Generally, central air is better than AC. It’s quieter (unless your bedroom is adjacent to its outside compressor), and its permanence makes it more convenient. It is aesthetically more pleasing than a window unit. But is it more energy efficient? Let’s look at that. 

We will define central air as the whole-house cooling system with an outdoor compressor component and indoor ductwork that allows the cooled air to move through the rooms. AC refers to a window-mounted air conditioner (interestingly, it was the first type of air cooling invented in 1931.)

At first glance, central air conditioning is better than a single-window AC unit. However, is it actually more energy efficient?

Indeed, central air conditioning is more energy efficient in larger buildings and homes. But what about a small home? Comparing the overall energy efficiency of central air to a window AC in a smaller home depends on a few factors:

Is central air better than AC in terms of energy efficiency?

Size of space:
If you compare apples to apples (newer energy-efficient central air to newer energy-efficient window single units), you may only require one or two window AC systems for a mid-size one-level apartment or home. 

  • In this scenario, one or two high-efficiency window ACs will use less energy, especially if you can turn one off in a different room.
  • Central air is better suited to handle efficient cooling of large buildings.

Possibility of air leakage:
Central air will be better at reducing air leaks if your ductwork has been inspected for possible splits that cause cooled air to end up in walls or ceiling space.

  • Window units can also be airtight, depending on how diligent the yearly installation is.


Seasonal Energy Efficiency Ratio (SEER):

A SEER rating lets you know how energy-efficient your air conditioner is. A SEER rating of at least 14 is required as of 2023 to deem an appliance energy-efficient. What else uses a SEER rating? Here are just a few:

  • Furnace
  • HVAC 
  • Heat pump
  • Dryer
  • Dehumidifier
  • Washing machine
  • Dishwasher
  • Refrigerator
  • Pool pump
  • Water heater

Point-by-point, is central air better than AC?

Cooling a large living space or multiple rooms:
Central air wins at its ability to cool a whole house or large apartment. 

  • Window-mounted ACs can only push their cooled air a certain distance into a room.
  • Hence, single ACs would be required in a number of rooms. 
  • Because central air delivers its cooled air through the existing ductwork in your home, it provides an even and consistent cooling in every room. For larger homes or spaces with multiple rooms, central air conditioning is more effective in maintaining a comfortable temperature throughout the entire property.


Allowing different temperatures in different rooms:
Both central air systems and single ACs can provide varying temperatures in different rooms.

  • For example, if overnight, you may want more cooling in your bedroom and less throughout the other areas, both systems can easily achieve different room temperatures.
  • Turn down (or off) one of your window ACs.
  • Close or partially close the floor vent cover to achieve lesser cooling in certain rooms.


Central air is a discreet way to cool your living spaces.  

  • The compressor unit is located outside the building. 
  • The ducts are installed in the walls or ceiling. 
  • The house’s interior is clean and free from bulky window units that can obstruct views and natural light.

Generally, window ACs are definitely noisier than central air.

  • A window AC can be heard easily within that room, and for that matter, in other rooms too. For some, that might be a charming by-product of summer, but for most people, it is not.
  • The outside compressor of a central air system makes a lot of noise.
  • Consider the location of the installed outdoor unit, both for people sleeping in your house and, yes, sleeping in the house next door.
  • Mount it at the back of your home, away from peoples’ bedrooms and from summertime backyard gathering spaces. (Sound deadening material can be installed at the proper distance from the compressor)


Permanence and convenience:
Central air, once installed, should require no more than yearly maintenance, making it the desired style of cooling for convenience’s sake. Finan Home Dervices takes care of your yearly AC maintenance or service for you. Contact us at (226) 213 3833 or online. 

  • Window units must be removed and installed yearly. Alternatively, covering them on the outside may work. The severity of winter weather should be considered.
  • Removing and storing a window AC unit is the best option to prevent winter moisture buildup and possible rot to the window sill.
  • Central air temperature is usually set to a program on a thermostat (the same one used for a wintertime furnace), so it is more convenient in that regard.
  • A thermostat allows programming for optimal electricity use (energy efficiency)
  • Both window ACs and central air systems should be turned off during vacation time.


Quality of air: 

  • Central air conditioning systems have air filters to improve indoor air quality, trapping dust, pollen, and other allergens. 
  • Window ACs have filters as well. Look for a high-quality filter system for a window AC unit.


Ability to open windows for fresh air:
You cannot open the window that houses an AC unit. Central air has the most significant benefit of allowing natural airflow throughout. 


While the initial installation cost of central air conditioning can be higher, it will provide cost savings for larger buildings. 


Real estate resale value: 
A home equipped with central air conditioning generally has a higher resale value than a home relying solely on window-mounted units. 

  • Central air conditioning is considered a desirable feature for potential buyers.

Despite the advantages of central air conditioning, it’s essential to consider factors such as initial installation costs, the size of the space to be cooled, and individual preferences before deciding. 

Window-mounted units can still be a practical and cost-effective cooling solution for smaller spaces or situations where central air conditioning is not feasible.

This post was written by Finan Home Service

July 31, 2023