The summer months in Alberta can be pretty warm and most Albertans turn to their air conditioning for relief when then temperatures rise.
Just under 40 percent of Alberta homes have air conditioning as part of their HVAC setup with a furnace and/or heat pump.
Understanding how an air conditioner works can help you troubleshoot problems and maintain efficiency, prolonging the life of your AC system. That’s good for your comfort as well as your pocket. Here’s what you need to know…
How Air Conditioning Works
An air conditioner works by using a refrigerant to absorb heat (and moisture) from inside the home, releasing it outside, and circulating cool air to lower the temperature inside. This involves several simultaneous processes during the cooling cycle, such as compression, condensation, expansion, and evaporation facilitated by components like the compressor, condenser coil, and evaporator coil.
We go into more detail below and also consider different types of air conditioners and common problems you may encounter…
MAKE THE RIGHT HEATING & COOLING DECISIONS…
For over two decades, Alberta Mountain Air has helped Calgarians solve heating and cooling problems and maintain ideal comfort levels. Get in touch online for a quote.
The Basic Principles of Air Conditioning
Air conditioning still works today according to the basic principles established by William Carrier in 1902, relying on the heat transfer process.
During this process, an air conditioning unit cools the inside air by removing heat and humidity from it using the unique properties of refrigerant, which can change between liquid and gas states. The cooled air is sent to the indoor space while the unwanted heat and humidity are transferred to the outside of the space.
Specialized AC components rapidly convert the refrigerant from gas to liquid and back again. This process relies on having the right type and amount of AC refrigerant working with well-maintained AC components and good airflow throughout the system—blockages can interrupt the cooling cycle and lead to performance issues.
Key Air Conditioner Components
Air conditioning units vary in type, size, cooling power, brand, and other characteristics but they all work according to the same basic principles and with the same basic components. The essential components of any air conditioner are:
Refrigerant
All air conditioner refrigerant absorbs heat but types vary. In Alberta, newer AC systems (installed after 2010) typically use R-410A (Puron), while older systems (pre-2010) likely use R-22. However, these are both being phased out in favor of more environmentally friendly options like R-32 and R-454B.
Your AC service professional can let you know which refrigerant your system uses and will check levels during the annual tune-up.
Compressor
The compressor’s purpose is to pressurize the refrigerant, raising its temperature.
The outside compressor unit acts as a pump to circulate the refrigerant throughout the AC system, taking low-pressure, low-temperature refrigerant gas from the evaporator inside the home and compressing it into a high-pressure, high-temperature gas. This flows to the condenser, where it releases heat into the outside air and condenses into a liquid during the heat transfer process.
The cool liquid refrigerant then flows to the expansion valve and into the evaporator inside the home, where it absorbs heat from the air inside the home, cooling the air.
Condenser Coil
The condenser coil is part of the outside unit in split AC systems, which are the most common type.
Its main job is to aid the release of heat outside during the heat transfer process, i.e. when the high-pressure, high-temperature refrigerant gas is cooled, it condenses to a liquid and releases heat to the outside air.
Expansion Valve
The expansion valve is a narrow opening located between the condenser and the inlet of the evaporator in the “liquid line”.
It functions on the low-pressure (“cold”) side of the system, regulating refrigerant flow and cooling the refrigerant down as it lowers the pressure, allowing it to evaporate again for the cycle to repeat.
Evaporator Coil
The evaporator coil is housed in the inside unit in split systems, aiding the heat absorption process inside the home.
The refrigerant passes over the coil and absorbs heat from the air. The refrigerant evaporates, changing from a liquid to a gas, and cool air is circulated throughout the home.
Blower Fan & Air Filter
The blower fan and air filter ensure that high-quality air, free of dust and allergens, is circulated freely around the AC system (helping to facilitate an efficient heat transfer process) and also around the home.
How an AC Cools Your Home
Let’s put all this together. An air conditioner works by cycling through two simultaneous and continuous processes—one inside the home (the “cold side” of the system) and another outside the home (the “hot side” of the system).
The following processes take place:
- Warm air from the home is drawn in through the return HVAC vents with the help of the fan and is filtered before entering the cooling process.
- The filtered, warm indoor air passes over the cold evaporator coil. As the liquid refrigerant inside the evaporator coil converts to gas, heat is absorbed from the indoor air into the refrigerant, cooling the air as it passes over the coil.
- The blower distributes cool air through the ductwork inside the home, cooling the rooms.
- The refrigerant gas is channeled to the compressor via a copper tube, where it is pressurized by the compressor, increasing its temperature.
- The hot, compressed refrigerant gas is pumped to the condenser coil in the outdoor unit, where it cools. Heat is released to the outside air and the gas condenses back into a liquid.
- The cooled liquid refrigerant expands, causing its pressure and temperature to drop significantly and it is channeled back to the evaporator coil through the copper tube again.
- Heat is absorbed again from the inside air as the cooling cycle repeats until the temperature specified on the thermostat is reached.
- The system starts again when the thermostat sensor detects that the air temperature has risen above the required temperature set on the thermostat.
This infographic sums it up:
Different Types of Air Conditioners
Most HVAC cooling systems in Calgary homes provide central, whole-home air conditioning but there are other types of AC units available to suit almost any living space.
Here’s a brief rundown of the main types of air conditioning systems used in Calgary homes:
Central Air Conditioning
Central AC provides whole-home cooling and relies on a thermostat to control the system’s operation and ductwork to distribute cooled air around the home. In HVAC systems in Alberta, these same duct systems distribute heated air from a furnace or heat pump during the colder months and cool, conditioned air during the summer.
Most central air conditioning setups use split systems with an outdoor condenser unit housing the compressor/condenser coil and an indoor unit housing the evaporator coil.
Ductless Mini-Splits
Ductless mini-split AC systems are commonly used in homes without existing ductwork or a central HVAC system.
They heat a single room, so if you have three rooms that need cooling, you need three separate AC units—but the lack of ductwork often makes them easier and more cost-effective to install.
Window and Portable ACs
Window AC units and portable AC units may work for single rooms and small spaces but window units especially are becoming less common in Alberta as technology evolves and provides more effective and convenient cooling options.
Heat Pumps
Heat pumps are another option for Albertans looking for heating and cooling solutions. These systems use heat transfer technology to offer both heating and cooling for homes, a cost-effective all-around option.
While the AC component is fine for Alberta homes, a heat pump should not entirely replace a furnace in your HVAC system because, when temperatures plummet to -20 degrees Celsius or lower, the extra heating capacity of a furnace is usually still required to adequately heat the home.
Energy Efficiency and AC Maintenance Tips
The cost of AC and heating in Alberta is high—not only to buy and install the AC unit but also to run the system. Maintaining efficiency and peak working conditions is a must to keep bills down.
To do that, follow these basic tips:
Here are some more ways to make the best use of your air conditioning.
Common Air Conditioner Issues
If you notice any of the following issues with your AC, don’t ignore them. They are tell-tale signs that something is wrong and needs the attention of an AC professional before they become an AC emergency:
FAQs
Keep Your AC Working at Peak All Year Round…
Central air conditioning systems do more than just cool the air inside your home. They also contribute to controlling humidity, air quality, and airflow within the home, greatly affecting comfort levels.
Keeping your air conditioner in peak condition with annual AC maintenance should, therefore, be a priority for you at the end of summer or in springtime.
All HVAC professionals at Alberta Mountain Air are SAIT-certified and can help you make the right heating and cooling decisions. So, if you’re in Calgary and considering your heating and cooling options, contact us online.
