Air Conditioner Types Explained – Comparing Each A/C Type

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There are two primary categories of air conditioning system:

• Room air conditioners: intended to cool small areas
• Central air conditioners: designed to cool an entire home or multiple areas at once

Each type has its own variations aimed at an apartment dweller or homeowner’s particular budget and needs.

To help you decide which system is right for you, we explain the features, key details, things to consider, average prices and operating costs, advantages and benefits, and potential downsides of each air conditioner type.

Key Takeaways

• Renters or those on a limited budget will likely prefer less permanent and more portable options like a window or portable A/C.
• If you have ductwork, a central air conditioner makes the most sense.
• However, you should consider buying a heat pump rather than a central air conditioner. Heat pumps are basically air conditioners that can also heat in the colder months of the year, and can save you money in the long run as they are much more efficient than other heating methods. Plus you may qualify for government rebates of over $5,000 for installing a heat pump!
• If you don’t have ductwork, a ductless mini-split A/C likely makes the most sense.
• Portable air conditioners should be your last resort as they are the least effective. Because the compressor is located inside the room, rather than facing towards the outside like a window air conditioner, a lot of heat is released back into the room making them less efficient.

Bottom Line: The type of air conditioner that is best will depend substantially on your home, needs, and budget.

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WINDOW AIR CONDITIONERS

Window-mounted air conditioners are used to cool single rooms. They are installed in an open window with the cool air return system on the inside and the hot air exhaust turned outside.

Factors that impact the size of window air conditioner you need:

• An average of 20 BTU is needed for each square foot of space to be cooled
• Rooms with higher ceilings may need more cooling power
• Rooms that get a lot of sunlight need an additional capacity of 10%
• If more than two people regularly use the room, add 600 BTU for each extra person
• ENERGY STAR® recommends an additional 4,000 BTU for units installed in kitchens

TIP! Before purchasing a window unit, check for an ENERGY STAR®rating.

These models use approximately 10% less energy than comparable units and include digital thermostats, multiple cooling speeds, programmable timers, and other features that enable better control over operation and energy use (source).

Advantages of a Window Air Conditioner

• Compact and comparatively inexpensive
• Relatively easy to install and uninstall
• Does not take up floor space, which is a plus in smaller rooms
• Great for renters since it can be taken with you when you move

Potential Disadvantages

• More challenging to remove and set up in a different room
• Not supported by all windows
• The panels that hold them in place can let in hot air if not installed correctly, making the units less efficient
• Takes up window space/may make a window otherwise unusable while installed

PORTABLE AIR CONDITIONERS

Portable air conditioner types are a recommended solution for homes and apartments that are unable to install a window unit due to unusual window configurations or building regulations.

Portable units are more flexible than window air conditioners because they can be moved from room to room. They use air inside the room to cool the condenser and blow hot air outside via a hose that vents through a window.

One downside of portable A/Cs is that because the entire unit is located within the room, rather than being partially outside facing like a window unit, some of the extracted heat ends up being released into the room, which makes them less effective.

BTU ranges and considerations are generally similar to window air conditioners (see above). Also like window units, most portable air conditioners have adjustable thermostats and multi-speed fans for maximum climate control and even include a timer for powering the unit on and off according to a preset schedule.

Advantages of a Portable Air Conditioner

• Less expensive than central air
• Easy to set up
• Doesn’t require permanent installation
• Great for renters since it can be taken with you if you move

Potential Disadvantages

• More expensive than a window unit
• Noisier operation, as all of their operating parts are indoors instead of facing outside
• Less effective as they don’t vent heat outside as well as window units
• Usually have a drip tray which needs to be emptied somewhat frequently (depending on use)
• Takes up floor/room space

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CENTRAL AIR CONDITIONING

Central air conditioners are designed to cool an entire home and are ideal for homes with forced-air heating. They consist of an exterior unit for releasing heat, and the interior coil which is mounted on the furnace and which captures heat and humidity from the indoor air using refrigerant.

Factors that impact the size of central air conditioning unit needed for your home:

• The home’s age
• Total volume of all living spaces
• The number and orientation of your windows
• How much sunshine can enter the home
• Type and condition of existing ventilation system and ductwork
• Is there room above your furnace for the coil? In some homes the furnace may be in a crawlspace or otherwise not have enough room to fit the new central A/C’s coil.

Buying the right size for your home is important. If the system you select is too big, it will over-cool the air and turn off too quickly. The walls, furniture, and other structures will not be sufficiently cooled, however, causing the AC to start up again and create an expensive series of ‘short runs’.

Undersized AC systems are just as problematic, as they will waste energy and cost money by running continuously, struggling to adequately cool the home.

Once you source a system that is the right size to cool your home, you will want to check its Seasonal Energy Efficiency Ratio (SEER) rating. The higher the rating, the less energy it will consume. ENERGY STAR® qualified systems range between 12 and 24 SEER.

Note room air conditioners are typically rated using Energy Efficiency Rating (EER), while central A/Cs are typically rated using SEER (source).

*Note these are just general estimates for average Canadians. Many factors can impact usage costs including the size of your home, how much you use it, the temperature at which you set your thermostat, how well-insulated your home is, local electricity prices, if you use it during peak or off-peak times, your unit’s efficiency rating, and so on.

Advantages of a Central Air Conditioner

• Cools the entire home
• Utilizes air filters to provide cleaner air
• Supports a programmable thermostat, which can save money on cooling costs
• Relatively little maintenance required

Potential Disadvantages

• Can be more expensive to install
• More costly to operate than a small portable or window unit (since it cools a much larger area… i.e. your entire home), but is still generally a better and more economical option than using multiple window or portable units
• Depending on where the outdoor unit is located, it can produce a fair amount of noise which may be annoyance when sitting nearby like on your patio, backyard deck, pool, etc.

DUCTLESS MINI-SPLIT AIR CONDITIONER

Mini-split air conditioning systems also known as ductless air conditioners, are ideal in home extensions, condos, and smaller homes or older homes and buildings with boiler/hydronic or electric baseboard heating that have no ductwork.

Ductless mini-split ACs work by extracting hot air and humidity from the room(s) and expelling both through the compressor into the outdoors. Compressor refrigerants cool air from the exterior and the fan blows the chilled air around the room.

Like single-package air conditioning systems, a favourable SEER rating is important when it comes to saving money. An ENERGY STAR® qualified split system will have a rating of 13.0 and up (source).

Advantages of a Mini-Split Air Conditioner

• Versatile installation: can be positioned on the wall or floor
• No ductwork required
• Zoned cooling without having to close off vents

Potential Disadvantages

• Initial expenditure: can be more expensive to set up than a traditional central air system
• Can only push air so far, so cooling larger rooms may be difficult
• Requires visible indoor units which can take up wall space and which some people may consider an eyesore
• Since one or multiple indoor units are needed, they can produce somewhat more noise than a central unit placed outside

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Choosing the Right Type of Air Conditioner for Your Home and Needs

When determining which type of air conditioner you require, you will need to consider the size of the area being cooled and whether you want a temporary or permanent cooling solution.

Which type of air conditioner is the cheapest to operate?

There are many variables that can impact which type of air conditioner has the lowest operating costs. Electricity usage is the main cost, and while small window units are likely to be the cheapest, they also only cool a small area. A central air conditioner will generally be the lowest cost to operate overall when you factor in the total volume of space that it can cool.

Window and portable air conditioners are similar in operating cost and overall electricity use, but window units tend to be slightly more efficient because they more effectively vent heat outdoors.

Compared to cooling a larger home with multiple window or portable units, for example, a central air conditioner is a better option.

Ductless mini-splits are similar in efficiency to central air conditioners, depending on the exact model, but have more limitations in the total space they can cool before needing additional units.

Final Thoughts

When it comes to air conditioning systems, no A/C type is superior to another. The most practical and cost-effective choice depends on your home’s configuration and layout as well as your personal preference. Consultation with an expert will help you select the appropriate type, model, and size for your budget.