Air conditioner types & how they work

There are many great types of air conditioners available, but choosing the right option comes down to whichever best suits your family’s needs, living space and budget. The most common residential cooling options include:

Central AC
systems

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Ductless
units

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Portable air conditioners

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Window air conditioners

Central Air Conditioners

What is Central Air Conditioning?
The most common way to cool a home is with a central air conditioning system. The system includes an external condenser unit which sits outside your home and expels heat as well as an evaporator coil, which generally sits above your furnace and cools the air within your home. Finally your furnace or air handle work with your AC using the fan to blow the chilled air through your home’s duct work. As a central air conditioner is integrated with your furnace system, it can take advantage of the furnace filter and any additional air purifying equipment you have added. This helps to clean the air throughout your home.

How Does Central Air Conditioning Work?
A central air conditioner works by using your furnace or air handler fan to draw warm air in through your home’s duct work. As the air is blown across the evaporator coil, which generally sits above your furnace, heat is removed from the air, cooling it down. The removed heat is absorbed into refrigerant running through the coil. This refrigerant is then pumped to the condenser, which is the part of your air conditioner that is outside of your home. The condenser expels this heat into the outside air, cooling the refrigerant, which is then sent back inside the home, to start the process over again.

Central AC Explained In 8 Steps

1. As the temperature in your house rises beyond what you set on your thermostat, a signal is automatically sent from your thermostat to the circuit board in your furnace
2. This tells the system that cold air is needed and turns on both the blower motor inside your house and the condenser, which sits outside your home.
3. Warm air is then drawn into your ductwork and cooled as it passes over the evaporator coil above your furnace
4. This cooled air is then returned to the home through the return air vents
5. Meanwhile refrigerant in your air conditioner absorbs the heat from the air as it flows through the evaporator coil
6. This heated refrigerant is then pumped to the condenser or outside portion of your air conditioner.
7. The condenser blows outside air across a different set of coils, which removes the heat from your home that was absorbed by the refrigerant, before the refrigerant is sent back into the home.
8. This process continues until the desired set temperature is met.

What are the benefits of Central Air Conditioning?
Central air conditioners provide cooling to all rooms in the home, not just to select rooms. They also tend to be a more cost effective solution to ductless ACs.

Central Air Conditioning Benefits When Used With Smart Thermostat

• Control your air conditioner from your mobile device
• It learns your preferences and builds a schedule for you
• Potential savings on your monthly energy bills

What Are The Different Types of Central Air Conditioners?
Generally, a central air conditioner can either be a split system or a packaged unit.

• Split Central Air Conditioner – this is the most common central air conditioning system, where air is distributed through ductwork. A ‘split’ system is the most common AC design in North America. The refrigerant circulates between the inside unit, where heat is absorbed and the outside unit where heat is expelled. As the refrigerant cools the air it can simultaneously dehumidify it. The cool air is then circulated by the furnace blower throughout your home. Your desired temperature is maintained by the settings on your thermostat.The AC evaporator coils are installed near the furnace or air handler. Integrating a split system central air conditioner with a furnace can be the most cost efficient whole home cooling solution.
  “A split-system air conditioner is the most cost efficient central AC system if you already have a furnace in your home”
  “A split-system air conditioner is the most cost efficient central AC system if you already have a furnace in your home”
• Packaged Central Air Conditioners – In a typical split system Air Conditioner the condenser is located outside the home and the evaporator is located in the home. A packaged central AC has both components in the same unit, which is usually installed outside on the ground in beside the home. Warm air is pumped from the home to the packaged air conditioner outside the home, where it is cooled and then returned to the home.

What is a Ductless Split Air Conditioner?
This type of AC system does not use ductwork to distribute cool air. Some older homes don’t have the ductwork necessary for a modern ducted AC system. This is where a ductless system is useful.

A ductless split ductless system may have multiple heads or indoor units that cool the air. These units may be mounted on a wall, floor or even ceiling. Each head cools the air in the room where it’s installed, which will allow you to set different temperatures for each unit and room.

The condensate drain, refrigerant tubing and power cable runs between the indoor heads and the outdoor unit. A small hole in the exterior wall is required to run the conduit between the indoor and outdoor units.

What is a Heat Pump?

Some of the air conditioners described above are also available in a variation of a traditional system known as a ‘heat pump’. A heat pump functions as both an air conditioner and a heater, which will allow you to heat and cool throughout the year without using your furnace.

During the summer months the heat pump operates like a traditional air conditioner to cool the home. During cooler months, the heat pump reverses the process to extract heat from the outside air and brings it inside the home to provide heat.

A typical heat pump takes heat from the outside air and runs it through the coils of the inside AC unit, which disperses the heat throughout the house. Even during winter time a heat pump is able to extract heat from the air. When it gets too cold for the heat pump to operate your furnace will turn on automatically to provide the necessary heat in your home. This means that home owners do not need to know which source is currently heating their home. The system just needs to run smoothly and efficiently.

Heat pumps have been quite popular in milder climates where the temperature does not stay below freezing for extended periods. However, recent advancements in heat pump technology have made them effective even in colder climates.

In colder climates like Canada, geothermal heat pumps are popular. This type of heat pump extracts heat from the ground versus a traditional heat pump which extracts it from the air. The initial investment of a geothermal heat pump is higher than an air sourced system. The installer the system also requires specialized skills and experience. But the long-term energy savings can certainly be significant.

Since all heat pumps move heat rather than create it, they are among the most energy efficient heating and cooling systems.

How Does a Heat Pump Work?

• Heat pumps function just like a traditional air conditioner, except the AC process can also be reversed to heat the home during the winter months
• A central heat pump uses the same ductwork with a furnace fan to distribute warm air throughout the house
• The compressor in the outside unit moves the refrigerant through the system
• The heat pump also has a reversing valve that reverses the flow of refrigerant which switches the system to providing heat versus cooling
• The heat pump also has an accumulator that allows the system to adjust the refrigerant charge automatically

Different Types of Heat Pumps
Air source is the most common type of heat pump installed in homes, followed by geothermal.

Air-Sourced Central Heat Pumps
An air sourced central heat pump is a common type of heat pump installed in many homes across North America.

This type of heat pump relies on ductwork to circulate both heat and cool air in a house. Just like a split system central air conditioner, it contains two key units. The condenser is the outdoor unit and the indoor unit is called the evaporator coil. The refrigerant circulates between these two units. It functions just like a central AC when it absorbs heat and releases it outside. But it also works in reverse order, as it collects heat from the outside air and releases it inside the house.

Air-source heat pumps can now be used in colder climates, due to advancements in the technology. Their ability to dehumidify has also improved. This means your home will be more comfortable during those excessively humid summer days.

Ductless Split Heat Pumps

A split ductless heat pump (mini split) can be installed in homes that lack adequate ductwork. This type contains two key units. The outdoor unit, contains a condenser coil, compressor, and fan. The indoor unit is the head, which contains an evaporator coil and a fan. A split ductless system can have multiple heads in the same way as a split ductless air conditioner.

The indoor heads can be installed on a wall, floor or ceiling. A remote control can be used to set and manage different desire temperatures in each room that contains a head. Refrigerant is circulated through tubing which connects the outdoor and indoor units.

One of the key advantages of split ductless systems are the energy savings when compared to ducted systems. One of the bigger disadvantages are the costs associated with installing a split-ductless heat pump. It can get expensive to install multiple indoor units.

Aesthetically, newer models look better than older versions. But many home owners do not like how the indoor head units look within their décor.

Geothermal Heat Pumps
Geothermal heat pumps operate in the same manner as an air sourced heat pump, except instead of absorbing and expelling heat into the air, it does so into the ground. The more even temperatures found in the ground, allow the heat pump to operate more efficiently during the hotter/colder days of the year.

Advantages of Geothermal Heat Pumps

• These systems are very quiet
• Very long-lasting
• Require very little maintenance
• Work well in colder climates
• Effectively control home humidity
• Can reduce average energy consumption by up to 50%, which will add up significantly over the long-term
• You can take advantage of any available government mail-in rebates

Disadvantages of Geothermal Heat Pumps

• Cost of installing a geothermal system can be significant since it requires a higher upfront investment
• The system will not work well on very small lots or every soil type

Heat Pump Enhancements
Higher end heat pumps contain certain features that will improve the comfort of your living spaces while saving you money on energy costs. Features to consider:

• A variable-speed compressor allows heat pumps to function at the ideal heating and cooling capacity. Since the compressor will not have to work at full capacity constantly, this will lead to energy savings, improve compressor lifetime and dehumidify the indoor air more effectively.

Portable Air Conditioners

What is a portable air conditioner and how does it work?
A portable, or ‘windowless’ air conditioner can be moved from room to room, but often requires venting to remove the hot air and moisture generated by the unit.These mobile air conditioning units are placed on the floor inside a room where the heat is typically discharged through a window vent kit that comes with the unit. You may find that portable units are noisier than other types of air conditioning units since the evaporator fan is working constantly to evaporate the condensed moisture that collects within the unit.Portable AC units are also not the most aesthetically pleasing cooling option. The unit itself will take up floor space in the area you’re cooling, and it may impact the look and function of one of your windows.

How Much Space Will a Portable AC Cool?
Portable air conditioners are effective in cooling a small space. The output capacity of a portable AC can range but most retail options fall between 11,000 and 14,000 BTU, which is typically enough to cool up to 500-700 square feet. This cooling capacity makes a portable AC a good option for garages, dens, recreation and computer rooms. They can roll across floors on casters, but are limited to the length of the tubing connecting the unit to the window kit.

Advantages of Portable Air Conditioners

• Effective in spot cooling a single room
• It’s a self-contained system which consists of only one unit
• Easy and quick to setup (installation kit and instructions included)
• Move from room to room if desired (wheels included)
• Many are 3 in 1 units (AC, dehumidifier, fan). Select units can heat a room as well.
• Won’t cover up your window with a bulky window unit (however, the venting kit will take up some space)
• Easy to store at the end of the season
• Removes excess moisture from the air

Disadvantages of Portable Air Conditioners

• Typically noisier than other AC systems
• The venting kit will obstruct the lower section of a window or sliding doorIt will take up some real estate on your floor
• Limited cooling capacity
• May impact the décor in your room (some people use DIY solutions with plywood and Styrofoam for door frame setups)

Portable AC Venting Options

• Vent through a standard window
• Vent through a sliding window
• Vent through a sliding door (not as easy to install as window option, since a standard kit will not cover the full height of the door. You may need to combine two or more kits)
• Vent through a dropped ceiling or wall

Where Does The Moisture Go?
A portable AC unit will remove both heat and moisture from the air in your room. A window kit is used to exhaust the heat outside. But where does the collected moisture go?

• Manually Removed – A traditional portable air conditioner will have a container inside for collecting water. Depending on the humidity in the room you are trying to cool, you may need to empty the container once or twice daily. This could become tedious and disrupt your AC runtime.
• Self-Evaporative – Higher end portable ACs will evaporate moisture and push it outside along the same exhaust hose used to push the heat from your room to the outside. This low maintenance option is usually more expensive.
• Drain Hose & Pump – With some portable AC units you have an option to attach a drain hose and expel water into a drain or a desired location outside. A pump accessory may also be used to move the drained water to a desired location more effectively, especially if the hose is elevated or lengthy.

What Size Portable Air Conditioner Do I Need?

Window Air Conditioners

What is a Window Air Conditioner and How Does It Work?

The second type of smaller air conditioning unit are window ACs that fit into an open window frame in your home. These units are used to primarily cool the room in which they are installed, and condensed moisture simply drips onto the ground below outside your home.A window AC takes warm air from inside the home and cools it by running it over an evaporator coil, before blowing it back into the home. The heat absorbed by the evaporator coil is then transferred to the condenser coil where it is expelled outside.

A window air conditioner is relatively easy to install, and can be used to cool a specific room in your home if a whole house AC system is not needed. In some living spaces, like older apartments, a window AC unit is the only option.

Some window ACs have offer different cooling levels and options. Some models will cool at your desired level until you turn it off, while other more advanced models will work to maintain your preset temperature. In this case, the air conditioner will remain on until the desired temperature is met. It will continue to cycle off and on in an effort to maintain your temperature.

What Size Window Air Conditioner Do I Need?

Frequently Asked Questions (FAQs) – Around How an AC Works

Are You Looking to Buy or Rent A New Air Conditioner?

One of the most important decisions you will need to make when selecting the right AC for your home is renting versus buying. Many individuals prefer the hassle-free experience associated with renting. While others, prefer to own their air conditioning units and don’t mind all the accountability associated with ownership.

Ultimately, the decision is yours. Here are some insights that will hopefully help you make the best decision for you and your family.

If you enter into an air conditioning rental agreement with a company like Reliance™, all the costs of repairs, annual maintenance and replacement of parts or entire units will be covered in your monthly fee. Since the air conditioning system is owned by the company, it will be in their best interest to ensure its working well and in great condition, as their long-term success and reputation is measured by great customer service.

If you choose to rent, ensure the company you are renting from is active in scheduling annual maintenance and tune-ups, is quick to replace broken equipment and is available 24/7. You should also consider how long the company you are considering has been in operation, the level of service it provides and how many customers it services on a monthly or annual basis.

Why Should I Rent?
Don’t want to worry about upfront costs, ongoing maintenance or expensive repairs? Renting an air conditioner could be the answer. Here’s what you need to know:

• Only cost the consumer needs to worry about is the monthly rent
• This hassle-free, convenient option can bring you year-round peace of mind
• When renting your cooling equipment, you pay nothing upfront and Reliance Home Comfort™ will maintain and repair your air conditioner at no cost**
• You can get any applicable government mail-in rebates without incurring the upfront costs
• Renting gives you the option to buy at any time
• Renting means not having to worry about your family’s comfort
• Rental air conditioning systems will be high quality, since the rental company will want the equipment to last for many years

Why Should I Buy?

• Buying is another great option for some home owners. If you’re considering purchasing your air conditioning equipment, here are something you may want to consider: There is a significant upfront cost to buying your air conditioner, but you’ll own your equipment
• Although any unexpected maintenance and repair costs are not automatically covered, you always have the option of purchasing a protection plan.
• Similar to rental, you can participate in any available government mail-in rebates and incentives
• There are often promotions available that you can take advantage of when purchasing your cooling equipment.

What Type of Air Conditioner Do I Need?

What Size Air Conditioner Do I Need?

A properly sized AC will provide you with the proper cooling and comfort levels throughout the summer. Whether you are looking to install a traditional split system central AC, a ductless split or heat pump, the size of unit you select is critical to ensure your living space is comfortable and energy costs are minimized.

Factors in selecting a proper air conditioning size:

• How many bedrooms are there in your home?
• What is the size of your home?
• What type of windows do you have?
• What are the insulators in your walls and your ceilings?
• Consider factors on the outside – what is the exposure of your home? (sourthern or northern) ?

Dangers of an Oversized Air Conditioner
An oversized air conditioner will cool your home but will not remove the humidity, which will make your home feel warmer and less comfortable.

Dangers of an Undersized Air Conditioner
An undersized air conditioner will not be able to keep up with demand on the hotter days which will prevent your home from maintaining your desired temperature.

Most Important Factor
When selecting an air conditioner, an engineering analysis should be performed (includes a heat loss assessment). This will provide your contractor with proper numbers that will help them recommend the right AC for your home.

Where Should I Install My New Air Conditioner?

Where Should I Install The Outside Unit of My Air Conditioner or Heat Pump?
To maximize energy efficiency and lifetime of your outside air conditioning unit, keep the following recommendations in mind:

• The outdoor unit should be 12 inches away from any object
• Do not place the unit near hot areas or ones which experience frequent foot traffic
• The unit should be placed on a level pad, elevated so that the condenser will avoid contact with heavy rain accumulation and snow during the winter

Where to Install a Wall-Mounted Indoor Air Conditioning Unit?
A ductless mini-split air conditioning system may have multiple indoor air handlers. Each handler will typically reside a separate room. Here are a few guidelines around where to position the wall-mounted AC units:

• It should be at least 7 feet above your floor with at least 6 inches of space above the unit and on each side
• At least 3 feet away from coaxial cables, electronics, Wifi modems and mobile devices to avoid the electrical noise associated with these devices
• The integrity of the wall should be strong enough to support the unit for many years. Where possible fasten to a stud or two by four.
• Position the unit away from direct sunlight or other heat sources like an oven
• Ensure the unit is not obstructed by anything, like a large piece of furniture

How Do I Maintain, Repair & Keep My AC Running Efficiently?

How to Maintain a Central Air Conditioning System?

How to Choose an Air Conditioning Maintenance Company?
Here are a few things to keep in mind when choosing an air conditioning contractor or company to maintain your AC system and perform annual tune-ups:

How to Clean Air Conditioning Ducts and Vents?
We recommend hiring a professional and reputable duct cleaning company to thoroughly clean the ducts and vents in your home. Those on a tighter budget, may want to consider a DIY option

How Do I Know if My Air Conditioner Ducts Need to Be Cleaned?

Here are a few questions you should ask yourself to determine whether it’s time to get your air ducts cleaned:

• Have you recently completed renovations
• Can you remember the last time you ducts were cleaned

Most Common Central Air Conditioner Issues and What You Should Do

Choosing and Replacing Filters

Air filters play an important role in your heating and cooling system. By preventing dirt and dust from entering your equipment, air filters help to ensure that your system isn’t putting in overtime to keep your home comfortable. These filters also help to remove pollutants from the air, maintain good air quality in your home, and make sure the air you and your family are breathing is cleaner.

To keep your system running smoothly and your air quality optimal, it’s important to make sure your filters are regularly maintained and replaced.

Choosing the right AC air filter

Depending on your home and the needs of your family, there are various air filters available to suit your needs. When selecting the right air filter for your home, you want to take into account the filter’s minimum efficiency reporting value (MERV) rating. The MERV rating give filters a score from between 1-20 that indicates the air filter’s ability to capture airborne particles while air is flowing through your cooling system. The higher the MERV rating, the smaller the particles the filter will capture before the air is circulated into your home. When you’re selecting a new air filter, it is recommended that your filter have a MERV rating of at least a 7.Beyond the ratings, there are several different types of air filters to consider when you are making your decision. The needs of your family, the number of pets in your home, and your budget can impact which is the right air filter for you. Below is a list of some of the most common types of residential air filters that you can choose from:

Fiberglass air filters – These filters are an economical option but only capture up to 20% of pollutants ranging from 3 to 10 microns and may not be as effective in improving your indoor air quality and should be replaced more often.

Electrostatic air filters – These filters contain self-charging paper fibers, which help to reduce the airborne irritants and allergensin your home’s air by attracting and trapping small particles.

What Are The Best AC Filters for Allergies?
If you or someone in your home frequently suffers from seasonal or airborne allergens, selecting the right air filter may help. When choosing your air filter, ensure that the filter has a MERV rating of at least a 7-12. A pleated or high-efficiency air filter will generally trap a higher percentage of particles and pollutants before the air is circulated throughout your home. You may also want to consider replacing your filters more frequently, at least once a month.

How to Replace My Air Conditioner Filter?

1. First you need to locate your old filter – In some cases the filter housing may live behind a main vent. In other cases you may find it behind your furnace. Don’t forget to turn off your unit before you remove the filter.
2. Figure out what size and type you need – your old filter should have the size printed on the side of it. Match this with the size of your replacement filter. There are many different filter types. When selecting the right one for your home consider how long each type will last and what type of air filtration you and your family require.
3. Install your new filter – insert your brand new filter into the filter housing and fastenthe cover or snap it back into place. Ensure you insert the new filter is in the right direction. There should be an arrow pointing which way it needs to be inserted.

How to Clean My Air Conditioner Filter?If you use a reusable air filter, it’s important that the filter is cleaned and maintained every 1-3 months to ensure unrestricted airflow and decrease the amount of particles in your air. To clean your reusable air filter, you can use a vacuum to remove the loose debris and then wash with warm water to clean the remaining dust and dirt. If it’s been a while since you last cleaned your filter or if there is a significant amount of build-up on the filter, you may want to consider cleaning it using a mild detergent with warm water. Once you’ve cleaned your filter, be sure to let it dry completely before reinstalling it in your heating and cooling system.

How often should I change my air filter?

The frequency in which you should be changing your air filter depends on a few factors in your home. The number of people living in the house, the number of pets you have, and if anyone in your home suffers from allergies, impacts how often you should be changing your indoor air filters. As a general rule, it’s recommended that you change your filter every 30-60 days for optimal air quality. If you have several pets in your home, or regularly suffer from severe allergies, you may want to consider replacing your air filters more often.

AC Energy Savings Tips

Even when the temperature is rising, you want to make sure that your energy bill stays low. When you are looking at a new AC unit and how to best keep it running throughout the season, there are a few things you can do to help save on energy.

• Consider an ENERGY STAR certified Air Conditioner
  When selecting a new air conditioner for your home, look to see if the unit is ENERGY STAR certified. AC models with this certification have a higher seasonal energy ratio (SEER) and energy efficiency ratio (EER) that will help to reduce your energy consumption throughout the summer months.
• Upgrade your home’s thermostat
  Upgrading your thermostat from a manual to a programmable or smart thermostat can help you have more control over both your home’s temperature and energy bill. Learn more about the different thermostats available, and which will help you maximize your cooling efforts this summer here.
• Use ceiling fans
  Ceiling fans can help to keep your home comfortable and take some of the pressure off of your AC by keeping the cooled air circulating throughout your home. During the summer, make sure that your fan is set to spin counter-clockwise for maximum cool air distribution.
• Close your curtains and blinds
  Depending on the direction of your home, a window that allows in direct sun exposure can heat up your home in no time. Limit the sunlight coming in by closing the blinds and curtains on your windows.
• Increase shade around your home
  If you’ve got space around the perimeter of your home, consider planting trees and tall shrubs to give your home more shade. By decreasing the direct sunlight your home gets, you can help to reduce your cooling needs.