC refrigerant circulates in a closed loop and is not consumed during normal operation. A properly functioning system that was correctly charged at installation does not need refrigerant added over time. When a system is consistently low on HVAC refrigerant, it means there is a leak somewhere in the system. Adding HVAC refrigerant without finding and repairing the leak is a temporary measure that addresses the symptom without addressing the cause.
The consequences of operating on a low HVAC refrigerant charge extend beyond reduced cooling performance. When refrigerant levels are low, the compressor works under conditions that are outside its designed operating parameters. Suction pressure drops, discharge temperatures rise, and the oil that lubricates the compressor may not circulate properly. Sustained operation with a low HVAC refrigerant charge is one of the leading causes of premature compressor failure, which is the most expensive single repair in a central air conditioning system. Finding and repairing the leak before recharging is not just the environmentally correct approach to HVAC refrigerant management. It is the approach that protects the equipment and prevents the compressor damage that a chronically low HVAC refrigerant charge causes over time.
HVAC Refrigerant and System Efficiency
The HVAC refrigerant charge level has a direct and measurable impact on system efficiency. An overcharged or undercharged system operates less efficiently than one at the correct level, consuming more electricity to deliver the same cooling output. This efficiency loss shows up as higher energy bills without any obvious symptom other than a system that seems to run more than expected. A technician measuring the system’s operating pressures and superheat and subcooling values during a tune-up can identify charge level issues before they produce more visible symptoms.
The type of HVAC refrigerant also affects efficiency. Newer low-GWP refrigerants like R-454B and R-32 are designed to deliver equivalent or better efficiency than R-410A at lower charge levels, which reduces both the environmental impact per unit of cooling produced and the potential leak exposure if the system develops a leak. These efficiency and environmental improvements are part of why the regulatory transition to lower-GWP HVAC refrigerant types is happening alongside advances in equipment design rather than in isolation.
What Homeowners Can and Cannot Do
HVAC refrigerant handling is federally regulated. Purchasing refrigerants with a GWP above 150 in quantities intended for HVAC use requires EPA Section 608 certification. This applies to all common residential refrigerants including R-22, R-410A, R-454B, and R-32. Homeowners cannot legally purchase or add HVAC refrigerant to their systems without this certification. Any service involving refrigerant must be performed by a certified technician using approved equipment for leak detection, recovery, and charging.
What homeowners can and should do is recognize the symptoms of a low HVAC refrigerant charge and contact a qualified technician promptly when they appear. These symptoms include a system that runs continuously without reaching the thermostat set point, ice forming on the refrigerant lines or evaporator coil, a notable reduction in cooling capacity compared to previous seasons, and hissing or bubbling sounds near the refrigerant lines or outdoor unit. None of these symptoms should be ignored or attributed to hot weather, because the underlying condition degrades the system progressively if not addressed.
Schedule an HVAC Refrigerant Check With Aspen One Hour
If you suspect a refrigerant issue with your air conditioner or heat pump, or if your system has not been professionally serviced recently, the team at Aspen One Hour Heating and Cooling can diagnose the issue accurately, repair any leaks, and restore the correct HVAC refrigerant charge. Contact Aspen One Hour Heating and Cooling today to schedule your service visit.
Frequently Asked Questions
What is HVAC refrigerant and why does it matter?
HVAC refrigerant is the substance that circulates through your air conditioning or heat pump system to transfer heat from inside the home to outside. It makes cooling possible by absorbing heat at the evaporator coil indoors and releasing it at the condenser coil outdoors. Without the correct HVAC refrigerant at the correct charge level, an air conditioning or heat pump system cannot cool effectively. Low refrigerant reduces cooling capacity, increases compressor stress, and can lead to premature equipment failure.
How do I know if my AC is low on refrigerant?
The most common signs of a low HVAC refrigerant charge are an air conditioner that runs nearly continuously without reaching the thermostat set point, ice forming on the refrigerant lines or evaporator coil, a noticeable reduction in cooling effectiveness compared to previous seasons, and hissing or bubbling sounds near the outdoor unit or refrigerant lines. Any of these symptoms warrants a service call from a certified technician who can measure the system’s actual charge level and determine whether a leak is present.
What refrigerant does my AC use?
The type of HVAC refrigerant a system uses is stamped on the equipment nameplate, typically located on the outdoor condenser unit. Most residential systems manufactured before 2010 use R-22. Systems manufactured between roughly 2010 and 2024 most commonly use R-410A. Systems manufactured from 2025 onward are required to use lower-GWP alternatives, with R-454B being the most common replacement for R-410A in new residential equipment. Using a different refrigerant than what the system was designed for damages components and voids equipment warranties.
Can HVAC refrigerant be added without fixing a leak?
Technically yes, but it is not a responsible or effective long-term solution. Adding HVAC refrigerant to a leaking system without repairing the leak means the refrigerant will continue to escape, requiring repeated recharges while the underlying leak worsens. EPA regulations also require that refrigerant leaks above certain thresholds be repaired rather than simply topped off. The correct approach is to leak-test the system, identify and repair the leak, and then recharge to the manufacturer-specified level.
Why is R-22 refrigerant so expensive now?
R-22 HVAC refrigerant production and import were banned in the United States as of 2020 under the EPA’s Clean Air Act phase-out of ozone-depleting substances. Since that date, the only R-22 available has come from recovered and recycled stocks, which are finite and diminishing. As supply decreases and existing R-22 systems continue to require service, prices have risen significantly and will continue to do so. Homeowners with R-22 systems facing significant leaks are typically better served by replacing the system with current-refrigerant equipment than by paying premium prices for R-22 recharges on aging hardware.
What refrigerant will new air conditioners use after 2025?
New residential central air conditioners and heat pumps manufactured after January 1, 2025 are required by federal regulation to use HVAC refrigerant with a Global Warming Potential of 750 or below. R-454B, sold under the trade name Puron Advance, is the most common replacement for R-410A in residential split systems. R-32 is also used in some configurations. Both carry significantly lower GWP values than R-410A at 466 and 675 respectively, compared to R-410A’s 2,088. These refrigerants are mildly flammable, classified as A2L, which requires updated equipment design and installation practices but does not present meaningful safety concerns in properly installed residential systems.
Aspen One Hour Heating and Cooling proudly serves Jackson, Michigan and the surrounding communities including Lansing, Ann Arbor, Battle Creek, and the greater mid-Michigan area. Questions about HVAC refrigerant, AC service, or system replacement? Contact our team today.
