Heat, Ventilating and Air Conditioning (and Refrigeration) or in short, HVAC-R, systems are used for regulating the thermal comfort of buildings while also maintaining proper air quality by circulating and refreshing the indoor air with a fresh outdoor one. These systems control the overall air temperature in a place, the level of humidity as well as the movement of the air in order to keep the residents of a building healthy and comfortable.
2HVAC-R System Parts
A HVAC-R system consists of a variety of parts which keep the system properly running. Here are the basics of the main ones:
- Thermostat – This is usually the most visible part of a HVAC system as it is set on a prominent and easily accessible wall. It can be either set manually or programmed in advance in order to keep the home at the needed temperature. Once the temperature in the room becomes too hot or too cold, the thermostat triggers the coil-condensing unit combo or the heat exchanger to start circulating cooled or warmed air, depending on your preferences.
- Furnace – This is the key element in any HVAC system. It is also the largest one and it requires substantial space, usually in the attic, the cellar or a special closet which is designed specifically for that purpose. Its main function is heating a supply of air which will be later on distributed in different rooms through the HVAC system. The entire heating process is made possible with the help of one of the four possible heat sources – electric resistance, combustion (burning natural gas, coal, oil or propane), heat pump or solar energy collected on site.
- Heat Exchanger – This part is located inside the furnace unit’s housing and it works in a way that it switches on when the thermostat activates the furnace to produce warmer air in colder days. Consequently, the heat exchanger pulls in cold air, heats it up and then circulates the heated air through the ducts and out through the vents.
- Evaporator Coil – This element has an opposite role to the heat exchanger, meaning, it cools the air when your thermostat is set to lower temperatures in days when the temperatures are high. It is located in a metal enclosure on the exterior of the furnace, to the top or side. It operates similarly to an automobile radiator in order to produce cool air, which once produced, is then circulated through the ductwork.
- Condensing Unit – This part is connected to the evaporator coil and it is installed on the outside of the home by HVAC contractors. It is filled with refrigerant gas, which when it is being cooled to a liquid as a result of the hear exchange with the outside air, this condensing unit pumps the liquid to the evaporator coil in order for it to be evaporated to gas once again.
- Refrigerant lines – These are actually narrow tubes which carry the refrigerant substance which is transferred to the condensing unit and it is vaporized in the form of a gas. Then, they return it to the evaporator coil in liquid form. These “lines” are made from durable heat-and-cold-resistant metals, such as aluminum or copper.
- Ductwork – This refers to the entire system of ducts that transports the air that is cooled or warmed by the system to the different rooms in your home. The ducts are usually made out of a lightweight aluminum which is easy to install. Nevertheless, the ductwork can be also made from other materials, such as flexible plastic, steel, fiberglass, polyurethane or fabric.
- Vents – These are the rectangular outlets which are used to transfer the cooled or heated air from the duct system to the different rooms in your space. They are located either on or near the ceiling and are fronted with angled slats which direct the cooled/warmed air downwards to actually where people are using the room. These slats can be either entirely closed or manually operated in order to control the level of heating or cooling in the room to which it will be directed towards.
Monitoring these systems is of the utmost importance for achieving better performance as interior monitoring can provide valuable feedback in terms of getting an insight for correcting any inefficiencies and optimizing the equipment as well as for the sake of the overall system operations.
Furthermore, regular monitoring can also identify opportunities for possible energy efficiency upgrades as well as provide validation for improvements that contribute towards LEED certification.
The job of the mechanical contractors and building operators who oversee the performance of these systems is to ensure that the entire HVAC-R equipment runs efficiently so that there is a proper interior environment as well as in order to keep the operating costs at a reasonable level.
3Why you should be interested in a HVAC-R career?
In the modern world of today, HVACR systems are a great necessity for many reasons – medical health, personal comfort, food preservation, work productivity, water supply being among the most obvious ones. This industry is expected to produce thousands of new jobs in the following decades because the use of these products greatly expands as years go by.
4The duties of HVAC-R mechanics and installers
- Use blueprints or they design specifications to repair or install HVAC-R systems
- They install controls and electrical wiring and test whether they work properly
- Maintain and inspect their customers’ HVAC-R systems
- Connect systems to water and fuel supply lines, air ducts as well as other components
- Test separate components of the system to check whether they need any repairs
- Replace or repair the defective or already worn out parts
- Determine the energy use of the HVAC-R system and also make recommendations to improve the efficiency of the system
Despite the fact that most HVAC-R technicians are trained to maintain, install and repair HVAC-R systems, many of them focus their work either on maintenance, installation or repairs. Some specialize in either one or more specific aspects of these systems, such as radiant heating systems, balancing and testing, solar panels or commercial refrigeration.
There is a variety of tools used in the process of installation– screwdrivers, pipe cutters, wrenches as well as other basic tools. Technicians also use a wide array of other more sophisticated tools for installing or testing HVAC-R systems components, such as voltmeters, carbon monoxide testers, combustion analyzers as well as acetylene torches.
When installing or repairing HVAC-R systems, technicians must abide to the government regulations regarding the recovery, conservation and recycling of refrigerants. These regulations include the ones concerning the adequate handling and disposal of pressurized gases and fluids.
Many HVAC-R technicians sell service contracts, meaning, they provide their clients with regular maintenance of their heating and cooling systems. This usually implies replacing filters, cleaning ducts, and checking refrigerant levels. These technicians mostly work in schools, factories, office buildings, stores or residential homes.
Statistics show that in 2012, heating, air conditioning and refrigeration mechanics and installers held about 267,600 jobs. Sixty one per cent of them were employed in the plumbing, heating as well as the air-conditioning contractors industry, while about nine per cent were self-employed.
5HVAC-R Technician Skills
Customer-service skills – Since most of the time HVAC-R technicians work in either business offices or customers’ homes, it is of utmost importance that they are polite, friendly and punctual. Sometimes they will need to deal with unhappy customers whose air conditioning or heating is not working, so they need to know how to behave in such cases.
Physical strength –HVAC-R technicians may have to support and lift heavy equipment pieces and components, often times on their own without help, so it is very important that they have the strength to handle it.
Detail oriented – They need to carefully maintain and keep records of all the work they have performed. Their records need to include the type of work they performed and the time it took them to do it, as well as list specific equipment and parts they used for that purpose.
Mechanical skills – Since HVAC-R technicians install and work on complicated climate-control systems, they have to understand the different HVAC-R components and to be able to properly disassemble, assemble, and if needed, program them.
Troubleshooting skills – Heating, air conditioning, and refrigeration systems consist of many intricate parts. Therefore, in order to repair malfunctioning systems, HVAC-R technicians must be able to identify the particular problems and then determine the best way to repair them.
Time-management skills – Since these technicians oftentimes have numerous daily maintenance calls and problems they need to solve, they should keep a schedule and make sure to complete all necessary tasks or repairs right on time.
Regardless whether they have acquired their skills through postsecondary occupation or in some other way, HVAC-R technicians are obliged to take a couple different tests that will measure their skills. These tests vary according to the different levels of experience of individuals.
Therefore, the technicians who have a relevant coursework and experience less than 2 years should take the “entry-level” certification exam. The purpose of these tests is to establish the basic competency in light commercial heating and cooling, residential cooling and heating, and commercial refrigeration.
Technicians interested in pursuing a career in the field can take the exams at trade and technical schools.
Technicians who already have at least one year of installation experience and two years of repair and maintenance experience, can take a variety of specialized exams.
These exams are crucial for certifying their competency in working with certain types of equipment, like compressed-refrigerant cooling systems or oil-burning furnaces. Certifications can be quite helpful as they pose as evidence that the technician has certain competencies. Although the specific requirements for license vary in different states, all candidates must pass an exam.
Additionally, the U.S. Environmental Protection Agency (EPA) requires all technicians who work with or buy refrigerants to have certificates that they are capable of proper refrigerant handling.
In order to get their certificate, technicians must pass a written exam which is specific to one of the three specializations: Type I – servicing small appliances; Type II – high-pressure refrigerants; Type III – low pressure refrigerants.
Many trade schools and employer associations offer training programs that are designed to prepare students for the EPA exam.