Home Improvement
HVAC
Cost, Efficiency, and More
By
Bob Formisano
Bob Formisano
Bob Formisano is a licensed architect and builder with nearly 40 years of experience building new homes and restoring older homes. One of his specialties is repairing old systems dating back to the 1920s, including galvanized water pipes, knob-and-tube wiring, and more. His home repair articles for The Spruce span more than 10 years.
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Updated on 09/07/23
Reviewed by
Larry Campbell
Reviewed byLarry Campbell
Larry Campbell is an electrical contractor with 36 years of experience in residential and light commercial electrical wiring. He worked as an electronic technician and later as an engineer for the IBM Corp. He is also a member of The Spruce Home Improvement Review Board.
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Types of air conditioners for the home range from large central systems driven by outdoor compressors to small plug-in units that stand on the floor or mount in a window. No matter which form they take, air-conditioning systems have similarworking components,including a refrigerant, a compressor, condenser coils, an expansion valve, and evaporator coils.All of these work together to transfer heat and moisture from the inside of your home to the outside.
Our guide includes considerations about cost, installation, and the pros and cons of each type of home air conditioner to help you determine which is right for your space.
The 5 Best Air Conditioners of 2024
Types of Air Conditioners
01 of 09
Central Air Conditioning
- Best for: Effective whole-home cooling
A central air-conditioning system is the largest and most expensive type of conventional air conditioner. Like a split system, a central system ismade up of two units—the condensing unitand the evaporative unit—that are connected to each other byrefrigerant tubing.
The condensing unit is a large, boxy outdoor appliance that contains the compressor, condensing coils, and condensing fan. The evaporative unit typically sits in the plenum (the large central chamber between the furnace and the duct system) of your furnace. This means the air conditioning uses the same ductwork and blower fan as your heating system. Within the plenum, the evaporative unit consists of the evaporator coil and expansion valve. Condensed moisture on the evaporator coils is usually drained away through a tube running to a floor drain.
Central air conditioners are typically the most effective type of air conditioner for cooling entire homes. When installing a new central system, the primary consideration is making sure the system is sized appropriately for your home. If a system is too large, it won't perform well and won't adequately dehumidify the interior air. If it's too small, it won't cool adequately. Proper maintenance of a central air conditioning system is also important and often requires a professional.
Pros
Efficiently cools entire homes
Noisiest parts are outdoors
Cons
Complex installation and expensive
Must be appropriately sized for space
02 of 09
Window Air Conditioners
- Best for: Cooling a single room to a small home
A window air conditioner is technically called a "unitary" air-conditioning system and consists of a self-contained air-conditioning unit that is placed in a window or, less commonly, through a hole in anexterior wall. A window air conditioner contains all the refrigeration components in one compact box. It ejects heat out through condenser coils located on the outdoor side of the appliance. It blows cooled air into the room on theindoor side where the evaporator coils are located.
Room moisture that condenses on the evaporator coils generally drips to the ground from a tray located on the underside of the appliance. This is why a window air conditioner must be installed so it tilts very slightly toward the outdoor side. Tilted the wrong way, some air conditioners might drip water onto the floor inside the house.
Window air conditioners come in many sizes to cool any space from a single room up to an entire floor. A large window air conditioner might be able to cool an entiresmall home, especially if it's a single-story home. And it's an economical choice with easy installation.
Pros
Can cool a room or even a small home
Inexpensive and easy installation
Cons
Not ideal for large spaces
Moisture might drip on the floor
The 7 Best Window Air Conditioners of 2024
03 of 09
Portable Air Conditioners
- Best for: Rooms under 500 square feet
A portable air conditioner is another type of unitary air-conditioning system. It consists of a mobile,self-containedair-conditioning unitthat is placed on the floor inside a room. It discharges exhaust heat using a hose vent through an exterior wall or window vent. Like a window air conditioner, both evaporator coils and condenser coils are located in the same box, which is one reason these units are a bit noisier than other types of AC systems.
Portable air conditioners are typically used for rooms under 500 square feet, and they're an economical choice. Many people use them for temporary space cooling or wherever it's not practical to install awindow-mounted unit.
Because the portable unit sits indoors, its evaporator fan runs fairly constantly to evaporate the condensed moisture that collects within the unit. Units also might have a reservoir to capture condensed water, which needs to be emptied periodically. This is quite different from a window-mounted unit, where condensed moisture simply drips onto the ground.
Pros
Can be moved to where cooling is needed
Inexpensive and simple to set up
Cons
Not ideal for large spaces
Noisy
The 7 Best Portable Air Conditioners of 2024
04 of 09
Ductless Mini Split Air Conditioners
- Best for: Homes without an HVAC system
The split system—also calledductlessor "mini-split"—breaks the air-conditioning system into two packages, or terminal units. The condensing unit is located on the building's exterior and includes the compressor, condenser, and condenser fan. Theevaporative unit is located on the interior and handles the air cooling and distribution.
This is usually a rectangular box unit mounted high on an interior wall and contains a circulation fan, expansion valve, and evaporator coil. Refrigerant tubing passes through the wall between the condensing and evaporative units. A secondary tube running parallel to the refrigerant tubing drains away water that condenses from the indoor evaporator coils.
Thesplit system is commonly found in homes as well as hotels and other multi-unit buildings. It has become an increasingly popular option for homes without an HVAC system, such as those with hot water steam radiator heating or electric heating. It's cheaper to install than a whole-home HVAC system. Most split air conditioners are also heat pumps and therefore offer heating as well as cooling functions.
Pros
Less expensive than an HVAC system installation
Can provide cooling and heating to homes
Cons
Installation can be complicated
Not easily removed and thus not usually a good choice for renters
Continue to 5 of 9 below
05 of 09
Floor-Mounted Air Conditioner
- Best for: Cooling rooms with high ceilings
Floor-mounted air conditioners are also called through-the-wall air conditioners or split systems though they sit on or near the floor.A floor-mounted unit typically mounts low on the wall and can be partially recessed. The air conditioner is easy to access and maintain because it is located low in the room. It's a straightforward unit since it's much like other air conditioning units except that it's positioned to quickly cool down a room.
Pros
Energy efficient
Cools down a space quickly because it's positioned low
Sleek and somewhat discreet
Easier access for maintenance
Cons
Requires significant amount of wall space
Cool air stays lower in the room, resulting in uneven temps
Gets dirtier and dustier faster
Risk of becoming blocked by furniture
06 of 09
Smart Air Conditioner
- Best for: Efficient, remote-controlled cooling
Smart air conditioners make it easy to create and control comfortable temperatures in your home. You can set a custom cooling schedule that guarantees that your home is the perfect temperature every hour of the day and night.
A smart air conditioner saves money in the long run because it maintains a desired temperature while efficiently operating once it reaches that ideal temperature. That means it's consuming less energy than a traditional AC unit and lowering your bill.
These devices connect via Wi-Fi along with an app that allows you to control the air conditioner and check its status when you're not at home. Other features can help increase the efficiency of your energy use, including geofencing (controls the temp based on your location), energy monitoring, and service alerts.
Pros
Energy- efficient
Continuous comfort control
App-based controls
Cons
More parts to maintain and troubleshoot
Can be troublesome to set up and connect
Costly
07 of 09
Geothermal Air Conditioner
- Best for: A home you plan to stay in long-term
The geothermal HVAC systemsimply moves heat around. The system uses two components in your home: a heat pump and pipe buried in the ground. The pump circulates a fluid mixture that acts as a heat exchanger to absorb or extract heat to warm or cool your home. As an air conditioner, the heat pump draws heat out of your home and into the ground to cool your home. Basically, the ground acts as a heat sink in the summer to keep your home cool.
Pros
Requires little maintenance
Uses substantially less electricity to run
Extremely safe source of heating and cooling
Cons
Takes five to 10 years to recoup high cost of install
Potential groundwater issues
Not suitable for every property
08 of 09
Dual Fuel Air Conditioner
- Best for: Rural areas and homes with solar energy
Better known as a dual fuel HVAC system, this system uses two sources of fuel to heat and cool a home. A dual fuel combination could include an electric heat pump and a gas furnace or an electric heat pump and an oil furnace. Essentially, the heat pump replaces your central air conditioning system.
During the summer, the heat pump works as an air conditioner.The heat pump works in tandem with your furnace to remove hot air from indoors while cooler air is distributed by the furnace’s blower. During cooler months, the heat pump becomes the primary source of heat, supplying warm air until very cold air triggers the furnace to turn on.
This system works best for homes in rural areas that do not have access to natural gas and have limited access to propane and oil.
Pros
Offsets propane or oil fuel costs
Environmentally friendly, emitting zero emissions
Cons
Extremely costly to install
Can be difficult or inappropriate to convert some systems
Continue to 9 of 9 below
09 of 09
Evaporative Air Conditioner
- Best for: Low-cost cooling method for warm, dry climates
Evaporative air conditioners, also called evaporative coolers or swamp coolers, work on simple logic by cooling the air through the evaporation of water. This type of air conditioner can be purchased as a portable unit and you can even make a small DIY version. This type of air conditioner is common in hot, arid southwestern states, such as Arizona and New Mexico.
The device works on the premise that a continuous stream of fresh, warm, and dry air passes through an internal filter that's wet, and pushes out cooled air into a room via a fan and motor. A motorized evaporative cooler works best when the windows are left open. Modern evaporative air conditioners come as whole-house systems or individual units. However, it is unlikely and inefficient to use both an evaporative and traditional air conditioner in one house.
Pros
Consumes very little electricity
Adds moisture to a very dry space
Ranges in size from portable to whole house systems
Cons
Professional installation for large systems
Cannot combine with traditional AC units
Not good for humid climates
How to Choose an Air Conditioner
The size and type of space you're looking to cool will be one of the most important factors when determining which home air conditioner is right for you. For instance, if you just need to cool one room, a portable or window unit will likely suffice. Likewise, if you're a renter and can't install anything permanent, you also might need to go with a portable or window unit.To efficiently cool an entire home, central air is best.
Consider the unit's cooling capacity based on the square footage of your home. In addition, if you live in a very hot region, you may need a more powerful unit to handle extended periods of cooling during hot temperatures vs. living in cooler regions where a window unit or mini split may suffice.
Even if you own your home, cost will likely be a factor. For example, if you don't want to pay to have a full HVAC system installed, you might be better off with a less expensive ductless system. Consider the energy efficiency rating of each air conditioner to determine which option is best based on its initial price and monthly operating costs.
FAQ
What is the best type of air conditioning system?
Central air is the most popular and most efficient air conditioning system. But various types are best for different needs, budgets, and how much money you are willing to pay to repair your air conditioner.
What is the most advanced home AC system?
HVAC technology continues to advance to create sustainable solutions for cooling homes. For example, highly advanced air conditioning systems use renewable energy sources, such as solar energy.Geothermal HVAC systems are also very advanced and sustainable forms of heating and cooling homes.
How long do most AC systems last?
Most central air units last between 15 and 20 years, but they can last much shorter or longer depending on the upkeep of regular air conditioner maintenance.
What Size Air Conditioner Do I Need?