AC Buying Guide: Everything You Need to Know about a Home Air Conditioner Installation

Read on to learn about:

• Types of AC units
• AC cooling capacity and how it is measured
• Ensuring you have the right cooling capacity for the size of your home
• The energy efficiency rating for air conditioners
• AC Noise Levels
• AC Maintenance Requirements

Types of Air Conditioning Units

There are a variety of types of air conditioners used in homes. This article focuses on one type of AC unit, a split air conditioner.

To truly understand the difference between the types of residential air conditioners, I will explain each type and where they are best used.

Split Air Conditioning

Split Air Conditioners have 2 major components, split between them, an indoor component and an outdoor component.

The indoor unit contains the cooling coil (or A coil). The outdoor unit houses the compressor and condenser. The A-coil sits on top of the furnace and cools the air. The furnace blower and ductwork are used with the air conditioner.

To understand how this works, read How Does A/C work?

Ductless Mini Split Air Conditioner

A ductless mini split air conditioner operates on the same principles as a split AC system, except that they do not require venting for distribution.

Just like a typical AC split system, there is an outdoor unit that houses the compressor and the condenser.

Individual indoor AC units are placed in specific areas, providing cooling for the room. The indoor units can be controlled individually, allowing different temperatures in each zone.

A mini-split is not as aesthetically appealing and isn’t ideal for a large home.

Central Air Conditioning

Central air conditioning systems are synonymous with ductwork that allows cool air to flow through your entire home.

Central air conditioning operates on a split AC system, but not a ductless mini-split system.

In Calgary, Edmonton and Red Deer, most of us use a furnace for central heating. (One exception is a boiler system.) Consequently, when AC is installed in a home in Calgary, Edmonton or Red Deer, the existing ductwork will be used to convey the cool air through the home.

A mini-split AC system, on the other hand, doesn't require ductwork and can be controlled locally, where the indoor units are placed.

Window Air Conditioning

An affordable option, window AC units can cool a room or small space.

Window AC units are self-contained, meaning all the parts work together in one unit. Window ACs have limitations, but they are easily installed and a relatively inexpensive option.

Packaged Terminal Air Conditioners (PTAC)

Think of a hotel room when you are picturing a packaged terminal air conditioner.

They are self-contained units that are installed through a window and often provide both heating and cooling functions.

Portable Air Conditioners

Portable air conditioners are stand-alone units that can be moved from one room to another.

They usually vent through the window with a temporary vent kit that can be moved from one window to another.

Portable air conditioners are usually very affordable and have the ability to cool a room.

AC Type Comparison Table

Why is Air Conditioning Cooling Capacity Measured in Tons?

Good question!

Just like horsepower, a measuring unit transitioning from horse to steam power, a ton of refrigeration (or refrigeration ton) was a unit of measure predating mechanical refrigeration.

In the 1800s, ice harvesting became a thriving industry. Ice was transported and used to cool icehouses and iceboxes, providing refrigeration.

https://www.boweryboyshistory.com/2021/07/the-ice-craze-triumphs-and-scandals-of-the-19th-century-ice-trade.html

Refrigeration ton is the amount of heat transferred to heat or melt one ton of ice in 24 hours.

Obviously, the historical reference to ice is relevant to modern air conditioning systems, but the term “ton” stuck around and is still a measurement of cooling capacity.

What is a BTU?

BTU stands for British Thermal Unit and is a unit of measurement commonly used in the heating, ventilation and air conditioning industry.

One ton of refrigeration, or cooling capacity, is equivalent to 12,000 BTUs per hour.

In the heating and cooling industry, BTUs are used to measure heating and cooling capacities.

The cooling capacity of an air conditioner is often measured in terms of BTU/h.

It is extremely important to ensure that the BTU rating meets the requirements of your home!

https://en.wikipedia.org/wiki/Ton_of_refrigeration

Size Matters: Choosing the Right AC Unit for the Size of Your Home

Be sure to choose the right AC unit, with the correct cooling capacity for the size of your home.

Many factors influence the amount of cooling capacity needed to cool your home.

• Size of your home
• Insulation levels
• Climate
• Ceiling height
• Window orientation
• Window size

We strongly recommend having an HVAC specialist do a detailed load calculation to determine the needed AC cooling capacity.

The rule of thumb is 1 ton of cooling capacity for every 400–600 square feet.

SEER: Energy Efficiency Rating For Air Conditioning

A SEER rating is often used as a measure of efficiency for air conditioning systems.

SEER stands for Seasonal Energy Efficiency Ratio.

The higher the SEER rating, the more energy-efficient the air conditioner is.

SEER Formula

SEER = Total Cooling Output (in BTUs)
       --------------------------------
       Total Energy Input (in watt-hours)

SEER Rating Comparison Table

In Calgary, Edmonton, or Red Deer, where air conditioning is only needed a few months of the year, the energy savings from an AC unit rated above 20 most likely would never be seen.

https://theheatpumpguy.com/f/seer-ratings-for-air-conditioners-are-misleading

Single-Stage vs Two-Stage vs Variable-Speed Air Conditioners

Single-Stage Air Conditioners

Single-stage air conditioning has an off and an on. When operating, it runs at full capacity.

The biggest advantage of a single-stage air conditioner is the price.

Two-Stage Air Conditioners

Dual-stage or two-stage air conditioners provide more efficiency.

The compressor operates at two levels depending on cooling demand.

Multi-stage Air Conditioner

Multi-stage air conditioners operate on variable settings or speeds, matching the cooling demand required.

Modulating / Variable-Speed

Variable-speed AC units continuously adjust compressor and fan speeds for maximum comfort and efficiency.

Side Discharge Condenser Vs Top Discharge Condenser

Top discharge units are larger and common in suburban areas.

Side discharge units are narrower and commonly used in tighter urban spaces.

Are Some AC Units Noisier Than Others?

Yes, some air conditioners are louder than others.

Noise levels are measured in dBA.

Noise Comparison Table

AC Maintenance Requirements

Did you know you should have your AC unit serviced every year?

Proper maintenance on your AC unit will ensure that your AC operates at peak performance.

Dirt, leaves, dust and debris can disrupt airflow and reduce efficiency.

Be very careful cleaning your outside condensing unit because the coils and fins bend easily.

Have a professional inspect and clean your AC unit every year.

Yearly maintenance can help detect:

• Leaks
• Faulty components
• Wear and tear
• Airflow problems

Read more about servicing and maintaining your AC: How Does an AC Work?