For an assessment of the advancements in refrigeration technology, Hormel Foods asked journalist J.K. Rose to investigate the promising developments occurring in the industry today — and on the horizon.
Look around any urban neighborhood and you’ll see the web of equipment we rely on for cooling — the massive HVAC systems on the rooftops of hospitals, businesses and schools; the AC units wedged into apartment windows; the refrigerated trucks delivering perishable food to supermarkets and crucial vaccines to hospitals. And then there’s all the gear that’s out of sight — household refrigerators, car air conditioners and grocery store coolers. In a warming world, we’ve become increasingly dependent on air-conditioning and refrigeration. According to the International Energy Agency, an international nonprofit that tracks environmental concerns, the number of AC units sold globally is expected to jump 244% by 2050.
It’s a huge problem, but seen through an innovator’s lens, it’s an equally huge opportunity. Scientists and entrepreneurs worldwide are developing a host of alternate refrigerants and innovative cooling technologies that will increase efficiency and help us make a dent in the climate crisis.
|Company / Organization||Tech||Area|
|Exergyn||Nickel-titanium alloy||Solid-state cooling|
|Barocal||Malleable plastic crystals||Solid-state cooling|
|UC Berkeley||Iodine / sodium / ethylene carbonate||Solid-state cooling|
|Matelex||Remote monitoring & predictive analytics||Refrigerant leak detection|
|Hussman Corp||Remote monitoring & predictive analytics||Refrigerant leak detection|
|Thermo King||Trucking refrigeration units||Transportation|
|Oxycom||Evaporative cooling||Food production facilities|
|Sono Motors||Solar paneling to power refrigerated trucks||Transportation|
The companies listed in this table are developing technology to help industries become more energy efficient and innovative. Their appearance on the list does not imply an association with Hormel Foods. Hormel Foods does not endorse these companies.
Advances in Solid-State Cooling
The Clean Air Act requires companies to properly dispose of hydrofluorocarbons (HFCs) used in refrigeration and air-conditioning to prevent them from reaching the atmosphere, either by incineration at temperatures of over 1800 degrees Fahrenheit or by recycling them back into existing cooling systems, which just pushes the emission problem down the road.
Scientists around the world are testing the ability of solid materials to transfer heat through pressure, stretching or magnetism, taking advantage of how heat is stored or released when a material changes shape.
An Irish startup, Exergyn, is developing a cooling device that uses a metal alloy of nickel and titanium. Barocal Ltd., based in the UK, is working on a cooling technology using malleable plastic “crystals.” And at the Berkeley Lab in California, researchers are experimenting with a salt compound made with iodine and sodium and ethylene carbonate, an organic solvent used in lithium-ion batteries.
Leaky cooling systems are hard to detect and tend to lose 20%–30% of their refrigerant gases before the problem is noticed. At home, a wonky fridge can lead to curdled milk or moldy food. In the private sector, refrigerant leaks in manufacturing facilities or grocery stores can lead to costly loss of product.
Two American companies are developing software systems to detect leaks in commercial facilities before they provoke pricey meltdowns. Matelex and Hussmann offer remote monitoring systems that combine sensors installed on cooling systems as well as predictive analytics to collect data on pressure, temperature and refrigerant volume. When the software notes an imbalance, the administrator is alerted so leaks can be fixed before they lead to a system failure.
Improving the Cold Chain
We rely on “cold chains” to preserve our food as it makes its way from farm to table. The cold chain includes post-harvest forced-air chillers, refrigerated trucks and shipping containers, and industrial cold storage.
If a link in the chain fails, the loss can be catastrophic. According to the International Institute of Refrigeration, 1.6 billion tons of food are wasted each year in the global food system, 30% of which could be saved by refrigeration. This lost harvest would be enough to feed 950 million people.
A host of new technologies has emerged to green up the cold chain. Thermo King makes electric refrigerated trucks that use zero-emission batteries to chill merchandise. Likewise, Sono Motors makes refrigerated trucks covered with solar panels, taking advantage of the sun’s energy. Geothermal cooling systems are increasing in popularity in the home construction industry, and the same approach will work for cooling food storage facilities. Oxycom uses water as a refrigerant to cool production facilities and warehouses.
“The amount of refrigerants emitted across the globe each year have more climate impact than all the trains, ships, buses, airplanes in the United States,” says Tilden Chao, a refrigerant expert at the Yale Carbon Containment Lab. “It’s a very large issue — but in a narrow sector. So targeted intervention can do a lot of good.”
Carbon Dioxide on Steroids
Hydrofluorocarbons were developed in the 1970s as replacements for chlorofluorocarbons and hydrochlorofluorocarbons — refrigerants containing chlorine were found to deplete the ozone layer. But then scientists discovered that HFCs, while not ozone-depleting, were what one professor of atmospheric science called “carbon dioxide on steroids.” In the wake of this discovery, more than 150 countries have signed a treaty to phase out HFCs by 2047. In the United States, the American Innovation and Manufacturing Act requires the use and manufacture of fluorinated gases to drop by 85% over the next 15 years.
The good news is that climate-friendly coolants and technologies already exist.
Although there are no “drop-in” substitutes for HFCs, Chao says, they can be blended with HFOs (hydrofluoroolefins), although some scientists worry that HFOs are a “forever chemical” that may harm human health and the environment.
Meanwhile, natural refrigerants that were popular in the 1800s are making a comeback, including propane, carbon dioxide and ammonia. Each of these alternatives has its own challenges and will require new equipment and retraining of technicians.
Ammonia is readily available, inexpensive, operates at pressures comparable to other refrigerants, and absorbs large amounts of heat.
Carbon dioxide is a greenhouse gas, but its use as a refrigerant is considered benign because the CO2 used in cooling systems is recovered from industrial waste, resulting in a net zero greenhouse impact. The main challenge to using CO2 is that it operates under very high pressure, making it more vulnerable to leaks.
Hydrocarbon refrigerants such as propane are cheap and have excellent environmental, thermodynamic properties — but are also highly flammable.
These old options combined with new research and innovative technologies point to ongoing advances in how we keep things cool. The greenest alternative for cooling interiors? Better building design: using dense materials such as stone, concrete and earth and planting shade trees helps maintain cool spaces without chemicals.