The mechanical aspect of the cycle starts with a compressor, a combination electric motor and pump. In the compressor, a low pressure, gaseous refrigerant is squeezed down to a greatly reduced volume. This compression raises the refrigerant’s temperature and pressure and pushes it into the next component, the condenser. The condenser is merely a coil of tubing over which air can flow. In the condenser, the high pressure/high temperature gas releases its heat and becomes a liquid.

One will often feel the heat thrown off by a condenser on the back of a household refrigerator or from the outdoor coil component of a central air conditioner. The heat being dumped out was originally absorbed by the refrigerant in the air conditioned space. The now-liquefied refrigerant flows on through the condenser because the compressor maintains pressure behind it.

 

A heating, ventilation, and air conditioning (HVAC) technician installs and repairs commercial and residential heating, cooling, and refrigeration equipment. You can prepare for this job by graduating from high school and then pursuing HVAC education in a certificate, diploma, or degree program. You will usually need training as well, which you can obtain through an internship, apprenticeship, or job. Certification and licensing requirements typically vary by jurisdiction; if either is required, or preferred, you will typically have to demonstrate proof of your training or educational background and pass an exam to earn it.

Compressor oil is a lubricant used to prevent wear, minimize corrosion of metals and improve compression efficiency. Oils vary by thickness or viscosity, the types of additives used, and whether they are natural or synthetic oils. They can circulate with the gases being compressed, such as in air conditioning systems, or be separate, as in oxygen compressors.

Synthetic compressor oil is made from artificial lubricants rather than natural petroleum oils. Different molecules are mixed to provide wear protection, proper viscosity and high-temperature stability. Compressors for oxygen and other gases that can cause combustion may use synthetic oil because mixtures can be used that do not burn in the presence of oxygen.

Many systems, such as used for air conditioning and refrigeration cooling, circulate oil and refrigerant in the system as a mixture. The compressor oil provides lubrication while it is inside the compressor, but is not stored there. Moving lubricant through a system can provide cooling for the compressor, because the hot oil will be cooled in the heat exchangers before returning. These systems can also be less expensive to produce, because extra equipment is not needed to keep the oil separated.

 

The best methods for recycling refrigerant require an explanation of what refrigerant is and its role in the cooling cycle of refrigerators, freezers, air conditioners and other appliances. Refrigerants are compounds used in cooling that are boiled from liquid to gas then condensed back to liquid. In the 1980s, many of those compounds were discovered to be major contributors to ozone depletion. Since the Montreal Protocol (1987), countries all over the world are agreeing to phase out toxic refrigerants and other hydrochlorofluorocarbons (HCFCs) with natural, environmentally friendly compounds.

Oil separation is one method of cleaning then recycling refrigerant. The compound can also be filtered through a filter/drier device several times. This process decreases moisture, acids and particulates in the refrigerant.

Different types of refrigerant scales also offer varying levels of precision. Sensitive systems may require a refrigerant scale with very precise measurements, while very large systems may not require a high level of precision. Some of these scales are built to withstand high temperatures, or to measure refrigerant under high levels of pressure. These heavy-duty devices are generally used in manufacturing or industrial applications to gain accurate measurements under difficult conditions.

The refrigeration engineer and refrigeration technician work with a variety of refrigerant equipment and gases to perform tasks. Refrigerant equipment is sometimes called Heating, Ventilating, and Air Conditioning (HVAC) equipment. The equipment used is grouped into two main categories: refrigerant charging equipment and refrigerant recovery equipment.

Refrigerant charging equipment is used to charge a new refrigeration system or recharge an old system that has lost its ability to provide proper cooling function. This refrigerant equipment is usually very basic, consisting of a gauge, a valve, and a hose with a connector that fits onto the input port of the refrigeration system. The gauge set is attached to a tank that holds the refrigerant and the valve is opened to charge the system.

A compressor pump is a device used to compress a gas, commonly preparing the gas to be used at high pressure. Found on air conditioning (AC) and refrigeration units, one of the most common types of compressor pump is used on air compressors. Using one of three typical methods of compressing air or gas, the compressor pump is most commonly turned via a rubber drive belt with most units being powered by an electric motor. There are two common types of pump, the single and dual stage version.

When used to compress air, the compressor pump is used to pack the air into a holding tank to be used a later time or to be used in a high-pressure/high-volume application. While a compressor pump may contain several pistons, the most common type of compressor uses a single- or double-cylinder design. 

People who enjoy working with their hands, are mechanically inclined and naturally outgoing report the greatest satisfaction as an operating engineer. In this career, you will meet with other trades professionals, parts suppliers, and clients, or people impacted by the system. The ability to interact with others while communicating clearly and effectively is very important.