AC and Heating Tip from AC Express
Refrigerant: History and Future
Air conditioning in Austin requires the perfect combination of the right components, substances, and conditions. Refrigerant is like the lifeblood of your air conditioning system. It flows through the inner workings of the air conditioner and cools down the air that is then blown into your home. It’s as much a staple technology in the world of air conditioning as fans. But things are changing in the world of HVAC right now, and part of that change has to do with the history and future of refrigerant.
In this tip, we’ll go over everything noteworthy about refrigerant. Starting out, we’ll go into some of the science behind refrigerant and how it works. What exactly does it do and how does it do it? Then we’ll go over some of the more common types of refrigerants through time including some new breeds that we’ll all be seeing more of soon. We’ll be seeing more of them because of new regulations put forth that aim to make our air conditioning systems more environmentally friendly. This is a big deal, because it links the humble world of commercial and residential air conditioning and heating with the world of environmental preservation and the ongoing climate change battle.
How Refrigerant Works
Refrigerant is a type of liquid that is used in the heating and air conditioning cycle. Through the cycle it typically undergoes phase changes from a liquid to a gas and then back to liquid again. There are four main components of an air conditioner and the refrigerant is the substance that flows through this system of four components in order to cool the air. Those components are the compressor, the condenser, the evaporator, and some sort of expansion or throttling device.
The refrigerant flows through this system in a closed loop. It’s important to understand this because it means that refrigerant isn’t used up by the system. The amount of refrigerant in your air conditioner will remain the same unless there’s a leak. Because the refrigerant flows around the system in a closed loop, we could pick any point to begin our tour of the system. Let’s start at the input to the evaporator unit. This is usually a copper tube with metal fins attached. The refrigerant enters the evaporator at its coldest, usually around 32 degrees. The fins are cooled and this removes heat from the air which is then conducted into the refrigerant. This causes the refrigerant to change from a liquid to a gas. That’s why only substances with very specific thermodynamic properties can be used as refrigerant.
Then it moves on to the compressor, which does as its name suggests, and compresses. It adds pressure to the gas state refrigerant which leaves us with a very high pressure, hot gas. The compressor also helps to keep the refrigerant flowing steadily through the cycle. The refrigerant then moves on to the condenser. So now we have a hot, high pressure gas that needs to become a cold, low pressure liquid by the end of the cycle. The condenser is kind of like the opposite of the evaporator. As the refrigerant flows through it the heat of the refrigerant is dumped into the surrounding atmosphere. As the temperature of the refrigerant drops it turns back into a liquid. Finally, the refrigerant flows through some kind of valve that restricts flow. What this does is it causes the refrigerant to change from high pressure to low pressure, and in doing so, the temperature drops further. This gives us our end result to start the cycle all over again, cold, liquid refrigerant.
Noteworthy Types of Refrigerant
What makes a good refrigerant? Well, there are several properties that a substance must have in order to work as a refrigerant, and several properties that would be ideal but not necessary. There are thermodynamic requirements that a substance must have in order to be a refrigerant. It must be a liquid that changes state from liquid to gas, or boils, at a temperature much lower than water. The ideal refrigerant has a boiling point somewhat below the target temperature. This ideal refrigerant is also going to have a high heat of vaporization, which is energy that must be added to the substance, typically a liquid, to transform a quantity of that substance into a gas. It should also have a somewhat moderate density when in liquid form.
The reason there isn’t just one type of refrigerant that everyone uses is that there are trade-offs. It’s not that easy to find a substance that fulfills all the hallmarks of an ideal refrigerant. The ideal refrigerant would have all the favorable thermodynamic properties mentioned above, and would in addition be noncorrosive to mechanical components, safe, including free from toxicity and flammability. It would not cause ozone depletion or have an effect on climate change. Since different fluids have the desired traits in different degrees, choice is a matter of trade-off.
R-22, also known as Freon, was the most commonly used refrigerant throughout the 20th century. Although technically, Freon refers to all refrigerants manufactured by the Chemours Company, including R-12, R-13B1, R-502 and R-503. This type of refrigerant is being used more and more in developing countries but is beginning to be phased out of use in the European Union and the United States. That’s because of the ozone depleting effects of R-22, R-12, and many other types of refrigerant substances that were used almost exclusively throughout the 20th century.
R-401A goes by the brand name Puron. It has been approved for new systems and has become widely common especially in commercial use. It has a much less significant effect on ozone depletion than R-22 which makes it a good alternative. The main drawback is that R-410A operating pressures are more than 50% higher than R-22 and R-410A systems require components capable of working at these higher pressures.
R-407C is often referred to by a brand name such as Suva or Genetron. R-407C is a hydro-fluorocarbon refrigerant that does not contribute to ozone depletion. Of the higher temperature refrigerant options, R-407C most closely matches the operating characteristics of R-22 making it a solid replacement. It is a high-glide refrigerant with lower efficiency, but provides the simplest conversion from R-22 due to its similar pressures.
R-134a is commonly used in many air conditioning and refrigeration systems globally. It is a hydro-fluorocarbon type of refrigerant that does not contribute to ozone depletion. It also holds the record of being the first non-ozone-depleting fluorocarbon refrigerant to be commercialized. It is a single-component refrigerant with no glide, featured in many large commercial screw chillers.
R-32 is a new type of refrigerant that is currently gaining some interest. R-401A may have very little effect on the ozone compared to older type of refrigerant such as R-22, but there are still questions about its overall environmental impact. R-32 is being touted as the most environmentally friendly refrigerant compound yet. It also conveys heat very effectively making it around 10% more energy efficient than other similar compounds.
There is a long history of changing regulations around refrigerants as more is discovered about their environmental effects. It started with the Montreal Protocol of 1987. This set the date of 2013 as the time to freeze the consumption and production of HCFCs, a category of refrigerants that have been shown to cause damage to ozone layer. This Montreal Protocol has the full name The Montreal Protocol on Substances that Deplete the Ozone Layer. It was an international treaty with the goal of fighting the reduction of the ozone layer.
More categories of ozone depleting refrigerant compounds were added to the list of those to be phased out with the introduction of the Kyoto Protocol in the 90s. In 1997, FCs and HFCs were included in the Kyoto Protocol to the Framework Convention on Climate Change. In 2006, the EU adopted a Regulation on fluorinated greenhouse gases, which makes stipulations regarding the use of FCs and HFCs with the intention of reducing their emissions. The provisions do not affect climate-neutral refrigerants.
And then as recently as this September, new requirements have been put into place by the EPA, the environmental protection agency. The rule is slated to come into action in January of 2017 and expands the requirements of Clean Air Act Section 608 to non-ozone depleting substitutes such as hydrofluorocarbons. The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) very recently expressed disappointment in this act as they petitioned to have the date moved to 2025. They released a statement saying “making compliance a year sooner has a negligible benefit for the environment, but it does create an economic burden for the industry that provides comfort cooling and heating, commercial refrigeration technologies, and hot water for every American.”
Refrigerant and Air Conditioning Repair in Austin
That’s a rundown on refrigerant in this day in age. It’s a somewhat controversial subject just because of the nuanced issues that deal with the ozone and climate change effects of these substances that are so widespread and commonly used. There are many factors to consider when talking about what compounds make for the best refrigerants. The day we live in now is one of change when it comes to air conditioning technology. The next few years will see a slow shifting as new refrigerant types come more into use and the technology that uses them will have to change as a result.
Regardless of all of that though, what’s really important to remember is that a refrigerant leak can be serious issue that can affect anyone’s air conditioning in Austin. Austin AC repair companies like AC Express are suited to repair and replace refrigerant leaks. AC repair in Austin doesn’t have to be a hassle. AC Express performs its services all around the Austin area, from Pflugerville and Round Rock to Kyle and Hutto. Call AC Express to get top quality same day AC repair and you’ll have your Austin air conditioning back to full strength in no time.
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