Intro To HVAC: Chapter 1
Evolution of HVAC Systems
In this module, we will go through the history of HVAC(R) systems and compare how it has changed over the years. Skip to quiz!
Define HVAC(R)
We use different systems to heat and cool our home. These systems are known as HVAC(R) systems.
HVAC(R) stands for
H - Heating Systems
V - Ventilation Systems
AC - Air Conditioning Systems
R - Refrigeration Systems
These systems work together to provide us a healthy and comfortable lifestyle.
Brief History of HVAC(R) Systems
The HVAC systems used earlier were not as effective as they are today. They have changed a lot since then. Now, we will take a look at how people in the past have brought heating, cooling, and ventilation into their homes.
Ancient Greek civilizations started to use central heating to warm their homes. To do this, they built a basement in their homes to keep fires lit. Hot air rises, so the heat generated in the basement would circulate throughout the home.
In the past, people built houses with high ceilings and multiple windows to circulate air. This led to the invention of ductwork, which was used to distribute air throughout the home. This has been a lasting feature that we still use ductwork in our current systems.
An example of an early AC system comes from the Chinese. The Chinese discovered that moving air on the skin creates a temporary cooling effect. So, they invented fans operated by hand.
To keep food cool, early Greeks and Romans covered storage pits with snow and tree branches. The storage pits act like a natural cooler in the ground. So it preserved food for a few days without food spoiling.
Shortfalls of Previous HVAC(R) Systems
Even though our ancestors were creative with their tools, there were shortfalls to the previous heating and cooling systems.
The ancient Greeks did not have an efficient heating system. People used to burn 5 kilograms of wood to heat a house. Now, the same house requires fewer resources, because just 1 kilogram of natural gas or oil can heat the home.
Previous ventilation systems were heat-driven, so people in the past used the idea of hot air rising to circulate air. But the problem with this is that it is dependent on the season because we would not want to circulate hot air in the summer. There were no modern fans or blowers to help circulate the air.
Before modern air conditioners, people would have to use hand-operated fans to make cool air. This requires human effort. Moderns fans can use electricity to power the movement of air without human effort.
The ancient Greeks and Romans used to keep food cold using storage pits covered with snow.
The problem was that if temperatures surrounding the storage pit were high, then the snow would melt and not keep food cool. Modern refrigerators are not affected by surrounding temperatures.
Modern HVAC Systems
The shortfalls of traditional HVAC systems hinder providing a healthy and comfortable lifestyle. So, modern HVAC systems have evolved a lot to resolve shortfalls of the traditional HVAC systems.
The overall goals of any modern HVAC system are to provide:
Temperature control,
Fresh air circulation,
Air filtration, and
Efficient heating and cooling.
Let us discuss each of them in detail.
Modern cooling systems have precise temperature control. For example, when the thermostat senses the air temperature rising above 72℉, it turns on the AC. This will start cooling the air in our home. As the thermostat senses that the air is cooled below 72℉, it turns off the AC.
Modern ventilation systems can improve air quality by constantly bringing in fresh outdoor air into a room. Filters are used to remove dust and dirt particles. This makes our air cleaner.
Modern HVAC systems also include both cooling and heating systems in one unit. This can save construction space and the use of power. For example, you would save space by not needing a separate fireplace to heat your home.
HVAC systems used earlier were not as effective as they are today. HVAC systems evolved a lot to resolve shortfalls of the traditional systems.
Importance of HVAC Systems
In this module, we will talk about different types of HVAC(R) systems. We will also discuss their importance. Skip to quiz!
HVAC(R) Systems
Modern advancements in HVAC(R) systems have allowed us to live an improved lifestyle. Let us take a look at the types of modern HVAC systems.
Heating systems are used to provide warm air in our homes when we experience cold temperatures. Furnaces are an example of heating systems.
Now, along with a heating system, we also require a ventilation system to bring in fresh air and circulate it. Fans and blowers are examples of a ventilation system.
We generally open windows for fresh air, but this can bring in unwanted cold or hot winds. Ventilation can help maintain normal temperatures inside while also removing stale air.
Unlike heating systems, the purpose of an air conditioning system is to cool our home during the hot summers. For example, a window air conditioner maintains cool temperatures in a specific room.
Recall that modern HVAC systems also include both cooling and heating systems in one unit. A heat pump is an example of such a system. In warmer months, it acts as an air conditioning system, while in cooler months, it reverses the process and acts as a heating system.
Much like an air conditioning system, the purpose of the refrigeration system is to provide cooling. We use an air conditioning system for human comfort. Whereas, a refrigeration system is used to store perishable food items for a longer time.
Refrigeration is often used to keep foods or medicines from spoiling. This is because bacterial growth slows at lower temperatures. A refrigerator is an example of a refrigeration system.
Many other HVAC systems can also provide heating or cooling to larger residential spaces. Some of them are:
Ductless mini-split system, and
Packaged rooftop unit
We rarely use packaged rooftop units for heating and cooling house.
The Importance of HVAC(R) Systems
HVAC(R) systems are important because they provide modern conveniences in our life. For example, heating systems help us maintain warm temperatures during the winter. On the other hand, air conditioning provides cool air on hot summer days.
The HVAC(R) systems also work together to ensure we lead healthy lives. Ventilation systems provide clean air and remove unwanted smells. Ventilation also removes carbon dioxide and brings in fresh oxygen for people to breathe.
A refrigeration system helps to store food, medicine, and chemicals at cool temperatures. For example, food can be kept at temperatures around 0° F or –18° C for months without decay.
Modern advancements in HVAC(R) systems have allowed us to live an improved lifestyle. Heating and AC systems help bring hot or cold air into the home depending on the time of year.
Ventilation systems help to circulate the needed hot or cold air. Refrigeration systems help us store food for months without decay.
HVAC Industry
In this module, we will describe the different job opportunities in the HVAC(R) industry. We will also talk about different associations related to HVAC regulations and standards. Skip to quiz!
Job Opportunities
There are a lot of job opportunities within the HVAC industry. There is a need for people to install and maintain HVAC systems. In addition, we need managers to oversee projects and communicate with clients.
The different roles in the HVAC industry include:
Air Conditioning Technician,
Refrigeration Technician,
HVAC Engineer,
HVAC Installer,
Project Manager, and
Service Manager
An HVAC technician works on heating, air conditioning, and refrigeration systems. They will work on the following:
Installation
Repairs, and
Applying local codes and regulations
An air conditioning technician is responsible for making sure the AC unit in homes and offices is working correctly. They need to be able to:
Fix electrical components,
Maintain motors, and
Check the ductwork
Refrigeration technicians are also known as refrigeration mechanics. They are responsible for installing, maintaining, and repairing refrigerators. For example, they repair things such as ice cream machines and refrigeration units.
HVAC engineers are responsible for designing HVAC systems. They also need to know how to repair and maintain systems within HVAC. This is important so that they can properly design HVAC systems.
An HVAC installer is responsible for installing all required components into a space or building. The installer should be
physically strong,
able to read blueprints, and
good at time management
Unlike the HVAC installer, the project manager is not involved with the installation of units. They oversee new projects for HVAC construction. The project manager communicates with the client throughout the project.
Similar to an HVAC project manager, the service manager oversees projects. The service manager will assign specific jobs to technicians and oversee their work. A service manager should have strong management and communication skills.
HVAC Salaries and Career Growth
The general average salary for college graduates in the USA is about $50,000. The average plumber salary in the USA is $55,656 per year average whereas, a mechanic can earn up to $52,634 per year. An average HVAC technician can make more than these trades.
HVAC technician make about $60,513 per year in the USA. Although, the salary of an HVAC technician varies as per experience. Entry-level positions start at $37,047 per year, while most experienced workers make up to $99,846 per year.
The average salary of an HVAC technician is very likely to increase. There are going to be increased job opportunities in the HVAC industry. HVAC industries are estimated to see a 13% growth in jobs by 2028.
The demand for HVAC workers is growing. A lot of people currently working in HVAC are retiring. The problem is that there are not enough HVAC skilled technicians to fill the place of retired technicians.
People do not go into HVAC because they think the job does not pay well. Students choose to go to college instead of HVAC trade schools. However, the HVAC industry is growing, and there are many high-paying job opportunities for qualified people.
The EPA
The Environmental Protection Agency (EPA) was formed as a result of environmental concerns. The EPA is focused on protecting human health and the environment. Due to an increased demand for HVAC systems, it is important for us to regulate the manufacturing and disposal of chemicals.
Section 608 of the EPA regulations are focused on environmental safety and technician safety. The technician must be certified to
Maintain,
Repair, and
Dispose of HVAC equipment.
AHRI
The Air Conditioning, Heating, and Refrigeration Institute (AHRI) develops standards for HVAC systems. The standards are important because they are used to evaluate and certify HVAC equipment. An example of a standard that the AHRI sets for HVAC systems are with air filter equipment.
AHRI Standard 680 ensures that every HVAC system can effectively remove a certain amount of particles, such as dust, from the air. The standard helps improve the quality of indoor air. This allows us to breathe cleaner air in our homes and workplaces.
ASHRAE
The ASHRAE is another association which develops standards for HVAC systems. ASHRAE stands for American Society of Heating, Refrigeration, and Air Conditioning Engineers.
The standards published by ASHRAE are used in building regulations and codes. For example, standard 62.1 specifies the minimum ventilation rate for new and existing buildings. The minimum ventilation rate ensures that the indoor air quality is clean so that people do not get sick.
Other Organizations
Other organizations provide specific services for HVAC technicians. For example, there is:
American Air Conditioning Contractors of America (ACCA), and
Refrigeration Service Engineers Society (RSES)
The American Conditioning Contractors of America (ACCA) provides contracting services for HVAC technicians. The ACCA helps HVAC technicians find potential clients. This helps technicians build their network connections and find more jobs.
The Refrigeration Service Engineers Society (RSES) offers several certifications for HVAC technicians. These certifications can help build an HVAC technician’s knowledge and skills. In addition, the certifications make them more marketable, so they have more access to job opportunities.
There are job opportunities within the HVAC industry, such as:
Air Conditioning Technician
Refrigeration Technician
HVAC Engineer
HVAC Installer
Project Manager
Service Manager
There is growth potential in the HVAC industry and likely an increase in the average salary for workers.
There are trade associations, which set standards for HVAC equipment. The standards are meant to keep people safe within their homes and ensure that we dispose of materials properly. Other organizations for HVAC technicians can help them find clients and get certification training.
Question #1: HVAC(R) stands for?
Heating, Vans, Air Conditioning, Refrigeration
Heating, Ventilation, All Cooling, Refrigeration
Heating, Ventilation, Air Conditioning, Radio
Heating, Ventilation, Air Conditioning, Refrigeration
Scroll down for the answer...
Answer: Heating, Ventilation, Air Conditioning, Refrigeration
HVAC(R) stands for:
H - Heating Systems
V - Ventilation Systems
AC - Air Conditioning Systems
R - Refrigeration Systems
Question #2: Which of the following is an example of a previous HVAC(R) system?
People built houses with no windows to circulate air.
Humans made hand-operated fans to cool themselves.
Early Greeks stored their food in the ocean to cool beverages.
Early Romans used paper to cook food.
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Answer: Humans made hand-operated fans to cool themselves.
The Chinese made hand-operated fans to cool themselves. This was the beginning of our AC systems.
Question #3: What was a shortfall of previous refrigeration systems?
The storage pits were affected by the surrounding temperatures.
The storage pits were not affected by the surrounding temperatures.
The storage pits had too much salt.
The storage pits were too big.
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Answer: The storage pits were affected by the surrounding temperatures.
Previous refrigeration systems were affected by the surrounding temperatures. The storage pits were covered in snow. If surrounding temperatures were high, it would cause the snow to melt and not keep food cool.
Question #4:Which of the following is not a goal of an HVAC system?
Generating Electricity
Temperature Control
Fresh Air Circulation
Air Filtration
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Answer: Generating Electricity
The goals of a modern HVAC system are:
Control temperature, Fresh air circulation, Air filtration, and Improve efficiency
Question #5: What is an advantage of modern HVAC(R) systems?
We cannot control the temperature.
We need to use a lot of space and power.
We bring in the dirty outside air filled with dirt into our homes.
Filters are used to remove the dirt and dust to bring fresh air into our homes.
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Answer: Filters are used to remove the dirt and dust to bring fresh air into our homes.
An advantage of modern HVAC(R) systems is improved air quality. Filters remove dirt and dust from the outdoor air. This brings fresh air into our homes.
Question #6: Heating systems are used to provide cool air in our homes when we experience warm temperatures.
True
False
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Answer: False
Heating systems are used to provide warm air in our homes when we experience cold temperatures.
Question #7: What is an example of a ventilation system?
Air conditioners
Furnace
Fans
Heat pumps
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Answer: Fans
Fans are an example of a ventilation system. Furnace and pumps are an example of heating systems.
Question #8: Which of the following explains the function of air conditioning systems?
Air conditioning warms your home during the cold winters.
Air conditioning cools your home during the hot summers.
Air conditioning brings in a constant supply of fresh air.
Air conditioning circulates warm air.
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Answer: Air conditioning cools your home during the hot summers.
Air conditioning cools your home during the hot summers.
Question #9: Which of the following system can provide both heating and cooling?
Window AC
Heat Pump
Ductless Mini Split
Refrigerator
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Answer: Heat Pump
In warmer months, the heat pump acts as an air conditioning system and provides cooling. During the colder months, it reverses the process and acts as a heating system.
Question #10: Refrigeration is often used to keep foods or medicines from spoiling because bacterial growth slows at lower temperatures?
True
False
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Answer: True
Refrigeration is often used to keep foods or medicines from spoiling. This is because bacterial growth is slowed at lower temperatures.
Question #11: A _________ system is very similar to a Split AC system, except it has a reversing valve and can both heat and cool the air inside.
Central Air System
Window AC
Ductless Mini Split
Packaged Unit
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Answer: Ductless Mini Split
A ductless mini-split system can be used for both heating and cooling our home.
Question #12: Which of the following component of the split air conditioner is located inside our home?
Compressor
Evaporator Coil
Compressor Fan
Refrigerant
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Answer: Evaporator Coil
In a split air conditioning system, an evaporator coil is located inside our home to provide cool air.
Question #13: In which of the following situations would a packaged unit be useful?
If there is no space in the home for an AC unit
For a lower cost solution
It's only useful for heating, never for cooling
In none of these situations.
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Answer: If there is no space in the home for an AC unit
In rare cases, a packaged unit is installed on the roof of our home or building. It is useful if there is no space in the home for an AC unit.
Question #14: What's the difference between a packaged unit and a rooftop unit?
A packaged unit is located on the ground, not on a roof.
A rooftop unit is typically a ductless mini split unit.
A rooftop unit is considered a split system central AC unit.
There is no difference.
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Answer: There is no difference.
A packaged unit is also called a rooftop unit because it is generally installed on the roof of the building.
Question #15: Which of the following statements is true?
Heating systems warm the air inside a room during the winter.
Ventilation systems help to store food, medicine and chemicals at cool temperatures.
Air conditioners bring in fresh oxygen for people to breathe.
Refrigerators remove unwanted smells in a room.
Scroll down for the answer...
Answer: Heating systems warm the air inside a room during the winter.
Heating systems are important because they warm the air inside a room during the winter season.
Question #16: An air conditioning technician is responsible for making sure the refrigeration system is installed properly in offices and homes?
True
False
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Answer: False
False. An air conditioning technician is responsible for making sure the AC unit in homes and offices is working properly.
Question #17: Which of the following does not describe an HVAC installer?
Able to read blueprints
Great time management
Physically strong
Good sense of smell
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Answer: Good sense of smell
Good sense of smell. An HVAC installer should be physically strong, able to read blueprints, and have great time management.
Question #18: What is a skill that a service manager and project manager should both have?
Strong communication skills
Poor communication skills
Strong athletic ability
Weak athletic ability
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Answer: Strong communication skills
Project managers and service managers should have strong communication skills. Both need to communicate well with clients and technicians.
Question #19: Why is there an increased demand for workers in the HVAC field?
People do not care about global warming.
Everyone wants to go to HVAC trade skills instead of college.
A lot of people currently working in HVAC are retiring.
People do not want money.
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Answer: A lot of people currently working in HVAC are retiring.
There is a high demand for workers in the HVAC field because many current workers are retiring.
Question #20: A section 608 certification is required for anyone that is maintaining, repairing, and disposing of HVAC systems?
True
False
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Answer: True.
True. Anyone who is maintaining, repairing, and disposing of HVAC systems should have a section 608 certification.
Question #21: Which of the following best describes the purpose of the AHRI?
AHRI helps to deliver HVAC systems right to your homes.
AHRI is a school for future HVAC technicians.
AHRI helps install HVAC systems in your home.
AHRI develops standards for evaluating and certifying HVAC systems.
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Answer: AHRI develops standards for evaluating and certifying HVAC systems.
The Air Conditioning, Heating, and Refrigeration Institute (AHRI) function as a trade association is to develop standards for evaluating and certifying HVAC systems.
Question #22: Which of the following best describes how ASHRAE is similar to the AHRI?
They both set standards for HVAC systems.
They are both retirement services for HVAC technicians.
They are both associations for teachers.
They are both schools for HVAC technicians.
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Answer: They both set standards for HVAC systems.
ASHRAE and AHRI are both associations that set standards for HVAC systems.
Question #23: Which of the following is NOT a benefit of organizations, such as ACCA and RSES, for HVAC technicians?
The organizations install HVAC systems in the homes of technicians.
The organizations provide certifications for HVAC techs.
The organizations help HVAC techs find potential clients.
The organizations can help HVAC techs build their network.
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Answer: The organizations install HVAC systems in the homes of technicians.
Organizations, such as ACCA and RSES, do not help install HVAC systems into their homes.