Catch up with this deep dive on natural refrigerants.
Natural refrigerants
We call them “natural refrigerants” because they are comprised of substances that occur directly in nature and our environment. The most widespread natural refrigerants used in HVAC/R applications today are carbon dioxide (CO2, R-744), hydrocarbons such as propane (R-290), isobutane (R-600a), and propylene (R-1270), and ammonia (NH3, R-717).
The primary advantage of natural refrigerants is their climate-friendliness: the direct emissions of natural refrigerants have no, or negligible, impact on the climate.
However, strictly speaking, even though natural refrigerants are made from naturally occurring substances, they must be manufactured industrially like any other refrigerant. They are combined with other natural substances or purified and refined to be used in a refrigerant capacity.
We'll evaluate the merits of both organic natural refrigerants and inorganic below.
Organic natural refrigerant vs inorganic natural refrigerant
In order to fully answer this question, it is important to distinguish the term "organic" as it refers to science and "organic" as we think of regard to agriculture.
Organic in science
With very few exceptions, a chemical is classified as organic if it contains at least one carbon atom, regardless of its source. This is why organic chemistry is called “the chemistry of carbon.”
Not all carbon-based molecules are organic. Some, such as carbon dioxide (or CO2), can be “inorganic.” The lack of hydrogen is why many chemists classify carbon dioxide this way. To be “organic,” these chemists argue, a molecule must combine its carbon with some hydrogens.
Organic in agriculture
An organic food or any food that is organically grown (i.e. grown without using or applying synthetic pesticides, fungicides, inorganic fertilizers, or preservatives.)
Are organic natural refrigerants better?
When it comes to natural refrigerants, organic--rather than signaling “not including chemicals”--is merely a designation of including exclusively Hydrogen and Carbon molecular compounds. As you can see below within the natural refrigerants classification, Hydrocarbons are considered the only “organic” natural refrigerants. Whether or not a substance is an organic natural refrigerant is basically irrelevant in terms of environmental impact; the "natural" part of "natural refrigerants" is the more important classification, because natural refrigerants as a group do not have a negative effect on the environment. This impact is not affected by the additional classification of "organic."
Below is a recap of the major natural refrigerants used today including organic natural refrigerants and inorganic natural refrigerants.
R-290, R600a, and R-1270 Hydrocarbons (organic)
They consist entirely of hydrogen and carbon and are considered organic. In the refrigeration and air conditioning world, hydrocarbons can be used as refrigerants. Some of the most commonly used hydrocarbon refrigerants are Propane (R-290), Isobutane (R-600a), and Propylene (R-1270).
They are natural, nontoxic refrigerants that have no ozone-depleting properties and low global warming potential. Hydrocarbons are one of the most climate-friendly and cost-effective refrigerants to cool and freeze.
R290 (HC) refrigerant is highly refined propane that is a safe, environmentally friendly alternative for the hydrofluorocarbon (HFC) refrigerants R134a in refrigerator applications and R404a in freezer applications
R-717 = Ammonia( inorganic)
Ammonia, R717, is an attractive refrigerant alternative.
It has been used in refrigeration systems since 1840 and in vapor compression since 1860.
Its ODP and GWP are 0
As a self-alerting gas, leaks can easily be detected by the smell. Ammonia is very hazardous to even at low concentrations because the smell often causes panic. This is the main reason why ammonia was withdrawn from applications for use by unskilled people and retained only for industrial applications.
R-744 Carbon Dioxide (inorganic)
From an environmental perspective, CO2 is a very attractive refrigerant with zero ODP and a GWP of 1.
It is a naturally occurring substance and abundant in the atmosphere.
CO2 is a high-pressure refrigerant where high operating pressures are required for efficient operation.
Should you choose organic natural refrigerants?
Ultimately, that's up to you. We suggest you base your decision on several factors: budget, application, and location. If hydrocarbons, i.e. organic natural refrigerants, end up the best solution for you, that's great. If not, your climate impact remains the same. The best criterion is simply to keep it natural.