Guide for Purchasing and Installing a Central Air Conditioning System


This unbiased guide from Canada Furnace and Air Conditioning Calgary gives you the expert information necessary to select the right central Air Conditioning system. It covers costs, sizes, warranties, and more.

If you are in the market to install or replace a ‘whole-house’ (not just a single room) central air conditioning system you, have found the information you need. Central air conditioning works throughout your whole house. This article will give you information about both and make comparisons along the way to keep you well informed for your purchasing decision.

A diagram of a Central Air Conditioning system reveals the following:

  • A Condenser.
  • An Air-Handling Unit.
  • A Blower (like a Forced-Air Furnace).
  • Evaporator Coil.
  • And a Ductwork System

Facts and Information for Making Your Buying Decision Regarding Central AC

(1). Condenser

The Condenser is usually located outside and uses the latest in refrigeration technology for cooling the air.

(2). Air-Handled Unit

This unit is located in your basement, attic, or sometimes your garage.

(3). Blower (Heat Pump)

Air conditioners carry heat pumps. You can reverse an AC to be used to heat in Winter.

(4). Evaporator Coil

The exterior part of the evaporator coil contains your compressor, cooling fan, and condenser. The central AC unit refrigerates throughout a series of coils and condensers to take heat out of the air. Your evaporator coil holds refrigerant that will extract that heat and humidity.

(5). Ductwork System

The usual duct-work system in a Central AC system is what is called a ‘split system’ (indoor coil/outdoor compressor-bearing system).

What Goes on Within the System When in Operation

Electricity is its power source as the compressor pumps the refrigerant though your system is gathering both heat and moisture from indoors and removing it from your home. The heat and humidity are taken out of your home when the warm air from inside is blown over across the cooled indoor coil. Heat within the air transfers to your coil and ‘cools’ the air.

The heat that was transferred to your coil gets pumped to the outside while the cool air gets pumped back inside. This helps to maintain an indoor temperature that is comfortable.

Things to Consider When Choosing Central Air


If you’ve chosen to go with a Central AC System, then you want to dig down deeper into that decision. You need to figure out what it’s going to cost you to purchase and operate the system. That means knowing its energy efficiency capacity and what size will suit your situation. You need to find out its warranty, features, and any other benefits it carries.


You need to install a size that fits your energy efficiency needs and fits it comfortably. When you replace your system or install a new one, you need to be sure to have both a new indoor unit and outdoor unit that meets your needs regarding energy efficiency.

Energy Efficiency

Today’s energy can be very costly and difficult to maintain. That makes energy efficiency a top consideration when making your choice. Over the past decade or so the minimum SEER Rating had a lower number requirement on its units.

That number continued to rise over the years. Some older ACs might possess a SEER rating down as low as 6, the models produced after Jan. 2006 must possess at least a minimum of 13. The highest of the most efficient models can possess a SEER rating of from 15 to 17 (which means the higher models are 30% more efficient than those with a SEER rating of 10.

Features to Look For When Shopping a Central AC System

  1. Coils – The larger the coil the more efficient the heat transfer will be.
  2. SEER – You want a high temperature rating (over 11.6). You also want a ‘thermal expansion valve’. Once the weather reaches its hottest this will turn your system into a high-efficiency operation.
  3. Fan-Only Switch – This enables you to turn your cooling off while leaving your fan running to keep the air circulating the natural air at no cost.
  4. A Multi-Speed Blower – This enables you to lower your electricity consumption to using just what you need.
  5. An Automatic Delay Switch – This allows you to keep your fan on as long as it takes to cool down the air remaining after your compress turns off.
  6. Filter Indicator Light – This will alert you whenever your filter needs to be changed. It helps to boost your efficiency by helping you properly maintain your system.

There are plenty of high-efficiency products that combine several different features and add them to their own (Programmable Thermostats would be a good example).

Central Air Conditioning Warranties

AC warranties are how AC systems last people across many years. Anybody looking to obtain a Central Air Conditioning System should request and read the warranty before making a purchase. These warranties can vary quite significantly from one manufacturer to the next. One warranty may cover one aspect of the system while another may not.

AC Refrigerants

By now everybody knows the threat to the Earth’s Ozone from refrigerants. They can be very harmful. Products that still use these refrigerants today are being phased out globally. When you purchase a new AC system, you should make sure you purchase one that has the potential for less harm to our environment.

R-22 Refrigerant – The Alternatives

One of the most popular alternatives to R-22 is the R-414. This is a blend of HFCs (Hydrofluorocarbons). It is produced and sold under multiple trade names like -SUVA 414, AGENETRON, AZ-20, PuronForane, 410A, and these DO NOT harm the ozone layer. However, the manufacturing of R-22 DOES does have an effect on global warming.