What did old refrigerators work on: ammonia, kerosene and gas

In the modern world, it is difficult to imagine a kitchen without a familiar electric unit that silently keeps food fresh. However, the history of household cooling goes back more than a century and a half, and the first devices looked completely different. Before the widespread introduction of compressor systems, engineers used physical and chemical processes that seem incredible today.

Many people mistakenly believe that cold in the past was created exclusively with the help of ice brought from the northern regions. In fact, even before widespread electrification, there were complex mechanisms that ran on gas, liquid fuel, and even without moving parts at all. Understanding how these devices worked helps you better appreciate the reliability of modern systems and the principles of thermodynamics.

In this article we will examine in detail the evolution of refrigeration technologies, from the simplest glaciers to the first absorption models. You will learn why ammonia became the main refrigerant of the past and how the kerosene burner could cool food better than some modern analogues.

The Age of Glaciers and Natural Cold

The first and most common "refrigerator" in history humanity was glacier. This device was a thermally insulated box, usually wooden, lined with metal or zinc on the inside. The principle of operation was primitive: a huge piece of natural ice was placed in the upper part of the box, which, when melted, took away heat from the products located below.

Condensation from the melting ice was collected in a special tray, which required regular cleaning. The efficiency of such cooling directly depended on the quality of the thermal insulation of the walls. For this they used cork, sawdust, felt or even bird feathers. Thermal conductivity materials were then the main enemy, which was fought by any available means.

⚠️ Attention: Glaciers required a constant supply of ice, which was carried out by ice carriers. In the summer, ice losses during delivery and storage could reach 50%, which made refrigeration of products a luxury for the wealthy.

Despite their simplicity, such devices provided a temperature of about 0...+5°C, which was enough for short-term storage of meat and dairy products. However, they could not freeze water or create the low temperatures required for long-term preservation. It was more of an improved version of the cellar than a full-fledged refrigerator.

The principle of absorption: cold without moving parts

The invention of absorption refrigerators was a real revolution. Unlike modern compressor models, they had no moving mechanical parts such as pistons or valves. The basis of the process was absorption the absorption of a gaseous substance by a liquid solvent.

In the classical scheme, developed in the middle of the 19th century by French engineers Carré, a mixture of water and ammonia was used. Heating this mixture in a generator led to the release of ammonia vapor, which then condensed and evaporated, removing heat. The key element was diffuserwhich ensures the circulation of gases due to the difference in density.

The main advantage of such systems was their noiselessness and durability. The absence of rubbing parts meant that there was practically nothing to break. The service life of such units often exceeded 30-40 years, and the only consumable material was the refrigerant itself, which, however, rarely required replacement.

Gas and kerosene refrigerators

In regions where electrification was late, or in mobile conditions (for example, in caravans and yachts), refrigerators powered by liquefied gas or kerosene. The energy source was a conventional burner that maintained a constant temperature in the absorption system generator.

Kerosene models were especially popular at the beginning of the 20th century. They worked on the principle of a wick lamp: kerosene was fed into a burner, where it burned, heating the lower part of the absorption circuit. This made it possible to reach freezing temperatures even in the complete absence of infrastructure.

Gas units running on propane-butane have become the standard for motorhomes. Their design allowed them to work for months without human intervention, except for the need to periodically clean the burner from combustion products. Heat exchanger in such models it had to be perfectly tuned so that the flame did not smoke and gave off maximum energy.

The safety of using open fire inside residential premises has always remained under control. The design of the burners included systems for cutting off the gas supply when the wick extinguished, but the risk of fuel leakage remained a factor requiring constant attention of the owners.

Comparison of energy sources: table of characteristics

To better understand the differences between the technologies of the past, it is worth comparing their key parameters. Each of the systems had its own unique advantages and disadvantages, which determined the scope of their application.

As can be seen from the table, absorption systems won in reliability and silence, but lost in energy efficiency. Efficiency factor (efficiency) heat pumps of that time were significantly lower than those of mechanical compressors, which made them more “gluttonous.”

Nevertheless, for dachas or places with unstable network voltage, gas and kerosene models remained the only choice for many decades. They could work for weeks without supervision, which was critical for remote weather stations or geological camps.

Refrigerants of the past: ammonia and methyl chloride

The most important component of any refrigerator is the refrigerant - a substance that circulates in the system, changing its state of aggregation. In older models, especially absorption ones, it became the standard ammonia. This substance had excellent refrigeration properties, but was toxic and flammable in high concentrations.

In compressor machines of the early 20th century, methyl chloride, sulfur dioxide and even butane were often used. These substances were effective, but had serious drawbacks: they were poisonous, had a strong odor, or were explosive. A leak of such refrigerant in a small kitchen could lead to tragedy.

⚠️ Warning: Ammonia, used in old refrigerators, forms explosive compounds when it comes into contact with copper. Therefore, it was strictly forbidden to use copper tubes in the circuits of such systems, using only steel.

The situation changed only in the 1930s with the invention of freons (freons). These synthetic gases were inert, odorless and non-toxic in small doses. It was the advent of freons that made it possible to move the refrigeration unit from the basement or separate room directly to the kitchen.

The first electric compressor systems

In parallel with the development of absorption technologies, compressor systems were also improved. The first electric refrigerators were bulky, noisy, and difficult to maintain. The motor-compressor was often located in the basement or in the yard, and only a pipeline with refrigerant led into the kitchen.

Electric motors of that time worked on the principle single-phase asynchronous motor. They were heavy and consumed a lot of energy. The inrush current of such units could cause light bulbs throughout the house to blink when turned on. Temperature adjustment was carried out manually, often by changing the position of the thermostat, which was a simple bimetallic sensor.

Despite the inconvenience, mechanical gas compression made it possible to reach lower temperatures faster than absorption. This opened up new possibilities for storing food and preparing frozen meals. The competition between “thermal” and “mechanical” refrigerators has been going on for many years.

Over time, engineers managed to compact the compressor, introduce effective noise insulation and create sealed casings. This made it possible to combine all the nodes into a single block, which we see in modern models. However, the operating principle laid down in those distant years remains unchanged to this day.

The legacy of old technologies in modern times

It would seem that the technologies of the past have irrevocably gone into history, giving way to inverter compressors and smart control systems. However, the principles discovered more than a hundred years ago continue to serve man. Absorption refrigerators are still indispensable in motorhomes, hotel rooms and office bars due to their quietness.

Modern absorption refrigerators often run on electricity (using a heating element instead of an open flame), while maintaining the main feature of their ancestors - the absence of moving parts. This makes them ideal for environments where silence is the number one priority.

Learning what old refrigerators ran on gives us insight into the fundamental laws of physics. From simple evaporation of water to complex cycles of ammonia compression - each stage of evolution was a step towards creating a comfortable living environment. It was the combination of the absorption principle and gas heating that made it possible to create the first autonomous refrigerators that did not depend on electrical networks.

Today, looking at rare models in museums or parts of collections, we see not just pieces of metal, but the embodiment of engineering, which was able to beat the heat long before the advent of air conditioners and modern split systems.