The basic concepts behind heating and cooling have been the same for decades. While some of the principles are easy to understand, like the burning of fuel to make heat, the role of refrigerants is a bit more complicated. Here is a look at the history of refrigerants and their role in both heating and cooling your home.
What Is a Refrigerant? When Were They Invented?
Refrigerants are a class of chemicals that will absorb or release heat when exposed to different pressure levels. The basic concept behind refrigerants was originally proposed in 1748 by William Cullen at the University of Glasgow. The technique of using vapor pressure to transfer heat was first used in refrigerators and was then expanded to heating and cooling systems.
An inventor named Oliver Evans designed the original blueprint for this type of system in 1905, but he never built it. An Austrian expert in minerals named Peter Von Rittinger, however, built the first proper heat pump in 1857. It took until 1879 for someone to patent the process of turning gas to a liquid in a refrigerator, however, and Willis Carrier didn’t patent the modern air conditioner until the year 1902.
Common types of refrigerants include the following:
This was the most common class of refrigerant in HVAC systems until the late 1980s. Freon, or R12, is a CFC that was widely used in refrigerators and HVAC systems. After studies linked it to holes in the ozone layer, the United Nations enacted a treaty called the Montreal Protocol, which led to a full ban on the production of Freon in 1996.
Though HCFCs are technically adjacent to CFCs, they emerged as an alternative to refrigerants like Freon in the 1980s. Once countries banned Freon and other CFCs, they began to rely more on HCFCs like R22. However, though their impact isn’t as dramatic as CFCs, HCFCs still deplete the ozone layer. As a result, the United Nations updated the Montreal Protocol to phase the chemical out, and the United States required manufacturers to stop the production and new use of most HCFCs as of 2020.
The chlorine molecule is the part of refrigerants that can degrade ozone. In the search for a more environmentally friendly refrigerant type, countries began introducing the use of HFCs. The most common HFCs are R410A and R134, which you might find in air conditioners and heat pumps. Because HFCs don’t have any chlorine, they don’t deplete the ozone layer, making them safer for the environment.
It is important to note that the bans on using and producing chemicals like CFCs don’t apply to systems that are currently in use. That means that you may still find systems that use Freon, for example. The number of systems using ozone-depleting refrigerants shrinks as time goes on thanks to the ban on production, though.
How HVAC Systems Use Refrigerant
Where furnaces burn fuel in order to generate heat, many HVAC systems use refrigerant for both heating and cooling. Heat pumps can use refrigerant for both, but air conditioners lack the capability to heat your home with refrigerant. Contrary to what its name may imply, refrigerant transfers heat between locations instead of simply making them colder.
Systems that use refrigerants to condition your home will have both indoor and outdoor components. The refrigerant passes through both parts of the system in a loop.
When an air conditioner takes in air from your home, it blows it over a coil filled with cold liquid refrigerant. That refrigerant pulls the heat from the air your system takes in, turning into a gas. While the blower returns the now-cooled air to your home, a component called a compressor pressurizes the refrigerant, increasing its temperature further and sending it to your outdoor unit.
That’s where refrigerant expels the heat, turning back into a liquid in a part called a condenser. An expansion valve then helps lower the refrigerant’s pressure, reducing its temperature so it can flow back into your home and begin the process again.
Heat pumps have an extra part called a reversing valve, which makes the process go in reverse, as you might guess. This lets them warm your home by pulling heat energy from the air outside, then expel it inside.
Heat Pumps, Air Conditioners and Efficiency
Compression of refrigerant is a much more energy-efficient process than burning fuel or generating heat through electricity. The US Department of Energy estimates that homeowners who switch from electric heating systems to a heat pump can reduce the electricity used to heat your home by 65%. You can also find dual-fuel heat pumps that combine an electric heat pump unit with a gas-powered backup furnace.
There are some limitations to heating with a heat pump, however. Because the process relies on pulling heat from ambient air, it becomes less efficient as the temperature drops. The system works relatively slowly, also. Many HVAC professionals will pair a heat pump with a smaller furnace that only works when your home is undergoing a rapid temperature change or when the outside temperature drops too low, called a hybrid system
Refrigerants in Mini-Splits
You might have heard of ductless mini-splits, which function the same way as heat pumps. They’re fully functional heat pumps on their own — the difference is that mini-splits don’t rely on ductwork. Where traditional heat pumps and central air conditioners use blowers to push air through a home’s ductwork to its final destination, mini-splits can have multiple air handlers that connect to a single outdoor unit. Air handlers condition specifically the area where they’re located instead of being responsible for the entire home. This allows for zone-based heating and cooling without the need to modify systems of ductwork.
Maintenance for Refrigerants
During annual maintenance, your HVAC professional will clean and inspect your system’s evaporator coils and condensers. They will remove water from the drain pans and check any drain lines for clogs, as well as inspect refrigerant levels to see if there is any possibility of leaks. If refrigerant levels are low, they will top the system off.
They will also inspect the connections between refrigerant lines, air handlers and condensers for areas where they may become loose. Regular maintenance can maintain the efficiency of these HVAC systems and identify potential issues with your refrigerant lines before they become leaks.
Refrigerant chemicals can be dangerous in a number of ways. Refrigerant gases can cause asphyxiation and toxicity. They may be flammable, and their extreme temperatures can cause burns or frostbite. Because of this, experts recommend that you allow solely professionals trained in the safe use of refrigerants to handle these chemicals.
Work With the Pros to Learn More
If you are in the Norman area, contact Norman Air to learn more about how refrigerants work in your home’s HVAC system. We’ve been providing heating and cooling installation, maintenance and repair since 2008. We also provide a variety of other services with licensed electricians and plumbers! From installing a new charging station for an electric vehicle to fixing broken pipes and more, Norman Air is your go-to. Call us at Norman Air today!