You can thank your air conditioner for having a cool, comfortable home during the hottest days of the year. More specifically, you can thank your AC refrigerant. Refrigerant is the key component of your HVAC system. Without refrigerant your AC would not have the ability to extract heat and remove it using the power of evaporative heat transfer.
It’s helpful to know a little bit about AC refrigerant in case you ever need to have it refilled or there’s a maintenance problem in which it involves.
What is AC Refrigerant?
Refrigerant is a chemical compound capable of transforming from a liquid to a gas, and vice versa. This basic principle is what allows warm air from your home to be pulled into the AC system and replaced with cool air. When heat passes over coils containing liquid refrigerant, the air cools while the heat gets absorbed into the liquid refrigerant. This causes the liquid refrigerant to evaporate and expand into a gas. This gas is compressed and moved outside where the heat can be dissipated before the refrigerant repeats the process on a continuous loop. The air that is cooled is then returned to the space it was drawn from at a temperature that is comfortable.
Air conditioning refrigerants have come in many different chemical combinations over the years with several being banned due to the environmental impact they had. The most commonly known refrigerants include:
- R-12
- R-22
- R-134
- AR-410
- AFreon®
- Puron®
What Does Refrigerant Do?
While there are many different types of refrigerants, they all serve the same purpose: cooling the air in your home. This is achieved using the evaporative process. The primary function of refrigerant is to act as a vehicle that traps and releases heat depending on what phase change occurs.
Liquids evaporate when exposed to heat which occurs when liquid refrigerants pass through the interior coils of an AC unit. This cooled refrigerant is warmed by the ambient air inside of a space. The cool coils prompt heat transfer as the air surrounding the coils is cooled and the refrigerant inside the coils starts to warm. The warming refrigerant starts to expand into its gaseous form before being passed into the compressor. Warm gasses under pressure heat up which then causes the pressurized and heated refrigerant to move to the outside condenser unit of an AC system. The pressurized and heated refrigerant is rapidly cooled by being blown through the condenser coils, which causes another phase change that changes the refrigerant back into a liquid state. Once the refrigerant completes the phase change cycle it moves back through the system to extract more heat until a desired temperature is reached, and the AC unit turns off.
How Refrigerant Has Changed
The first refrigerant was developed in 1928 by Thomas Midgley, Albert Henne, and Robert McNary, who were researchers at General Motors in the air conditioning division.
Other types of refrigerants had existed, like Sulphur Dioxide and Ammonia, but they were toxic and flammable. The General Motors scientists created a safer refrigerant made from chlorofluorocarbon (CFC).
In the 1980s it was discovered that CFCs were harmful for the environment and partly responsible for creating holes in earth’s ozone layer. They were banned in 1987 and have been phased out of air conditioning systems ever since, replaced by new types of refrigerants that are eco-friendly.
Liquids evaporate when exposed to heat which occurs when liquid refrigerants pass through the interior coils of an AC unit. This cooled refrigerant is warmed by the ambient air inside of a space. The cool coils prompt heat transfer as the air surrounding the coils is cooled and the refrigerant inside the coils starts to warm. The warming refrigerant starts to expand into its gaseous form before being passed into the compressor. Warm gasses under pressure heat up which then causes the pressurized and heated refrigerant to move to the outside condenser unit of an AC system. The pressurized and heated refrigerant is rapidly cooled by being blown through the condenser coils, which causes another phase change that changes the refrigerant back into a liquid state. Once the refrigerant completes the phase change cycle it moves back through the system to extract more heat until a desired temperature is reached, and the AC unit turns off.
Types of AC Refrigerants
Here are primary types of air conditioner refrigerants that have existed.
Chlorofluorocarbons (CFCs)
CFCs were the first types of refrigerants to hit the market. These refrigerants use carbon, chlorine, and fluorine and include refrigerants like R-11, R-12, and R-115. They were phased out by 1995 due to their harmful environmental effects.
R-22
R-22 (also known as Freon 22) is a CFC refrigerant that was standard in air conditioners from the 1960s to 2000s. Unlike previous CFCs, R-22 incorporated hydrogen to minimize its lifespan after being released into the environment. However, the refrigerant still had harmful environmental effects and was banned in 2010. Your AC is probably using R-22 if it was installed prior to 2010.
R-410A
R-410A (also known as Puron) is a refrigerant that is less harmful to the environment because it does not use chlorine. R-410A is beneficial because it:
- Provides better air quality
- Saves you money by being more energy efficient (higher SEER rating)
- Draws less energy from power plants, which reduces carbon emissions
Unfortunately, HVAC systems built for R-22 cannot use R-410A. R-22 systems are not built to handle the higher operating pressures of R-410A.
What Changes in Refrigerant Legislation Means for HVAC Owners
R-22 was banned in 2010. Even still, your AC system probably uses R-22 if it was installed in 2010 or earlier. While it’s not illegal to have an AC unit that operates on R-22, units that rely on R-22 are no longer manufactured.
That can be problematic once your refrigerant levels run low. You might not be able to refill R-22 because the refrigerant is difficult to find on the marketplace now that it’s been banned. You can only buy recycled or reclaimed R-22 and it’s becoming increasingly expensive because there’s a limited supply.
In this case, your best option would be to replace your AC unit with a new model. ACs installed earlier than 2010 are close to replacement age anyway. A new model provides better air quality, higher energy efficiency, and fewer emissions. Plus, modern AC units may come with features like smart thermostats or zoned cooling.
On the other hand, your AC unit is probably using R-410A (or an equivalent) if it was installed after 2010. If this is the case, refrigerant regulations likely have little impact on these homeowners because their systems are up to date.
The Future of Refrigerants
Just like R-22 was phased out, R-410A is also being phased out and replaced by new refrigerants that are more eco-friendly. R-32 will probably be the new standard in HVAC refrigerant.
R-32 produces just 32% of the emissions of R-410A, making it the most environmentally friendly refrigerant on the market. R-32 systems also use up to 20% less refrigerant, which reduces maintenance costs.
R-32 is still catching on in the United States, where it’s commonly used in window-mounted ACs. However, it has been implemented widely in Japan, China, and many other parts of Asia.
How to Tell Which Refrigerant an AC Unit Uses
Your AC unit most likely uses R-22 if it was built in 2010 or earlier. If your air conditioner was installed after 2010, it most likely runs on R-410A and if it is a newer model from after 2015, there is a chance that your AC operates on R-32. The product description sticker on the side of your ACs outdoor unit should provide details on which refrigerant should be used. Alternatively, you can also check the user manual or reach out to your local HVAC company. It is critical to understand which refrigerant your system needs because the different refrigerants are not interchangeable and using the incorrect refrigerant can cause HVAC system failure.
When Do You Need to Refill AC Refrigerant?
Your AC refrigerant is contained within a closed loop system so refrigerant levels don’t deplete rapidly over time. However, refrigerant leaks do happen which can cause refrigerant levels to get low. When this happens, your AC won’t be able to cool your home effectively.The best time to refill your refrigerant is during an annual AC tune-up. During a tune-up, an HVAC technician will check your refrigerant levels and refill the refrigerant, if necessary. They’ll also do a variety of other maintenance tasks that will keep your AC working efficiently. You should schedule AC maintenance at least once or twice per year.
Signs Your AC is Running Low on Refrigerant
Most AC problems are not caused by refrigerant, but leaks do happen on occasion and your AC could have low refrigerant levels if you don’t have the system regularly serviced.
Here are a few symptoms that might indicate low or leaking refrigerant:
- No Cool Air: Your AC blows warm or lukewarm air into your home. This is the most common symptom of low refrigerant. You probably have a refrigerant leak if your AC shifts back and forth from blowing cool air to room temperature air.
- Home Takes Too Long Time to Cool: Your AC will take longer to cool your home when it’s not receiving a sufficient quantity of refrigerant, due to either a leak or low refrigerant levels.
- Higher Electric Bills: You’ll get higher electric bills when your refrigerant is low or leaking because the AC will have to work longer and harder to cool your home.
- Frozen Coils: Ice buildup or water leakage around your AC may indicate frozen coils. This might be caused by a refrigerant leak.
What’s the Solution to an AC Refrigerant Leak
Refrigerant leaks are stressful because they keep your AC from working properly. However, HVAC technicians can easily fix a refrigerant leak through the following steps.
System Assessment
First, the HVAC technician will inspect your AC system and check the refrigerant levels. The technician will also inspect the rest of your system to identify any other malfunctioning components.
Determine the Type of Refrigerant
Next, the HVAC technician will determine the type of refrigerant your AC is using so they can refill it with the proper type. The technician will make recommendations if your AC is using R-22 refrigerant or R-410A.
Locating Refrigerant Leak
The HVAC technician will search for the source of the refrigerant leak. Leaks may occur in the:
Evaporator Coil: The evaporator coil is located inside your AC unit and absorbs heat from your indoor air. Refrigerant leaks on the coil are very small and difficult to detect. HVAC technicians will use a refrigerant sniffer to look for them or do a “soap bubble test” to find bubbles on the coil, which indicate leaking areas. Refrigerant leaks on the coil are the most difficult and expensive to repair.
Refrigerant Lines: The refrigerant lines transport refrigerant in and out of your AC unit. The suction line carries refrigerant gas out of the unit, while the liquid line carries liquid refrigerant back into the AC. These lines can get corroded over time and suffer small leaks.
Condenser Unit: The condenser is the large unit that sits outside your home. The condenser is wrapped ion refrigerant lines, which can get corroded with age.
Repair Leak
Once the technician locates the leak, you may have the option of having the leak sealed or replacing the leaking components. Depending on the age of the HVAC system and cost of repairs, it may be more cost effective to replace the entire system.
- Seal Leaks: Sealing the leaks may be effective if the leaks are small and the parts aren’t in overall bad shape. However, sealing might not work if the leaks are very large, and the parts are severely corroded.
- Replace Leaking Parts: Sometimes the refrigerant leak is too large, and the entire part must be replaced. The replacement cost depends on the part. A leaking evaporator coil is the most expensive, costing between $1,200 – $2,000.
Refrigerant Recharge
After the leak has been repaired, the HVAC technician will “recharge” the refrigerant. In other words, they’ll top off your refrigerant, so you have enough for your AC to work properly.Recharging should only be done by a certified technician due to the high levels of pressure involved in this process. Improper recharging can be hazardous and risk further damage to your air conditioner.
How Long Does an AC Refrigerant Refill Take?
It only takes 5-10 minutes to recharge a pound of refrigerant. The average 3-ton unit can be filled in roughly 2 hours, although larger units that are very low on refrigerant may take 4 hours.
Do You Need to Recharge Your AC Refrigerant Regularly?
Most AC units only need to be recharged every two to five years, if not longer. However, you may need to recharge much sooner than that if you have a refrigerant leak, which will cause your refrigerant levels to drop much more quickly.
You should schedule an AC servicing at least one per year to keep your AC in best shape. The HVAC technician will check your refrigerant levels and make sure there’s no leakage anywhere in your system.
Contact Hurricane AC if You Need Refrigerant Services
Get in touch with us if you live in Southwest Florida and suspect you have low or leaking refrigerant. Our licensed technicians will inspect your AC system and figure out what’s causing the problem. We’ll make repairs as fast as possible, so you don’t have to sweat it out in a humid home. We also offer annual servicing plans, which is the best way to prevent refrigerant leaks, cut your energy bills, and prolong the lifespan of your HVAC system.
