Many vaccines require refrigeration to remain active, and the lack of infrastructure to maintain the cool chain to reliably bring vaccines into more remote areas of developing countries poses a serious challenge to national immunization programs. Portable vaccine cooler units have been proposed by several technologists. The WHO Performance, Quality and Safety (PQS) programme is a driver of the technology. [1] [2]
In 2005 Ian Tansley of Sure Chill designed an ice-chest vaccine cooler regulated by the density of water. Since water has greatest density at around 4 °C, putting the vaccine chamber at the bottom of a thermo-syphon regulates the temperature at between 2 °C and 8 °C, as long as there is ice and the heat-exchange capacity is not overloaded.[ clarification needed ] Sure Chill claimed[ when? ] to be WHO approved and in use for vaccine storage in 46 countries.[ citation needed ]
A refrigeration device was shown for this purpose by Adam Grosser at a TED Talk in 2007, [3] but had not been produced commercially as of 2020. [4] Grosser's proposed device uses exposure to a cooking fire for 30 minutes to store heat. After a cooling period of an hour, the device is placed into a 15-litre container, which contains the vaccine. His concept calls for a 24-hour re-cycle period. [3]
It was revealed in March 2008 that another class of long-term Vaccine Cooler is based around an Ice Box with separate Ice and Vaccine chambers. Using ice as the energy storage device allows the Vaccine Cooler to operate for long periods without power: separating the vaccine chamber from the ice chamber allows temperature regulation while avoiding the need for special packing and conditioning of the cold packs. Suggestions have included the use of a regulated heat pipe to connect the vaccine chamber and the ice chamber. [5]
In September 2008 it was reported that Malcolm McCulloch of Oxford University was heading a three-year project to develop more robust appliances that could be used in locales lacking electricity, and that his team had completed a prototype of his renewal of the Einstein refrigerator. He was quoted as saying that improving the design and changing the types of gases used might allow the design's efficiency to be quadrupled. [6] The three working fluids in this design are water, ammonia and butane. [7]
The Free Piston Stirling Cooler, a type of mechanical refrigerator, was brought to market before 2010 by Twinbird Corporation of Japan. [8] In 2016 Will Broadway won the James Dyson Award for a vaccine cooler based on a miniaturisation of the bi-fluid Icyball technology. Broadway's design uses electricity or propane as the heat source. [9] [10] As of August 2019, Broadway claimed an 88-hour cool-life under WHO PQS test conditions, [11] whereas competitor products could only meet a nine-hour cool-life. [12]
Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one. Refrigeration is an artificial, or human-made, cooling method.
The following is a timeline of low-temperature technology and cryogenic technology. It also lists important milestones in thermometry, thermodynamics, statistical physics and calorimetry, that were crucial in development of low temperature systems.
Thermoelectric cooling uses the Peltier effect to create a heat flux at the junction of two different types of materials. A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other, with consumption of electrical energy, depending on the direction of the current. Such an instrument is also called a Peltier device, Peltier heat pump, solid state refrigerator, or thermoelectric cooler (TEC) and occasionally a thermoelectric battery. It can be used either for heating or for cooling, although in practice the main application is cooling. It can also be used as a temperature controller that either heats or cools.
Thermoacoustic engines are thermoacoustic devices which use high-amplitude sound waves to pump heat from one place to another or use a heat difference to produce work in the form of sound waves.
The Einstein–Szilard or Einstein refrigerator is an absorption refrigerator which has no moving parts, operates at constant pressure, and requires only a heat source to operate. It was jointly invented in 1926 by Albert Einstein and his former student Leó Szilárd, who patented it in the U.S. on November 11, 1930. The three working fluids in this design are water, ammonia, and butane. The Einstein refrigerator is a development of the original three-fluid patent by the Swedish inventors Baltzar von Platen and Carl Munters.
A water dispenser, known as water cooler, is a machine that dispenses and often also cools or heats up water with a refrigeration unit. It is commonly located near the restroom due to closer access to plumbing. A drain line is also provided from the water cooler into the sewer system.
An evaporative cooler is a device that cools air through the evaporation of water. Evaporative cooling differs from other air conditioning systems, which use vapor-compression or absorption refrigeration cycles. Evaporative cooling exploits the fact that water will absorb a relatively large amount of heat in order to evaporate. The temperature of dry air can be dropped significantly through the phase transition of liquid water to water vapor (evaporation). This can cool air using much less energy than refrigeration. In extremely dry climates, evaporative cooling of air has the added benefit of conditioning the air with more moisture for the comfort of building occupants.
A cryostat is a device used to maintain low cryogenic temperatures of samples or devices mounted within the cryostat. Low temperatures may be maintained within a cryostat by using various refrigeration methods, most commonly using cryogenic fluid bath such as liquid helium. Hence it is usually assembled into a vessel, similar in construction to a vacuum flask or Dewar. Cryostats have numerous applications within science, engineering, and medicine.
A refrigerator, colloquially fridge, is a commercial and home appliance consisting of a thermally insulated compartment and a heat pump that transfers heat from its inside to its external environment so that its inside is cooled to a temperature below the room temperature. Refrigeration is an essential food storage technique around the world. The lower temperature lowers the reproduction rate of bacteria, so the refrigerator reduces the rate of spoilage. A refrigerator maintains a temperature a few degrees above the freezing point of water. The optimal temperature range for perishable food storage is 3 to 5 °C. A similar device that maintains a temperature below the freezing point of water is called a freezer. The refrigerator replaced the icebox, which had been a common household appliance for almost a century and a half. The United States Food and Drug Administration recommends that the refrigerator be kept at or below 4 °C (40 °F) and that the freezer be regulated at −18 °C (0 °F).
Cold chain is defined as the series of actions and equipment applied to maintain a product within a specified low-temperature range from harvest/production to consumption. An unbroken cold chain is an uninterrupted sequence of refrigerated production, storage and distribution activities, along with associated equipment and logistics, which maintain a desired low-temperature interval to keep the safety and quality of perishable or sensitive products, such as foods and medicines. In other words, the term denotes a low temperature-controlled supply chain network used to ensure and extend the shelf life of products, e.g. fresh agricultural produce, seafood, frozen food, photographic film, chemicals, and pharmaceutical products. Such products, during transport and end-use when in transient storage, are sometimes called cool cargo. Unlike other goods or merchandise, cold chain goods are perishable and always en-route towards end use or destination, even when held temporarily in cold stores and hence commonly referred to as "cargo" during its entire logistics cycle. Adequate cold storage, in particular, can be crucial to prevent quantitative and qualitative food losses.
An icebox is a compact non-mechanical refrigerator which was a common early-twentieth-century kitchen appliance before the development of safely powered refrigeration devices. Before the development of electric refrigerators, iceboxes were referred to by the public as "refrigerators". Only after the invention of the modern electric refrigerator did early non-electric refrigerators become known as iceboxes. The terms ice box and refrigerator were used interchangeably in advertising as long ago as 1848.
An icemaker, ice generator, or ice machine may refer to either a consumer device for making ice, found inside a home freezer; a stand-alone appliance for making ice, or an industrial machine for making ice on a large scale. The term "ice machine" usually refers to the stand-alone appliance.
Icyball is a name given to two early refrigerators, one made by Australian Sir Edward Hallstrom in 1923, and the other design patented by David Forbes Keith of Toronto, and manufactured by American Powel Crosley Jr., who bought the rights to the device. Both devices are unusual in design in that they did not require the use of electricity for cooling. They can run for a day on a cup of kerosene, allowing rural users lacking electricity the benefits of refrigeration.
An absorption refrigerator is a refrigerator that uses a heat source to provide the energy needed to drive the cooling process. Solar energy, burning a fossil fuel, waste heat from factories, and district heating systems are examples of convenient heat sources that can be used. An absorption refrigerator uses two coolants: the first coolant performs evaporative cooling and then is absorbed into the second coolant; heat is needed to reset the two coolants to their initial states. Absorption refrigerators are commonly used in recreational vehicles (RVs), campers, and caravans because the heat required to power them can be provided by a propane fuel burner, by a low-voltage DC electric heater or by a mains-powered electric heater. Absorption refrigerators can also be used to air-condition buildings using the waste heat from a gas turbine or water heater in the building. Using waste heat from a gas turbine makes the turbine very efficient because it first produces electricity, then hot water, and finally, air-conditioning—trigeneration.
A pot-in-pot refrigerator, clay pot cooler or zeer is an evaporative cooling refrigeration device which does not use electricity. It uses a porous outer clay pot containing an inner pot within which the food is placed. The evaporation of the outer liquid draws heat from the inner pot. The device can cool any substance, and requires only a flow of relatively dry air and a source of water.
A refrigerated container or reefer is an intermodal container used in intermodal freight transport that is capable of refrigeration for the transportation of temperature-sensitive, perishable cargo such as fruits, vegetables, meat, and other similar items.
Vaccine refrigerators are designed to store vaccines and other medical products at a stable temperature to ensure they do not degrade. In developing countries with a sunny climate, solar-powered vaccine refrigerators are common.
A solar-powered refrigerator is a refrigerator which runs on energy directly provided by sun, and may include photovoltaic or solar thermal energy.
Sure Chill Technology is a cooling technology that is currently being used in medical refrigerators, but is thought to have wider potential in the future for domestic refrigerators and beverage coolers. According to BBC, the refrigerator's temperature 'can stay at 4°C for more than 10 days without power, and is used mainly in Africa' to store vaccines and other medical supplies. It can be powered by electricity or solar, and uses the physics of water to store energy, thus not relying on batteries.
Vaccine storage relates to the proper vaccine storage and handling practices from their manufacture to the administration in people. The general standard is the 2–8 °C cold chain for vaccine storage and transportation. This is used for all current US Food and Drug Administration (FDA)-licensed human vaccines and in low and middle-income countries. Exceptions include some vaccines for smallpox, chickenpox, shingles and one of the measles, mumps, and rubella II vaccines, which are transported between −25 °C and −15 °C. Some vaccines, such as the COVID-19 vaccine, require a cooler temperature between −80 °C and −60 °C for storage.
I discovered a 1929 forgotten cooling invention called 'Icyball' that had no moving parts and provided rural farmers access to off the grid refrigeration. I refined the cast iron technology for use as a portable, controllable cooling device.