AccuServ Heating and Air Conditioning

What Is the Difference Between a Split Air Conditioner, Central Air Conditioner, and Window Air Conditioner?

December 1, 2019

When a heatwave hits, everybody scrambles to find a way to stay cool. What’s the best way to do that? Well, you can start by plugging in all the antique fans throughout your home, leaving the fridge door open and if all else fails, jumping in a bucket of ice cold water.

But you probably had the more practical idea of air conditioning in mind (but you have to admit the first few ideas sounded like a lot of fun).

Now that your mind’s set on getting a new air conditioning system, you’re faced with another question: What type of air conditioning system should you get? That’s right! There’s more models, sizes and features that you can imagine, and one of them is the perfect on for your home.

In this article we’ll be exploring the big 3 air conditioning solutions that will help you stay cool.

Window AC

This one is a portable and quick AC cooling solution. It also has a lot of history to it. Surely we can all see pictures of New York apartments with big metal boxes sticking outside people’s windows whenever we think about them.

Window AC takes all the heat near it and throws it outside.

They’re ideal for single room cooling or for small apartments. Note, that they are reliant on airflow, the air it pushes cannot travel through walls or doors to cool another space/room.

If your looking to cool more than one room or a very large space, you’ll need to looking at a central AC system or installing multiple window ACs.

Window AC have the advantage of low price and easy installation. They average around 16-20” Wide, 15-20” long and 16-20” high. The range of dimensions also guarantees that you’ll find one that fits your window.

If you’re handy with tools, you can probably install one yourself. If you prefer someone else to handle the grunt work, a handyman can install one for a relatively low price.

Follow these easy steps to install a window AC:

  • Open/remove the window pane where the AC will be installed
  • Insert the AC into the space with the controls facing you.
  • Screw it into place
  • Open the AC side curtains to cover any unused space
  • Plug your AC and letting it cool down your room!

There are also portable AC that work similar to window AC, expect they sit in your room and have a hose that extends to the window.

Window AC are great when your trying to get quick air conditioning to small area on a budget. However, it’s important to understand their limitations to avoid disappointment. As long as your expectations are only to cool the space/room the window AC is located is in, then you’ll be perfectly happy with this solution.

If your need of a more powerful cooling solution, then you’ll need one of the options we’ll discuss below.

Split Air Conditioner

A split-AC is like a window AC on steroids. They offer the same room/single space cooling that window AC does, but at a higher capacity.

They also operate at a high-efficiency, as high as 25 SEER. That helps you get a good ROI from energy savings in the long run.

However, with such advantages come increased costs and space demands. A split AC is comprised of two components, the indoor head unit and the outdoor condenser. These two components also need to be connected by copper tubes called refrigerant lineset.

To give you an idea of the typical size, the Mitsubishi Mr. Slim’s dimension are 33”Wx11”0Hx7.5”D. Its outdoor dimensions are 30”Wx10”Gx20”D. Its outdoor unit is a side-discharge that pushes the air sideways rather than upwards and is a rectangle. Note, most manufactures have similar sizes head units, however different manufacturers have outdoor AC sizes that can vary greatly.

As a result of the added complexity of a split AC system, we recommend you have a licensed air conditioning mechanic install your system. Poor installation of these systems can lead to poor performance and premature failure.

The initial upfront cost to install these is higher than window and AC and can be higher than even a central system. This is especially a problem if you’re considering multiple indoor head units. This is often the case if you want to cool your whole home.

Each head unit only cools its individual zone. To cool other rooms, you’ll need to have separate head units installed there. Each space that has its own head unit installed becomes its own individual zone, allowing you to attain zone cooling.

This is the biggest advantage with split AC as each zone can be set to its own temperature. This guarantees that the zones with a head unit will be cooled properly. Unlike Central AC that are reliant on the ductwork of the home and may have rooms that receive inadequate cooling (to be discussed later)

Split AC are great for cooling open concept homes with a few rooms or rooms where doors can be left open allowing air to travel and cool these spaces. However, if your home has many rooms and these rooms cannot have their doors left open, a central AC may better meet your needs.

Central Air Conditioner

This is one of the most common cooling solutions for a residential home. The central AC allows for thorough cooling and dehumidification of your home.

Like your furnace, your central AC is reliant on the ductwork that connects to each individual room/space to ensure proper cooling.

As heated air is picked up in each room and carried back to the your furnace, a cooling coil cools the air before it is pushed back throughout your home. The heat picked up by your cooling coil (evaporator) is than carried through the refrigerant lineset and is released at the outdoor unit (condenser).

The best way to comprehend this concept is to understand that cold is not the presence of cold, but the absence of heat. To cool down a space, you merely have to remove the heat that space and throw it somewhere else (outside).

The disadvantage of a central system is that it’s heavily reliant on the ductwork. If ductwork is improperly sized, installed or damaged; cooling will be drastically reduced.

This becomes very problematic when old homes with duct sizes only sized for heating acquire a new air conditioner. Ducts sized only for heating are smaller and may not have the capacity to carry the higher volume of air required for air conditioning. This is especially true for 2nd and 3rd floor as your blower motor struggles to push the heavier cool air to these higher areas.

It’s important when installing your air conditioner you have air conditioning mechanic that is also familiar with duct design and can ensure ductwork is adequate for your central AC solution.

If all ductwork is adequate, AC installation can move forward. Here’s how:

  • Recovering the old refrigerant if replacing and remove the older AC (when upgrading an older system)
  • Replacing or purging old refrigerant lineset Installing the indoor evaporator unit above the furnace
  • Installing the outdoor condenser unit
  • Connecting all linesets to both indoor and outdoor unit
  • Vacuuming the system of all contaminants and ensuring there is no leaks
  • Charging the system with refrigerant and balancing for proper pressures

The average cost for installing an air conditioner properly if no ductwork modification is required is $4-6K depending on the capacity of the AC. When ductwork is sized correctly and the AC installed right, you can expect proper cooling throughout your home.


There are variety of ways to stay cool. Each one with its unique pros and cons. To summarize:

Window AC: Cheap, easy install, provides adequate for single small spaces. Good for apartments, single space heating and people looking to stay cool on a budget.

Split AC: A good high efficiency, zone cooling solution. Good for open concept homes with a few rooms looking to invest in a long term solution.

Central AC: Good system if you currently have properly sized ductwork. Cheaper than split AC for cooling a whole home if you still want adequate cooling throughout their home.

There’s no right cooling solution, only a solution that is just right for you! We hope this guide will help you figure that out.