The A/C system is a device that allows us to maintain our environment at our desired temperature. The system is so common we can feel its effect wherever we go.
It can be installed in our homes, workplaces, cars, and maybe even newer religious institutions. In other words, it can be used in both residential and commercial settings. Aircon, AC, and A/C are many other words used to convey air conditioning.
It consists of a fan, which blows the conditioned air within the space. The conditioned space can be a structure or vehicle. Today, we want to discuss the definition, diagram, purpose, components, types and the basic principle of operation of the air conditioning system.
So let’s get started.
What is Air Conditioning System?
An air conditioner cools a space by removing heat from it and displacing it to some outside area. The cool air can then be distributed throughout a building by some form of ventilation.
Air conditioners have some work input to operate because the Second law of thermodynamics forbids decreases in entropy on their own. Air conditioners function like a heat pump, but traverse a cooling cycle.
To cool, a refrigerant substance goes through the following steps:
- A cold refrigerant absorbs heat from a hotter room in the evaporator, cooling the room down.
- The refrigerant changes into a gas and is put into a compressor to raise the temperature.
- Refrigerant passes through the condenser coils, extracting heat to the outside air.
- Refrigerant expands and drops pressure to cool the refrigerant back down below room temperature so that the cycle can happen again.
Air conditioning represents one of the elements in an HVAC system that provides temperature control in your home to optimize comfort and liveability in a space.
Air conditioners are called “split-systems” because of their outdoor unit (the condenser) and an indoor unit (the evaporator) component working together to provide cooling capability of interior spaces while also dehumidifying the air.
Dehumidification occurs as air from the home is drawn over the evaporator (which will be cold), condensing the warm air, and losing moisture (like a glass of lemonade on a warm day).
The “split-systems” refer to the combination of outdoor and indoor components working together, but there is another type, where the indoor and outdoor systems are combined into one system, referring to as a “packaged” system.
Components of Air Conditioner System
Here are components of a commercial air conditioning system:
#1. Compressor.
The compressor is the system’s engine because it works with a fluid that easily converts gas to liquid. It converts low-pressure gas into high-pressure gas, commonly with a high temperature.
To get a compressor to operate, a generated energized gas will reduce the gap regions between molecules. The compressor then releases the energized gas, referred to as a refrigerant, to the condenser.
#2. Condenser.
The condenser is the outdoor part of a heat pump or air conditioner and during summer will release heat or absorb heat from the inside of the structure. The condensers in heat pumps and split air conditioners have essentially the same components.
#3. Condenser Coil.
The condenser coil has a fan which cools the gas while the high-pressure gas is converted to a liquid.
The liquid obtained will be used by the evaporator to perform the work. The condenser and compressor are placed outside of the house.
#4. Thermostat.
The thermostat controls the heat energy, either inside or outside of an air conditioning system to maintain the temperature of the system. Thermostat options, depending on design, may have a manual or automatic setting.
#5. Evaporator.
In an HVAC system, evaporators are located in the home near a boiler or furnace and are connected to the condenser with a very thin line/piping.
In the A/C, the high-pressure gas converts into low-pressure liquid and due to the drop in pressure, the liquid converts into a gas. It is the fluid (refrigerant) that provides cooling and absorbs heat out of the system.
The evaporator turns the fluid to a gas for the compressor to compress. This all takes place in a cyclical fashion.
#6. Air Handler and Blowing Unit.
In an A/C, these components work together to move cool air around the room and to also pull air through the evaporator. Air flows freely around the room via the air duct system.
#7. Fan.
The fan is the indoor air handler of an AC. The fan pushes the warm air in your home back to the condenser.
That recirculated air travels to the air handler to be treated to be cool again and will circulate around your duct and vent system throughout your home.
#8. Filter.
The HVAC filter plays an important part in the programmable heating & cooling device in your home.
The HVAC filter removes small particles, such as dust, pollen, dander, and other contaminates from the air you and your family breath.
The air filter captures those particles so that they don’t get recirculated again.
How Does a Air Conditioner Work?
Now that you understand what air conditioner parts look like. Let’s get a little more into detail about how the whole process works.
The thermostat senses and controls the temperature of the air in the house. It is usually mounted on a wall in the center of the house.
Once it senses the need to lower the air temperature, it signals the indoor and outdoor components of the air conditioning system to go to work.
The fan on the inside unit pulls hot air through return air ducts from the home. This hot air moves through filters that catch dust, lint, and other particulates in the air. After the heated air is filtered, it moves over a cold evaporator coil.
As liquid refrigerant passes through the evaporator coil, it absorbs heat from the air passing over it and changes to gas. The blown fan of the inside unit then pushes the cool air back through the deliver air duct work of the house to different parts of the home.
The refrigerant gas leaves the house through a copper tube and enters the compressor of the outdoor unit.
Think of the compressor as a big electric pump. The compressor pressurizes the refrigerant gas then sends it to the condenser coil of the outdoor unit.
The condenser coil has a fan that pulls outside air through it, absorbing and dissipating heat from the home.
During this process, the refrigerant changes back to the liquid refrigerant. Then it goes back to the indoor unit through copper tubing and goes through an expansion device to metered state before it goes into the evaporator coil again.
Each cycle, as the refrigerant cools, it absorbs more heat from the air again and starts all over.
Functions of Air Conditioning System
Here are the main functions of air conditioning in homes today:
- The purpose of air conditioning is to create a comfortable environment for people.
- Special types of conditioning systems will cool electrical devices.
- It removes humidity. All air has humidity ranging from 30 to 65%, while ideal temperature 20 – 26 degrees Celsius.
- The air conditioning system is dealing with room air which people would be comfortable with while not decreasing productivity.
- Air quality can be affected by temperature, pressure, and humidity. Air pressure does not change.
- An air conditioning system will likely affect heating, dehumidification, cooling, and humidification functions.
Classification of Air Conditioner System
Air conditioning systems are classified to differentiate one type from another. This serves as the basis for choosing the applicable air conditioning system for the building. There are three sub-categories of air conditioners:
Classification bases on major function:
- Comfort air conditioning: hotels, homes, offices, etc.
- Commercial air conditioning: malls, supermarkets, etc.
- Industrial air-conditioning: processing, laboratories, etc.
Classification basis on the season in the year:
- The summer air conditioner is a cooling device that controls all four atmospheric conditions for comfort during the summer months.
- The winter air conditioner provides warmth and comfort during the cold months.
- A year-round air conditioner usually consists of both a heating and a cooling system and is controlled automatically. The temperature can comfortably remain indoors in winter or summer conditions.
Types of Air Conditioners
#1. Central Air Conditioning
A central air-conditioning system is the largest and most expensive type of traditional air conditioner. A central air-conditioning system has two types of equipment – the condensing unit and evaporative unit – connected by refrigerant tubing.
The condensing unit is a large outdoor appliance that contains the compressor, condensing coils, and condensing fan. The evaporative unit is generally located in the plenum (the large central chamber between the furnace and duct system) of your furnace. That means the air conditioning system uses the same ducts and blower fan as your heating system.
The evaporative unit consists of the evaporator coil and expansion valve. Condensed moisture on the evaporator coils typically drains away through a tube to a floor drain.
If installing a new central air-conditioning system, the most important aspect is that the system is properly sized for your home. If the system is too large it will struggle to perform well and not adequately dehumidify the interior air. If the system is too small, it won’t cool sufficiently.
Proper maintenance of a central air-conditioning system is also necessary, and often requires a professional.
#2. Window Air Conditioners.
Technically, a window air conditioner is called a “unitary” air-conditioning system, consisting of a self-contained air-conditioning unit placed in a window or, less often, through a hole in an exterior wall.
A window air conditioner has all the refrigeration components in a single compact box. It ejects heat through the condenser coils on the outside and uses the evaporator coils to blow cooled air inside.
Room moisture that condenses on the evaporator coils will drip to the ground from an evaporator tray on the bottom of the appliance. The window air conditioner must be propped to slightly tilt toward the outdoor side.
If tilted on the interior side, some air conditioners may drip water onto the inside floor of the house. Window air conditioners come in a variety of sizes that can cool any space from a single room and up to an entire floor.
A large window air conditioner may even be enough to cool an entire small home or single-story home. It is an economical choice between installation and use.
#3. Portable Air Conditioners.
A portable air conditioner is a floor unit that vents exhaust heat to the outside through a hose. Like window units, all the coils are housed in one box and therefore they tend to be a noisier option.
Portable Air conditioners are a good option for temporary cooling in spaces of less than 500 square feet, where they can be inexpensive and take the place of a window unit. A portable air conditioner may even have a reservoir for the water that is created while cooling the space, if it does, it will require emptying periodically.
#4. Ductless Mini Split Air Conditioners.
Ductless, or “mini-split,” systems have two units. There is an exterior unit – the condensing unit (compressor and fan), and an interior unit that cools air and circulates air in the house. While this evaporator unit typically mounts high on a wall, the refrigerant charge travels through tubing in the wall.
This system can be a good option for homes that do not have an HVAC system, and is still often less expensive than a full HVAC system. Many versions of ductless systems also provide heating too.
#5. Floor-Mounted Air Conditioner.
Floor-mounted air conditioners, also known as through-the-wall air conditioners or split systems, are units that are placed on or nearby the floor. A floor mounted air conditioner typically mounts low on the wall and can be partially recessed.
A floor mounted air conditioner is very easy to service and maintain due to its low mounting position and is a simple unit since it works which like other air conditioning units, except it is mounted to quickly cool down the room.
#6. Smart Air Conditioner.
Smart air conditioners allow you to set and control temperatures you desire in the comforts of your own home. You are able to create a custom cooling schedule that guarantees that your house is at the desired temperature every hour of the day or night.
Smart air conditioners save money over time because, once set to a desired temperature, they then efficiently operate to keep the temperature you want. This means they use less energy than a standard AC system, which lowers your bill.
Smart air conditioners connect via Wi-Fi and have an app that allows you to check the system and adjust the temperature when you aren’t home. In addition, smart air conditioner models have other energy efficiency capabilities, such as geofencing (sets the temperature based on your location), energy monitoring, and service alerts.
#7. Geothermal Air Conditioner.
The geothermal HVAC system transfers heat. The system consists of two components in your home: a heat pump and a pipe buried in the ground. The heat pump circulates a fluid mixture that serves as a heat exchanger to absorb or extract heat for warming or cooling your home.
As an air conditioner, the heat pump pulls heat out of your home and into the ground to cool your home. The ground acts as a heat sink in the summer to keep your home cooled.
#8. Dual-Fuel Air Conditioner.
Also called a dual-fuel HVAC system, this system uses two sources of fuel to heat and cool a house. A dual-fuel combination would include an electric heat pump and a gas furnace, or an electric heat pump and an oil furnace. Essentially, the heat pump does the same job as your central air conditioning system.
In the summer, the heat pump operates as an air conditioning unit. The heat pump removes hot air from inside and distributes cooler air from the furnace’s blower. In the cooler months, the heat pump is the main source of heat until the air gets very cold and your furnace triggers to come on.
This combination works well especially for rural homes. Homes that lack access to natural gas and have limited access to propane or oil are best served by this system.
#9. Evaporative Air Conditioner.
Evaporative air conditioners – also known as evaporative coolers or swamp coolers – work on an easy concept of cooling air with the evaporation of water. They can be purchased commercially as portable units or made as a small DIY unit, and they are popular in hot, dry parts of the southwestern United States such as Arizona and New Mexico.
The operation of this device relies on a continuous movement of fresh, warm and dry air passing through a wet, internal filter and chilled air is blown into a room with a fan and motor. An evaporative cooler works best with the windows open.
Modern evaporative air conditioners come as whole house systems or individual units, but it’s unlikely and inefficient to have an evaporative cooler and conventional air conditioner interacting in the same house.
#10. Built-In Wall Air Conditioners.
A built-in wall AC unit, also known as a ductless or split system AC, has a low profile and pleasing aesthetic properties, combining design and function. They contain the condenser and compressor in the built-in wall AC unit, which is located on the outside, and an evaporator that resides inside the built-in wall air conditioning unit to cool the inside.
A built-in wall AC unit is different than a window-mounted AC unit due to where each will be installed. A built-in wall air conditioning unit can be installed directly to a wall’s exterior or in a custom hole in the wall and window-mounted air conditioners are designed for standard window frames.
#11. Variable-Speed Air Conditioners.
Variable-speed air conditioners are a type of cooling service that can run at different speeds according to the cooling needs of a particular home. Unlike standard air conditioners, which can only be fully on or off, some units can be partially on while achieve the target temperature.
Variable-speed air conditioners are considerably more energy efficient than other types of ACs, because they can be implemented based on the specifications of a house. Lastly, variable-speed AC units are quieter and remove more humidity from the room than other types of ACs during cooling.
Advantages of Air Conditioning System
Air conditioning not only enhances comfort but also offers health advantages. This article discusses the benefits of air conditioning.
#1. Reduces the Possibility Of an Asthma Attack.
Many of us don’t realize that air conditioning can reduce allergens and thus lower the risk of an asthma attack. An air conditioner can lower the amount of dust mites, pollen, mold, mildew, and airborne allergens that can trigger asthma.
Air exposure is a leading factor pertaining to asthma symptoms, respiratory problems, and an allergic response. Make sure your filters are replaced frequently, at least every two weeks.
#2. It Saves Life.
According to the focus on health report by the Environmental Protection Agency, more than 9,000 people die per year related to heat in the United States. It is even more serious when heat contributes to many more deaths without heat being the primary factor.
Without a doubt, a working air conditioner could also prevent heat stress-related illnesses and deaths in homes and workplaces. An air conditioner could really save your life!
#3. Better Air Quality.
Installing air conditioning is yet another excellent reason to relax. Poorly ventilated and overheated indoor air is laden with dust and bacteria that are harmful to your health.
Symptoms can include headaches, fever, fatigue, coughs, and colds. A single air conditioning unit can significantly improve indoor air quality and create a much healthier space.
Air conditioners have the unique ability to remove dust, bacteria, and pollen from your environment.
#4. Controls Humidity.
Hot summer days that are humid becomes uncomfortably sticky. High humidity is nothing new for Australians but is bad for your health. The best humidity is between 30% and 50%.
While you can’t do much about outdoor humidity, selecting an air conditioner could substantially reduce your indoor humidity. You can’t even use ceiling or pedestal fans in the hot and humid weather, even semi-naked is somewhat ineffective.
Instead of paying for dehumidifiers, buy an air conditioner that has more benefits.
#5. Improves Sleep.
This air conditioner benefit is vital because sleep is essential for your physical and mental fitness.
Sleeping conditions can be bad due to hot summer weather and can create a host of health problems. Studies show that an air conditioner can help to improve sleeping conditions for a variety of reasons.
Because your body requires cooling prior to going to sleep, as hot rooms raise your core temperature. An air conditioner service can provide your body the perfect temperature to cool down.
#6. Prevents Your Devices from Overheating.
Your electronic devices are also at great risk of overheating and can be very detrimental to them besides human health and mental health.
Many household appliances, such as toasters and microwaves; even cell phones can be damaged by heat. By investing in an air conditioning service, you will not only help to benefit your health but also your electrical devices.
#7. Reduces Insects and Parasites.
Everyday people are seeking any device, method, or spell for stopping mosquito bites, invasions, and house flies.
Few people know this, but your air conditioning can decrease the number of insects and parasites. These pesky creatures not only should be an annoyance to deal with, but they can also carry disease.
Disadvantages of Air Conditioning System
Air conditioning does have some disadvantages even though it has many benefits.
#1. Expensive Energy Bill.
The average household uses 40 percent of all energy to heat or cool their homes. It’s safe to say that the cost of energy will rise because an air conditioning system requires energy to maintain a comfortable temperature. You can always purchase an energy efficient air conditioning system.
#2. Skin Dryness.
Because the air conditioning system takes away humidity in the air, if you spend too long inside, your skin will start losing moisture.
It can cause skin sensitivity or dryness. When this happens, use a moisturizer.
#3. Environmental Hazards.
It’s sad to think that while air conditioners help make our lives feel more comfortable, they can also harm the environment and release harmful gases.
Studies have estimated that by the year 2050 air conditioning will factor in about 25 percent of the world’s carbon footprint.
#4. Aggravated Flu, Cold, and Sinus Symptoms.
Flu or common cold symptoms like fever, sore throat, nasal congestion, and cough can also be exacerbated by an air conditioning system.
This is due to the fact that when the air conditioner blows the dry air into the room, the membranes in your mouth and throat will dry up and become irritated.
#5. Respiratory Issues.
The benefits of using an air conditioning system are many, it will reduce the number of allergens in the air. However, over time the filters in the AC can become dirty and clogged.
In poorly maintained air conditioning systems that are not cleaned at least once every two weeks, airs can circulate dangerous dust and particles eventually resulting in breathing difficulties.
It is important to understand that almost all of the health risks of the air conditioning system can be minimized by periodically cleaning the filters.